Undernutrition and anaemia (the commonest micronutrient deficiency), continue to remain prevalent and persistent in sub-Saharan Africa (SSA) alongside a rising prevalence of overweight and obesity. However, there has been little research on the co-existence of all three conditions in the same household in recent years. The current study examines the co-existence and correlates of the different conditions of household burden of malnutrition in the same household across SSA.The study involved twenty-three countries across SSA who conducted Demographic and Health Surveys between 2008 and 2017.The analytical sample includes 145 020 households with valid data on the nutritional status of women and children pairs .Logistic regression analyses were used to determine household correlates of household burden of malnutrition.Anaemia was the most common form of household burden of malnutrition, affecting about seven out of ten households. Double and triple burden of malnutrition, though less common, was also found to be present in 8 and 5 % of the households, respectively. The age of the household head, location of the household, access to improved toilet facilities and household wealth status were found to be associated with various conditions of household burden of malnutrition.The findings of the current study reveal that both double and triple burden of malnutrition is of public health concern in SSA, thus nutrition and health interventions in SSA must not be skewed towards addressing undernutrition only but also address overweight/obesity and anaemia. Historically, malnutrition has been linked with different population sub-groups, and the divide has mostly been by socio-economic status; undernutrition was linked to resource poor populations, while overweight and obesity were associated with the affluent. This predisposition often led to a functional divide when addressing malnutrition challenges. However, over the past two decades, there have been indications that undernutrition and overweight/obesity are increasingly co-occurring and becoming a public health problem with no socio-demographic and or wealth/income groupings spared. Additionally, although globally, no regional block has been exempted from the rising prevalence of overweight/obesity which has translated into the current obesity pandemic, sub-Saharan Africa (SSA) has been observed to be experiencing a rapid rise in overweight/obesity, and the region also continues to be the only region where undernutrition is on the rise in almost all its sub-regions. The rise in the burden of overweight and obesity in low-resource countries was highlighted by Barry Popkin in his seminal work on the nutrition transition, in which he projected that the rate of dietary changes such as consumption of energy-dense foods and increasing decline in physical activity among the poor could result in an upsurge of overweight and obesity in developing countries,8.The 2020 Lancet series on the ‘dynamics of the double burden of malnutrition and the changing nutrition reality’ suggests that the global health community has been slow in acknowledging and responding to the high prevalence of the double burden of malnutrition, particularly in low and middle countries,10. Furthermore, the commercial determinants of health, defined as ‘strategies and approaches used by the private sector to promote products and choices that are detrimental to health’, are now viewed as a critical element in understanding ways of addressing the current levels of malnutrition. Additionally, the increasing penetration and intense advertising of sugar-sweetened beverages by both international and local food companies have a significant influence on the intake of sugars and thus contribute to overweight and obesity. This trend has edged some researchers to advocate for increased attention to be given to both the commercial and social determinants of health,12, especially as it relates to malnutrition, particularly overweight and obesity.These changes in lifestyle habits could also be viewed as socially constructed choices that are modulated or influenced by various commercial interests. The work of the Intergovernmental Panel on Climate Change provides adequate evidence about the link between climate change, food insecurity and undernutrition, particularly among vulnerable populations in sub-Saharan Africa, due to crop failures, reduced food production and increased foodborne diseases. The interaction between climate change and food security is complex and its impact on malnutrition is multifaceted. On the one hand, there is evidence that whereas severe food insecurity could lower obesity, on the other hand, mild to moderate food insecurity has been shown to be associated with obesity. The dynamics of how this paradox impacts household burden of malnutrition needs to be researched.In addition to the aforementioned challenges, the SSA region is also the hardest hit with regard to the consequence of climate change. The increasing temperatures and extreme rainfall that characterise climate change are altering suitable conditions for farming. Additionally, given its impact on agricultural systems, climate change significantly slows down progress towards improving the food security of households in SSA,15. Malnutrition at the household level is often observed among children and women, but this does not mean men are not affected,17. The pattern of malnutrition among children and women in SSA is changing from the previously observed undernutrition among women and children to undernutrition among children and overweight/obesity among women and even more recently to overweight/obesity among both women and children. A more nuanced examination shows the existence of even more permutations of undernutrition and overweight/obesity among women and children in the same household.Increasingly, undernutrition and overweight/obesity are being observed to occur in the same community, in the same household and among different members of the same household. Currently, the prevalence of iron-deficiency anaemia is the highest among all nutritional deficiencies around the world and in developing countries. Unfortunately, over the past decade, SSA has achieved the lowest progress with respect to reducing the prevalence of iron-deficiency,23. Consequently, SSA is particularly vulnerable to the burden of all forms of malnutrition; undernutrition, overweight/obesity and micronutrient deficiency and even worse, their simultaneous co-existence. And regardless of the condition of malnutrition, the consequences are largely negative. Childhood undernutrition for instance is associated with increased risk of mortality and poor cognitive development, while overweight/obesity is associated with increased incidence of chronic non-communicable diseases. Maternal overweight/obesity on the other hand is linked with various adverse maternal as well as fetal outcomes. Consequently, the co-existence of undernutrition, overweight/obesity and anaemia exacerbate the burden of ill-health and retards development among household members.Aside undernutrition and overweight/obesity, other nutritional disorders with equally grave public health implications include micronutrient deficiencies with iron-deficiency anaemia being the most widespread,28, while triple burden of malnutrition (TBM) refers to the co-existence of overweight/obesity, undernutrition and micronutrient deficiency,30 in the same household. It is also worth stating that, there could be the co-existence of overweight/obesity and micronutrient deficiency in the same individual and this could occur in either a child or the mother (adult woman). A child can also simultaneously be overweight/obese and stunted. This is also another form of individual-level double burden of malnutrition.Household burden of malnutrition can be classified by the collective burden among individual members of the household. Double/dual burden of malnutrition (DBM) is considered as the co-existence of maternal overweight and obesity along with child undernutrition within the same household,32. Additionally, whereas structural and institutional changes such as unregulated marketing of cheap processed foods and sugar-sweetened beverages and the lack of physical activity and physical activity spaces are identified as critical factors driving overweight/obesity,34, the region’s continued high levels of food insecurity, HIV prevalence and per capita income have been identified to be associated with undernutrition. Furthermore, although the double and triple burden of malnutrition is often reported as a regional or global phenomenon, its expressions and impacts are experienced at the micro-level in households. Thus, exploring correlates of malnutrition, particularly the double and triple burden of malnutrition at the household level, is critical for both public health programmers and policy makers to guide the development and implementation of appropriate policy interventions.Double and triple burden malnutrition households are becoming more common and rising rapidly in SSA partly due to the ongoing rapidly evolving nutrition transition which aims at reducing all forms of malnutrition is to be achieved, the household drivers of the burden of malnutrition need to be effectively understood. Considering the above-mentioned context, we use nationally representative data across SSA, to explore correlates of the different classifications of household malnutrition, i.e. undernutrition, overweight/obesity, anaemia (as an indicator of micronutrient deficiency) as well as their co-existence in the same household. Such analysis will contribute significantly to effective ways of addressing the co-existence of undernutrition, overweight/obesity and anaemia in households in SSA.Addressing the double and triple burden of malnutrition in SSA will require understanding the intricacies and characteristics of households that have been affected. To our knowledge, overweight/obesity, undernutrition and anaemia in woman–child pairs within the same household have not yet been explored using nationally representative data across SSA. But considering that SSA already has weak health infrastructure, the emergence of this nutritional paradox compromises the regions development even further. Furthermore, if target 2·2 of the Sustainable Development Goals. IPUMS uses a data warehousing approach to extract, transform and load data from numerous nationally representative surveys into a single-view schema to ensure that data sources become compatible. A total of twenty-six sub-Saharan African countries were initially extracted from the IPUMS website for analysis in the current study. Appendix 1 shows the characteristics of households as well as the characteristics of women and children under 5 years that were available for each country. Notably, Hb concentration readings for measuring anaemia were not captured for women in the Angola, Kenya, Nigeria, Zambia and Sudan data sets. Additionally, the Sudan data set had no indicator of nutritional status for women and children, while Angola had no data on nutritional status indicators for women. The final analytical sample therefore includes twenty-three countries with valid data on all variables of interest.The current study used data from the most recent Demographic and Health Survey (DHS) conducted across SSA where data were available. The DHS are standard nationally representative cross-sectional household-based surveys that are conducted approximately every 5 years. Data from the DHS provide indicators on population and health for multi-country comparison. The DHS programme started in the 1980s and has contributed to advancing global knowledge on health and population trends in low- and middle-income countries. All DHS are conducted using a standardised survey design and data collection procedures across participating countries. Typically, the DHS uses a stratified cluster sampling technique to select census enumeration areas based on probability proportional to the size of the enumeration area. This is then followed by a random selection of households within selected enumeration areas. Data collection for the survey is done through face-to-face interviews using questionnaires which are administered to household heads and selected household individuals including women in the reproductive age (15–49 years) who consent to be interviewed. For the purposes of the current study, the following inclusion criteria; (i) only sub-Saharan African countries, (ii) most recent survey conducted between 2008 and 2017 and (iii) the survey included indicators of children’s nutritional status  and women’s nutritional status (i.e. BMI and Hb level) were applied in extracting data for the analysis. Based on these criteria, a total sample of 145 020 households with women–child pairs from twenty-three countries was realised  in the household.The study focused on measuring five categories of household burden of malnutrition as dependent variables. These were undernutrition, overweight/obesity, anaemia (micronutrient deficiency), double burden and triple burden malnutrition. These conditions were measured among women (15–49 years) and children (6–59 months) in the household. Undernutrition among children was measured using height-for-age and weight for height z-scores < –2) or wasted (weight-for-height age z-scores <– 2). An undernourished woman is considered as one with a BMI <18·5 kg/m2. An overweight/obese household is characterised as a household having an overweight child and or an overweight/obese woman. An overweight child is one with a weight-for-height z-score > 2, while an overweight/obese woman is one with a BMI > 24·9 kg/m2. Anaemic households are households with either an anaemic child or anaemic woman or both. Children with Hb concentration of ≤ 110–119 g/l and women with Hb concentration of ≤ 100–109 g/l were considered to be anaemic.Household undernutrition also referred to as undernutrition only or undernourished households is characterised by households with either an undernourished child and or undernourished woman. A child is considered to be undernourished when she/he is either stunted , household access to improved water and sanitation (toilet facilities) and the wealth quintile of the household. The location of the household was considered as whether households were in a rural or urban area. The available individual characteristics include the age of children (under 5 years) and women (15–49 years) in the household.P < 0·05).The characteristics of the study sample including the characteristics of the households and the women and children in the households were described using means and percentages. The various categories of household burden of malnutrition were categorised as binary outcomes, that is, households with an undernourished child and/or woman were classified as 1 and 0 otherwise, households with an overweight/obese child and/or woman are represented as 1 and 0 otherwise, households with either an anaemic child and or anaemic woman were represented as 1 and 0 otherwise. Similarly, households that qualify as having a double burden of malnutrition were assigned a score of 1 and 0 otherwise. The same scale was used for households that had triple burden malnutrition. Per these categorisation and given that the various types of household burden of malnutrition were categorised as binary outcomes, the analysis technique employed to explore the correlates of the various malnutrition outcomes was a binary logistic regression. All statistical analyses were performed using the Stata statistical software package version 14·2 . Statistical significance was set at the 5 % α-level  who is anaemic or both. The results in Fig. The country-level results presented in Table The results presented in Table The results with regard to household wealth status indicate that, on the one hand one, increasing household wealth status was associated with a lower likelihood of a household being undernourished or anaemic, but on the other hand, increasing household wealth was associated with a higher likelihood of the household being overweight/obese. Similarly, the chances of a household being a dual burden malnutrition household increased with increasing household wealth but considering triple burden of malnutrition, only households in the richer wealth category were found to be at increased risk. The location of a household, whether rural or urban, was found to be associated with undernutrition such that rural households were more likely to be undernourished. However, rural households were less likely to be overweight/obese, anaemic or double burden malnutrition households.Considering the characteristics of reproductive age women and under 5 children in the household, the findings indicate that the chances of a household having an undernourished child and or an underweight woman increases with increasing age of a child under 5, but the chances of a household having an overweight/obese adult woman and or child decreased with increasing age of a child under 5. Additionally, there was a higher likelihood of a household having an anaemic child and or anaemic woman with increasing age of a child under 5; however, the odds was lower at older ages for the child. There was a lower likelihood of a household having a double burden of malnutrition with increasing age of a child under 5 from 6 to 23 months, but statistical significance was only achieved for infants who were aged 6 to 11 months compared with 0–5-month-old infants. Again, the chances of a household having a triple burden of malnutrition generally increased with increasing age of a child under 5 in the household.Considering the age of women in the reproductive age in the household, the findings indicate that the chances of a household being an undernourished household decreased with increasing age of women from age 20 to 49 years. Similar results were observed for anaemia, but the results were only statistically significant for women aged 25–49 years. The chances of a household being overweight/obese was observed to increase with increasing age of reproductive age women in the household. Again, the chances of a household having a double or triple burden of malnutrition increased with increasing age of reproductive age women from age 25 to 49 and 35 to 49 years, respectively, compared with when a woman in the household is 15–19 years old. The marital status of women in the household only showed a statistically significant association with the chances of a household being overweight/obese. Households with a woman in the reproductive age who was married showed a 26·7 % higher chance of being overweight/obese. Also, increasing level of education among women of reproductive age in the household was associated with a lower likelihood of the household being undernourished or anaemic, but increasing level of education among reproductive age women in the household was associated with increased likelihood of a household being overweight/obese. However, considering the level of education of women in the reproductive age in the household and household double and triple burden of malnutrition, only tertiary level of education (among women in the reproductive age) was observed to be associated with a lower likelihood of a household having a double or triple burden of malnutrition.Finally, the chances of a household being undernourished decreased in more recent survey years except in 2016, whereas the chances of a household being overweight/obese or anaemic or having a double or triple burden of malnutrition increased in recent survey years.The current study sought to examine the correlates of different classifications of household burden of malnutrition in SSA. To the best of our knowledge, this is the largest analysis examining household covariates of various conditions of malnutrition; undernutrition, overweight/obesity and anaemia and the co-occurrence of these conditions in the same household, using nationally representative data across sub-Saharan African.,40. Our results show that micronutrient deficiency measured as anaemia is the commonest burden of malnutrition among women (15–49 years) and children under 5 in households across SSA. This burden of anaemia corroborates with studies conducted in Arab and Middle East countries,42. Reasons for the high prevalence of anaemia in the SSA region are multifaceted. Besides low intake of iron-rich foods, factors such as inadequate hygiene and sanitary conditions are documented as contributors to anaemia in this region. Additionally, conditions such as glucose-6-phosphate dehydrogenase deficiency, haemoglobinopathies endemic diseases such as malaria and sickle cell all contribute significantly to the regions’ anaemia prevalence–45. The present study reveals that undernutrition occurs in one in two households, while overweight/obesity was present in about one in every four households in SSA. The results of the current study suggest that the prevalence of single conditions of malnutrition is comparatively higher than double and triple burden of malnutrition. However, the level of DBM as found in the current study is comparable to the level in Nepal (6·60 %). This notwithstanding, an earlier study conducted in Bangladesh, Nepal, Pakistan and Myanmar found the level of household DBM to be slightly lower than that of the present study, but the level of TBM as was found in the present study is slightly lower (4·6 %) than what was found in Nepal (7·0 %) by Sunuwar et al..The findings suggest that despite the stereotype image of skeletal children with severe hunger in SSA, the current study like many others, shows that overweight/obesity is also a public health concern in this region. The size of the household on the other hand was associated with a higher likelihood of undernutrition and anaemia as has been found in other studies. These findings are plausible because increasing household size affects access to food such as fruits, vegetables, meat and fish which tend to be relatively more expensive. The absence or reduction of such foods contributes significantly to iron-deficiency, causing anaemia. Household size was, however, found to be associated with a lower likelihood of the household having either an overweight/obese woman or child or both. Other household characteristics such as the type of toilet facility was found to be associated with the household’s likelihood of having either an overweight/obese woman or child and also double and triple burden of malnutrition in the household. The mechanism of impact of type of toilet facility on the household burden of malnutrition as found in the present study could be operating through wealth or socio-economic status. Households with improved toilet facilities tend to be relatively wealthier compared with households with unimproved toilet facilities, and such wealthier households have been found to have higher burden of overweight/obesity, especially among women, and this could be what is driving the household burden of overweight/obesity, double and triple burden of malnutrition as was observed in the present study.In addition to the levels of household burden of malnutrition, which was realised, the results indicate that the prevalence of the various forms of household burden of malnutrition and their underlying household influencing factors are different. For example, whereas increasing age of the household head was associated with a lower likelihood of the household being undernourished, the same variable was associated with a higher likelihood of the household being overweight/obese and anaemic. But unlike the age of the household head, the sex of the head of the household head was not associated with any of the forms of household burden of malnutrition. This is contrary to a study conducted in Indonesia that reported some nutritional inequality among female-headed households. Some of the plausible reasons for this finding are that while rich households may be more food secure,51 and also benefit from a more diverse diet, thus reducing the risk of undernutrition and micronutrient deficiency, rich households are also at a higher risk of overweight/obesity due to consumption of energy-dense foods and lower levels of physical activity. The location of a household, whether rural or urban, was also found to be associated with household burden of malnutrition. Rural households were found to have a lower likelihood of being overweight/obese or anaemic. Contrarily, other studies in some SSA countries, for example Ghana found that rural residence is associated with a high likelihood of micronutrient deficiency. Another study conducted in the Gambia did not find significant difference in anaemia among non-pregnant females by residence. These results do show the possible variability in the conditions contributing to anaemia in the region.In terms of household wealth status, the results indicate that while richer households are less likely to be undernourished or anaemic, they are more likely to be overweight/obese and also, have double burden or triple burden malnutrition conditions. Similar findings have been reported in Nepal where mothers from the richest households were more likely to have double or triple burden of malnutrition, while in Pakistan and Myanmar, Anik and colleagues found that child’s age (24–59 months) was associated with a higher likelihood of the household experiencing a double burden of malnutrition. Additionally, the present study found that child’s age was significantly associated with a higher likelihood of the household being undernourished as was found in Sierra Leone before the Ebola outbreak. The effect of the age of children on the household burden of malnutrition could be a result of child feeding practices especially during complementary feeding and the weaning period. Poor feeding practices, feeding children with poor quality and or unbalanced diets and unhygienic feeding practices in the complementary feeding/weaning period increase the likelihood of undernutrition and micronutrient deficiency among children, and this contributes to the household burden of malnutrition.The present study found that increasing age of children under 5 years was associated with a higher likelihood of household TBM contrary to the findings of Sunuwar and colleagues in Nepal. Increasing age among women was associated with a higher chance of the household experiencing double and triple burden of malnutrition. The higher chance of overweight and obesity among older women in sub-Saharan Africa is one of the possible drivers of the higher likelihood of household DBM and TBM as was found in the present study. Again, being in a marital union (for women of reproductive age) was found to be associated with a higher chance of the household being overweight/obese. This could also be because of the higher likelihood of married/cohabiting women being overweight/obese compared with their counterparts who are not married or in union. The level of education of women in the household also showed expected results. Higher level of education among women in the household was associated with a lower likelihood of the household being undernourished or anaemic on one hand but a higher likelihood of household overweight/obesity on the other hand. This pattern of results is likely being driven by other mechanisms influenced by education. For example, educated women are more likely to be employed and or gain income and thus they can contribute to meeting the food expenditure needs of their household which lowers the risk of food insufficiency thereby reducing the chances of undernutrition while also ensuring that the household consumes a balanced and diversified diet and thereby reducing the chances of micronutrient deficiency. But on the other hand, households with educated women may also be at risk of having overweight/obese individuals because of frequent consumption of high calorie energy-dense foods such as polished rice, sweetened carbonated drinks and high-fat high sugar snacks.Considering the characteristics of reproductive age women who are members of the household, the findings with regard to their age were as expected and similar findings have been found among women in Nepalet al..The findings regarding the year the survey was conducted gives indication of the ongoing nutrition transition in sub-Saharan Africa. The chances of household undernutrition generally decreased in more recent years, whereas the chances of overweight/obesity and anaemia increased in recent years. Again, the chances of double and triple burden of malnutrition were found to increase in more recent years. Changing dietary behaviours from consumption of nutritious staple/traditional diets rich in fibre and complex carbohydrates to the consumption of high calorie, energy-dense, fatty foods and food with simple sugars in recent years could be contributing to the higher likelihood of overweight/obesity and anaemia and the higher risk of double and triple burden of malnutrition in households in SSA. The high prevalence and higher likelihood of anaemia is particularly concerning. Governments of SSA countries and the international community need to pay attention to this as emphasised by Jiwani . These can be achieved through integrated initiatives, policies and programmes involving different sectors such as the various health and agricultural sectors in countries. Thus, working within ‘institutional silos’ should be avoided as much as possible when addressing the double and triple burden of malnutrition.In tackling the double and triple burden of malnutrition, the WHO suggests ‘Double-duty’ actionsThe findings of the current study reveal some important findings about the dynamics between household factors and household burden of malnutrition. The current study is one of the few studies that uses nationally representative data across SSA to investigate correlates of household burden of malnutrition from the perspective of influencing household factors. Other studies have mostly investigated individual-level risk factors while controlling for some household characteristics. The current study is also among the few studies that attempt to investigate the prevalence and influencing factors of double and triple burden of malnutrition at the household level across SSA. The study is, however, challenged by some limitations. For example, it would have been helpful to include dietary diversity at the household level in the analysis but not all countries collected data on this indicator; therefore, household dietary diversity could not be included in the analysis. Including this variable in the analysis if it was available may have given some more insights into the findings of the present study. Another limitation with the current study is the use of anaemia as the only indicator of micronutrient deficiency. It will be helpful for future research to measure other indicators of micronutrient deficiency if such data are available. Additionally, the use of IPUMS data has some limitations due to the differing content of questionnaires used in different countries and the suppression of low-level geographic detail. The latter is, however, done to protect confidentiality of respondents. Additionally, although the DHS to a large extent has consistent variables that are collected across the participating countries, there are some variables that may be missing or collected differently. This presents a situation where the sample (number of respondent) may vary during pooled data analysis as was the case in the present study. These challenges notwithstanding, the current study provides insights into the prevalence and household factors that influence the burden of malnutrition at the household level in sub-Saharan Africa.. Efficiently managing household double and triple burden of malnutrition will require a life-course approach as suggested by Darnton-Hill et al.. This is important because undernutrition among children could result in overweight/obesity in later adult years, and undernourished women are likely to give birth to underweight children who are at risk of becoming overweight/obese in later years. Unfortunately, knowledge of the current scenario of DBM and TBM has not necessarily translated in concrete policy action in some countries. For example, even though the ‘Roadmap for Nutrition in South Africa 2013–2017’ and Ghana’s ‘National Nutrition Policy For Ghana 2013–2017’,60 both acknowledge the presence of both under and overweight/obesity, no clear recommendation is provided towards curbing their co-occurrence in same households. It thus goes without saying that nutrition programming interventions need to address both undernutrition which is dominated by childhood stunting and increasing overweight/obesity among both children and adults and the co-existence of all these conditions in the same household if SSA is to achieve success in combating the burden of malnutrition in the region.The findings of the current study reveal a high prevalence of various forms of household burden of malnutrition particularly the single burden of anaemia, undernutrition and overweight/obesity. The findings further indicate that undernutrition and now overweight/obesity are not the only forms of malnutrition that affect households in SSA. Anaemia is indeed a persistent problem that needs urgent policy attention. Although rapid economic development and urbanisation in the SSA region has created favourable conditions for overweight/obesity, the persistence of poverty and poor access to resources continue to drive the prevalence of anaemia and undernutrition, and the co-existence of extreme spectrums of malnutrition, i.e. double and triple burden of malnutrition in the same household. Though individuals and/or households may respond differently to similar diet and lifestyles, diet quality is a major factor influencing single, double and triple burden of malnutrition


To investigate whether fractal analysis of perfusion differentiates hepatocellular adenoma (HCA) subtypes and hepatocellular carcinoma (HCC) in non-cirrhotic liver by quantifying perfusion chaos using four-dimensional dynamic contrast-enhanced magnetic resonance imaging (4D-DCE-MRI).ex3-HCAs), 27 inflammatory HCAs (I-HCAs), and 16 HCCs. Four-dimensional fractal analysis was applied to arterial, portal venous, and delayed phases of 4D-DCE-MRI and was performed in lesions as well as remote liver tissue. Diagnostic accuracy of fractal analysis was compared to qualitative MRI features alone and their combination using multi-class diagnostic accuracy testing including kappa-statistics and area under the receiver operating characteristic curve (AUC). Fractal analysis allowed quantification of perfusion chaos, which was significantly different between lesion subtypes , except between I-HCA and HCC. Qualitative MRI features alone did not allow reliable differentiation between HCA subtypes and HCC (κ = 0.35). However, combining qualitative MRI features and fractal analysis reliably predicted the histopathological diagnosis (κ = 0.89) and improved differentiation of high-risk lesions  and low-risk lesions  from sensitivity and specificity of 43%  and 47% (CI 32–64%) for qualitative MRI features to 96% (CI 78–100%) and 68% (CI 51–81%), respectively, when adding fractal analysis.A retrospective population of 63 patients  with histopathologically characterized HCA and HCC in non-cirrhotic livers was investigated. Our population consisted of 13 hepatocyte nuclear factor (HNF)-1α-inactivated (H-HCAs), 7 β-catenin-exon-3-mutated (bCombining qualitative MRI features with fractal analysis allows identification of HCA subtypes and HCCs in patients with non-cirrhotic livers and improves differentiation of lesions with high and low risk for malignant transformation.The online version contains supplementary material available at 10.1186/s13244-022-01223-6. Fractal analysis quantifies chaos of perfusion in different hepatocellular adenoma (HCA) subtypes and hepatocellular carcinoma (HCC) in the non-cirrhotic liver using perfusion MRI.Visual analysis of MRI features was not sufficiently reliable to differentiate between HCA subtypes and HCCs in non-cirrhotic livers.Combining fractal analysis of perfusion and qualitative MRI features allowed reliable prediction of the histopathological lesion subtype.Fractal analysis of perfusion improved differentiation of lesions by risk for malignant transformation.ex7/8-HCA), β-catenin-exon-3-mutated HCA (bex3-HCA), sonic hedgehog HCA (shHCA), and unclassified HCA, with two mixed forms derived from I-HCA and the two variants of b-HCA ) and moderate correlation (Spearman’s ex3-HCAs (86%). Overall, combining visual MRI features with fractal analysis achieved high agreement to histopathological reference (κ = 0.91 [CI 0.83–0.98]) and strong correlation .Combining visual MRI features and fractal analysis improved the prediction of the histopathological diagnosis to 13/13 H-HCAs (100%), 13/27 I-HCAs (48%), and 16/16 HCCs (100%), and allowed to correctly predict 6/7 bex3-HCAs) and a low-risk group (H-HCAs and pure I-HCAs) according to their  malignant behavior. As explained in the Methods section, we used an intention-to-diagnose approach to deal with non-diagnostic lesions. Doing so, we found a sensitivity and specificity for identifying high-risk lesions by qualitative MRI features alone of 43% (CI 23–66%) and 47% (CI 32–64%), respectively, with an AUC of 0.55 (CI 0.42–0.68). The combination of qualitative MRI features and fractal analysis achieved 96% (CI 78–100%) sensitivity, 68% (CI 51–81%) specificity, and an AUC of 0.82 (CI 0.73–0.90). This improvement was significant for sensitivity (p = 0.003) and AUC (p = 0.003) but not for specificity (p = 0.3).For differentiating lesion types by clinical relevance, we divided the lesions in our study population into a high-risk group (HCCs and bex3-HCA) from low-risk lesions . Interestingly, fractal analysis revealed a higher perfusion chaos of HCCs in comparison with bex3-HCAs. Therefore, the FD might be an effective imaging biomarker to differentiate those two entities, for which typical imaging features have not yet been established [diff values therefore do not require specific protocol adaptations and do not rely on a specific perfusion model.Among patients with non-cirrhotic livers, we found that fractal analysis is an effective descriptor of perfusion chaos and adds complementary information for differentiating between HCA subtypes and HCC. When typical qualitative MRI features are absent, fractal analysis can significantly improve diagnostic accuracy in differentiating high-risk (HCC, bablished . In our In clinical practice, correct imaging-based subtyping of HCA is challenging  and, altdiff was similar in I-HCA and HCC, which both had highly chaotic perfusion patterns on visual inspection. This observation might be attributable to high vascular density and potentially similar architectural vascular changes due to inflammation or tumor angiogenesis, especially in comparison with benign lesions like bex3-HCA prior to malignant transformation. Indeed, compared to the other subtypes of adenomas like bex3-HCA, I-HCA contains more arteries and dilated sinusoids which are commonly of large size, and HCC is composed of numerous isolated arteries [Fractal analysis allows quantitative assessment of the perfusion pattern, thus providing information on the architecture of the underlying vasculature. Differences in vascular structure have been found between different HCA subtypes . In our arteries , 33. SucSince perfusion is inherently chaotic, an absolute interpretation of the FD can be challenging, especially in the liver, with its unique dual vascular supply by the arterial and portal venous system. In previous studies, quantitative intensity measurement has been standardized to normal liver parenchyma . We adopThis study has limitations: The number of cases included in this retrospective analysis is limited, and no shHCA or b-HCA with confirmed exon7,8-mutation were included. These are two rare subtypes, each accounting for approximately 4% of all HCAs . MoreoveOur results might stimulate further research to monitor potential malignant transformation of lesions in patients managed by watchful waiting. Fractal analysis might constitute an indicator for such malignant transformation and might be useful in identifying lesions that require definitive surgical treatment versus lesions that only require follow-up. Moreover, it might be interesting to investigate whether our results could also help in predicting major complications, e.g., hemorrhage or rupture, which are more common and potentially life-threatening complications in HCAs . As a quIn conclusion, our study indicates that the chaos of perfusion differs between HCA subtypes and between HCA and HCC in the non-cirrhotic liver. Fractal analysis can be used to quantify these differences using three-phasic 4D DCE-MRI. According to our hypothesis, chaos of the perfusion pattern is strongly related to the organization of the underlying vascular structure, which is assumed to differ between the tumor entities and subtypes analyzed in our study.Additional file 1. Image Preprocessing.


In this paper, we propose a probabilistic channel model with correlated insertion and deletion (CID) errors to capture the data dependence applicable to the bit-patterned media recording (BPMR) system. We also investigate the error performance and decoding complexity of a concatenated LDPC-marker code over the CID channel. Furthermore, we modify the forward backward decoding algorithm to make it suitable for the CID channel, and elaborate it based on a two-dimensional state transition diagram. Compared with the conventional marker coding scheme dealing with random errors, the concatenated LDPC-marker code takes into account the dependence between synchronization errors, improves the error performance, and reduces the decoding complexity. The BER performance of the concatenated LDPC-marker code is improved by more than 50% on average, and the decoding time is reduced by nearly 35% when the LDPC code ( Channels impaired by insertion, deletion and substitution errors were first considered in 1961 , image wMany coding schemes have been proposed for channels impaired by random insertion, deletion and substitution errors in the past few decades . SynchroHowever, the concatenated coding schemes mentioned above are developed for channels with random independent errors. Very few papers focus on codes correcting correlated errors. In fact, correlated insertion and deletion errors exist in some practical applications, such as BPMR systems. In BPMR, deletions and insertions often occur in pairs  . In partSeveral channel models suitable for the writing process of BPMR have been proposed. Dependence of written-in errors was considered by Mazumdar et al. in , but theIn BPMR writing process, 1) a deletion is followed by an insertion in a latter position, and vice-versa; 2) the subsequent synchronization error probability is more likely to occur at the position closer to the preceding one and decreases with the distance. As far as we know, no channel models have been proposed for BPMR systems that considers both of the above error statistics. For the above reasons, we propose a more accurate channel model that takes into account all error statistics in BPMR writing process.In this paper, we first propose a probabilistic channel model with correlated insertion and deletion errors, in addition to substitution errors. The channel model captures, for example, the data dependence adapted to the write channel in BPMR more accurately. Then, we modify the forward-backward algorithm to make it suitable for the proposed channel. Finally, we compare the error performance of the concatenated LDPC-marker coding scheme with the conventional marker coding scheme without considering the dependency between synchronization errors over the proposed channel. The paper is organized as follows. Sect. II introduces the proposed channel model, the concatenated LDPC-marker code, and the encoding and decoding steps. Sect. III describes the details of the modified forward-backward algorithm based on a two-dimensional transition diagram. Sect. IV presents simulation results and discussion. Concluding remarks and future work are given in Sect. V.This section starts with a binary channel with random errors and the proposed probabilistic channel model with correlated insertion and deletion errors, followed by a description of the encoding and decoding of the concatenated LDPC-marker code.xk, three possible events may occur: (1) xk is deleted with probability pd; (2) one more bit is transmitted before xk with probability pi; (3) xk is transmitted with probability pt = 1 − pd − pi. Moreover, the transmitted bit may be substituted with probability ps. The operation repeats until all bits are sent. Insertions and deletions are random without correlation in this channel.A channel with random independent insertion, deletion and substitution errors proposed by Davey and MacKay  is depicHere, we propose a probabilistic channel with correlated insertion and deletion (CID) errors, i.e., an insertion and a deletion occur in pairs while substitution errors occur randomly within a sequence. Such a channel is referred to as a correlated insertion/deletion (CID) channel.a1 < b1 < a2 < b2 < a3 < b3 < ⋯. We also call n = 1, 2, …) a synchronization error bit pair.Given a transmitted sequence The characteristics of the proposed probabilistic channel model are as follows.The synchronization error probability of We assume l between l increases.The synchronization error probability of l, we assume that l = 1, 2, …) forms a geometric progression with a common ratio of r < 1, i.e.,A is a constant. After a synchronization error has occurred to xan+ l. Moreover, they are given by Eqs  l = 1, , … formsn by Eqs . The proNm are inserted periodically every Nc LDPC code bits. For an LDPC code with length N, the regularly inserted markers divide the LDPC code into N/Nc segments (assuming N/Nc is an integer). Each of the segment consists of Nc + Nm bits where the first Nm bits are the marker bits and the last Nc bits are the LDPC code bits. The content and position of the periodical markers in the transmitted sequence are known to and used by the receiver to maintain synchronization. The encoded sequence after the two encoding steps is ready to be transmitted through the channel. The code rate of the concatenated code is R = RC ⋅ RM, where RC and The presented scheme consists of an outer LDPC code and an inner marker code, as shown in xi ∈ {0, 1} for i = 1, 2, …, t and yi ∈ {0, 1} for i = 1, 2, …, r as the transmitted and the received sequences, respectively. At the receiver, the corrupted sequence xk ∈ {0, 1} and k = 1, 2, …, t. To derive the likelihood We denote lgorithm , which wH in which the number of non-zero entries is small. We apply the sum-product decoding algorithm  to decode the LDPC code by iteratively passing updated LLR messages along the edges between variable nodes and check nodes in the Tanner graph corresponding to H. At the end of each iteration, the updated a posteriori LLR for each transmitted bit is calculated and an estimated codeword is obtained by making hard decisions based on the LLRs. The LDPC decoder subsequently checks whether the estimated codeword satisfies all check equations. The codeword is successfully decoded if all check equations are satisfied; otherwise, the iteration continues. If the maximum number of iterations is reached and not all check equations are satisfied, the decoding fails.LDPC code is a linear block code with a sparse parity-check matrix In this section, we modify the forward-backward algorithm to make it suitable for the proposed CID channel, taking into account the correlated insertion and deletion errors. We further elaborate a computationally efficient marker decoding algorithm based on a two-dimensional state transition diagram. Finally, the inner marker decoder implements the modified FB algorithm to compute the LLR to initialize the outer LDPC decoder.S0,0 as the initial state when the transmission begins; and St,r as the end state when t bits have been sent and r bits have been received. We also define an intermediate state Si,j when i bits  have been sent and j bits  have been received. State Si,j may transit to Si+1,j, Si+1,j+1 and Si+1,j+2 if there is a deletion error, no deletion/insertion error, and an insertion error, respectively, for the transmitted bit xi+1. The transitions are illustrated in i − j = 1) and the upper boundary (j − i = 1).We define xi is either an LDPC code bit or a marker bit. For an LDPC code bit xi, Pr(xi = 0) = Pr(xi = 1) = 0.5 because no information about an LDPC code bit xi is provided to the decoder and the receiver does not know the value of xi. However, when xi is a bit from the marker, Pr(xi) is a determined value, i.e., (a) Pr(xi = 0) = 0 and Pr(xi = 1) = 1; or (b) Pr(xi = 0) = 1 and Pr(xi = 1) = 0. The reason is that the exact value and position of a marker bit xi are accurately known to the receiver.A transmitted bit T as the transmission probability that xi is transmitted (with/without insertion) and the corresponding received bit is yj, i.e.,C denotes the probability that the transmitted bit xi and the corresponding received bit yj have or do not have the same value. If xi = yj, xi has been transmitted without any substitution error and thus C = 1 − ps; otherwise, xi is substituted and C = ps. Thus, we haveWe define αi,j is the joint probability that i bits are transmitted and the j bits S0,0 to Si,j. The forward quantity αi,j is given byxi is transmitted over the CID channel. According to the relationship between i and j and the location of the previous state, three scenarios are to be considered in order to calculate αi,j as shown in The forward quantity Case 1: Si,jis located on the lower boundary wheni − j = 1 and it can be reached fromSi−1,j−1andSi−1,j, as shown inCase 2: Si,jis located on the diagonal wheni − j = 0 and it can be reached fromSi−1,j−2, Si−1,j−1andSi−1,j, as shown inCase 3: Si,jis located on the upper boundary whenj − i = 1 and it can be reached from eitherSi−1,j−2orSi−1,j−1, as shown inα0,0 = 1 and α0,1 = 0, all other values of αi,j within the boundaries in In summary, given the initial conditions βi,j denotes the probability that the remaining r−j received bits are Si,j has occurred. The backward quantity βi,j is therefore denoted byxi+1 is transmitted through CID channel. According to the relationship between i and j, three scenarios are to be considered in order to calculate βi,j as shown in Si,j.Similarly, the backward quantity Case 1: Si,jis located on the lower boundary wheni − j = 1 and it can transit toSi+1,j+1orSi+1,j+2, as shown inCase 2: Si,jis located on the diagonal wheni − j = 0 and it can transit toSi+1,j, Si+1,j+1orSi+1,j+2, as shown inCase 3: Si,jis located on the upper boundary whenj − i = 1 and it can transit toSi+1,jorSi+1,j+1, as shown inβt,r = 1 and βt,r−1 = 0, all other values of βi,j within the boundaries in In summary, given the initial conditions αi,j and βi,j under three cases, i.e., xi is deleted; xi is transmitted without deletion or insertion error; and xi suffers from an insertion error. They are derived as follows.The likelihoods Case 1: Only two scenarios are possible whenxiis deleted.Case 2: Three scenarios are possible whenxiis transmitted without synchronization errors.Case 3: Only two scenarios are possible whenxiis transmitted with an insertion error.xi ∈ {0, 1}. The LLRs are subsequently computed using Because all the cases are independent, the overall m of Eqs , 17) an anp LDPC code [Nc and Nm are given.Simulations are conducted to investigate the error performance of the concatenated LDPC-marker code over the CID channel. We have implemented the simulation using Matlab program under the Windows operating system and the simulation is carried out as follows. A random sequence of DPC code  with rata posteriori LLR for each transmitted bit and make a hard decision on the LLRs to estimate a decoded codeword. The LDPC decoder immediately checks whether the estimated codeword satisfies all check equations. The block is decoded successfully if it satisfies all check equations; otherwise, the iteration continues. In our simulations, the maximum number of iterations is set to 60. If the decoded codeword cannot satisfy all check equations after the maximum number of iterations, the decoding fails. We perform the decoding procedure and count the number of decoded bits and blocks in error. The bit error rate (BER) and block error rate (BLER) are used as metrics to evaluate the error performance of the concatenated LDPC-marker code.The received corrupted sequence is first decoded by the inner marker decoder. The inner marker decoder uses the modified forward-backward algorithm described in Sect. IV to derive the LLR of each LDPC code bit. All LLRs are sent to the outer LDPC decoder. The LDPC decoder further decodes the codeword through the sum-product algorithm. At the end of each iteration, the LDPC decoder calculates the updated Nm = 2 are inserted at the beginning of each LDPC codeword, and also periodically every Nc = 18 LDPC code bits. In other words, each marker is followed by 18 LDPC code bits, except the last marker which is followed only by 3 code bits. The total length of the transmitted sequence is 5023 bits per block and the overall code rate is R = 3552/5023 = 0.71. For this simulation, we consider pi = pd and set A = r = 0.5 in pi, pd and ps increase. We first investigate the case when there are only insertion and deletion errors, i.e., ps = 0. The BER of the concatenated LDPC-marker code can be as low as 2 × 10−6 when pi = pd = 2 × 10−3. The BER of the concatenated LDPC-marker code increases as pi and pd increase. For example, the BER of the concatenated LDPC-marker code increases from 2 × 10−6 to 10−3 when pi and pd increase from 2 × 10−3 to 5 × 10−3 in −4 when pi = pd = 2 × 10−3. The BLER of the concatenated LDPC-marker code also increases as pi and pd increase. For example, the BLER of the concatenated LDPC-marker code increases from 2 × 10−4 to 0.12 when pi and pd increase from 2 × 10−3 to 5 × 10−3 as shown in In the first set of simulations, regular markers ‘10’ of length ps. The simulation results show that the decoder can correctly decode the corrupted block when ps is relatively low. For example, when pi = pd = 3 × 10−3 and ps = 0.01, BER and BLER are as low as 1.7 × 10−4 and 8 × 10−3, respectively. However, more bits suffer from substitution errors as ps increases and hence both BER and BLER increases. For example, the BLER increases rapidly from 2 × 10−4 to 1.2 × 10−2 when ps increases from 0 to 0.02 (pi = pd = 2 × 10−3). The corrupted block cannot be decoded at a higher substitution error rate because the number of substitution errors exceeds the correction capability of the LDPC code.Furthermore, we investigate and compare the error performance in terms of BER and BLER with different Nm on the error performance of the concatenated code. We fix Nc = 18 and use Nm = 2, 3, 4. The markers used are ‘10’, ‘101’ and ‘1010’ while the corresponding overall code rates are 0.71, 0.67 and 0.64, respectively. For this simulation, we set A = r = 0.5 in Nm is shown in Nc is fixed, the BLER decreases as the marker length Nm increases. For example, when pd = pi = 4 × 10−3 and ps = 0.01, the BLER decreases from 8 × 10−2 (Nm = 2) to 2 × 10−2 (Nm = 4). When pd = pi = 3 × 10−3 and ps = 0, the BLER decreases from 7 × 10−4 (Nm = 3) to 4.5 × 10−4 (Nm = 4). In other words, the error performance of the concatenated code is improved by increasing the marker length Nm. However, the code rate of the concatenated code is decreased as the marker length Nm increases. We also notice that the error performance of the concatenated code in terms of BLER is seriously affected by ps. For example, when pi = pd = 3 × 10−3, the BLER for Nm = 4 increases by about 50 times, rapidly from 4.5 × 10−4 (ps = 0) to 2.1 × 10−2 (ps = 0.02). The results show that even though markers help to maintain synchronization, corrupted blocks cannot be corrected due to a large number of substitution errors.We first investigate the marker length Nc on the error performance of the concatenated code. We fix Nm = 2 and use Nc = 18, 24, 30. The corresponding overall code rates are 0.71, 0.73 and 0.74, respectively. The marker interval Nc is related to the number of markers. A larger marker interval means fewer inserted markers in a block. For this simulation, we set A = r = 0.5 in Nc under different channel parameters. It can be observed that the BLER error performance is improved with a smaller marker interval or more markers. For example, when pd = pi = 3 × 10−3 and ps = 0, the BLER increases from 2.1 × 10−3 (Nc = 24) to 4 × 10−3 (Nc = 30). When pd = pi = 2.5 × 10−3 and ps = 0.01, the BLER increases from 3 × 10−3 (Nc = 18) to 5.8 × 10−3 (Nc = 24). In other words, reducing the marker interval or inserting more markers in a block improves the error performance of the concatenated LDPC-marker code.We also study the effect of marker interval Nm, smaller marker interval Nc and more markers have a better synchronization capability and hence error performance. Although increasing Nm and/or reducing Nc improve the error performance of the concatenated code, the information transmission efficiency and code rate is reduced.From the simulation results in Figs A = 0.5 and r = 1 in Nm = 2 and Nc = 18 is adopted so that both codes have the same code rate 0.71 for a fair comparison. The BLER curves of the concatenated LDPC-marker code over the CID channel and the BLER curve with the best performance in [ps = 0.01. This improvement is more significant with the increase of insertion and deletion error rates. For example, when pd = pi = 5 × 10−3 and ps = 0.01, the BER of the concatenated code is 2.8 × 10−3 while the BER of the best code in [−2. We also observe that the concatenated code at ps = 0.02 even performs better than the best code in [ps = 0.01 when pd and pi are greater than 3.3 × 10−3. This proves that the concatenated LDPC-marker code has a better resistance to substitution errors. Compared with [Simulations are further carried out to compare the error performance of the concatenated LDPC-marker code with the result in . In orderates in  for subsmance in  under thmance in  when ps  code in  is more  code in  at ps = red with , the CIDNm = 2 and use Nc = 18, 24, 30. The corresponding overall code rates are 0.71, 0.73 and 0.74, respectively. For this simulation, we consider pi = pd, ps = 0.01 and set A = r = 0.5 in We further investigate and compare the error performance of the concatenated LDPC-marker code considering correlated synchronization errors with the conventional marker coding scheme (MCS)  without The simulation result shows that the concatenated LDPC-marker code produces a lower BER/BLER error rate than the conventional MCS over the CID channel. The improvement is intuitive and can be explained as follows. The conventional MCS assumes that insertion, deletion and substitution errors occur randomly without correlation, and it does not consider the dependency between the synchronization errors in the CID channel. On the contrary, the concatenated LDPC-marker code takes into account the correlation to compute LLRs by means of the modified forward-backward algorithm. As a result, LLRs provided by the inner decoder of the concatenated LDPC-marker code are more accurate. In addition to error performance, we compare the decoding complexity of the two coding schemes. Compared with the MCS, the decoding time of the concatenated LDPC-marker code is greatly reduced by 35% on average for each BLER curve in M-ary data transmission and different LDPC codes over the CID channel.In this paper, we have proposed a probabilistic channel model suitable for BPMR systems with frequent correlated insertion/deletion errors. We have further modified the forward-backward algorithm and investigated the error performance of a concatenated code over this channel. The simulation results show that the inner marker code can effectively maintain synchronization, while the outer LDPC code can provide sufficient error correction capability for the BPMR system. The error performance can be further improved when the marker interval is reduced and/or more markers are inserted in the transmitted sequence. The simulation result shows that the concatenated LDPC-marker code performs much better than the code in . The imp


In the Netherlands, all women aged 30–60 years are invited to participate in the national cervical cancer screening programme, which is aimed at early detection and treatment of precancerous lesions. One fourth of the Dutch population has a migration background, with Turkish and Moroccan immigrants being the largest immigrant populations. Turkish‐ and Moroccan‐Dutch women show lower screening participation rates and a higher incidence of cervical cancer, compared to native Dutch women. Since current information materials are not tailored to these women's needs, we developed a short culturally sensitive educational video to facilitate informed decision‐making for cervical cancer screening among Turkish‐ and Moroccan‐Dutch women. This article describes the development process of this video and the lessons learned.Using the Entertainment–Education communication strategy, we collaborated with an interdisciplinary team of Turkish‐ and Moroccan‐Dutch women, researchers, public health experts, and creative media professionals. We developed the video following the different stages of the Media Mapping model: Orientation, Crystallization, Design/Production, Implementation, and Dissemination. Each stage is described in the paper.The video was developed in Moroccan‐Arabic, ‐Berber and Turkish, and emphasized three main themes: (1) more certainty about having cervical (pre)cancer and the possibility to prevent treatment, surgery, or premature death, and because of this, being there for the children, (2) according to the Islam, a woman should take good care of her health, and (3) anxiety, shame, and privacy.A short culturally sensitive educational video, delivered as part of a larger intervention together with the current information brochure, was developed based on theory and grounded in the needs of Turkish‐ and Moroccan‐Dutch women. The value and effectiveness of this intervention to facilitate informed cervical cancer screening decisions are evaluated in a randomised controlled trial.We collaborated with Turkish‐ and Moroccan‐Dutch women during the development process of a short culturally sensitive educational video. Turkish‐ and Moroccan‐Dutch women were also invited to watch the raw footage to verify whether the content and presentation matched their needs and requirements. Although CC screening has led to a substantial decline in both early‐ and late‐stage CC,Based on the national screening programme, regional screening organizations invite women aged 30–60 years every 5 years by sending them a Dutch invitation letter and information brochure to their home addresses. This information brochure is also available in other languages , but can only be found online (via the URL provided in the Dutch invitation letter). Other additional information materials  can also be found online.We found earlier that the current invitation letter and information brochure are not tailored to the needs of Turkish‐ and Moroccan‐Dutch women because of a lack of information on the practical, emotional, cultural, and religious aspects of CC screening.To create the video, an interdisciplinary team was formed consisting of members of the targeted audiences , researchers, public health experts, and creative media professionals. We will illustrate this collaborative process following the different stages of the Media Mapping model of the Center for Media and Health22.1The current strategy in the Netherlands is to encourage women to gather information about both the advantages and disadvantages of CC screening, to ultimately make an informed decision regarding their participation. Participation in CC screening is entirely voluntary.In the Netherlands, 24.4% of the population has a migration background, which includes both individuals who were born abroad (further referred to as first‐generation immigrants) and those who have at least one parent born abroad (further referred to as second‐generation immigrants).Steens et al.Multiple factors can play a role in women's decision‐making process regarding cancer screening, such as lack of awareness and knowledge, organizational issues, and sociocultural aspects.Since the current invitation letter and information brochure include mostly factual medical information, practical, emotional, cultural, and religious aspects need to be added. Moreover, Turkish‐ and Moroccan‐Dutch women often indicated that they did not (thoroughly) read the invitation letter and information brochure, or simply could not understand these materials due to a lack of a good command of the Dutch language.Therefore, in accordance with the ELM, and to further stimulate the informed decision‐making for CC screening among Turkish‐ and Moroccan‐Dutch women, we developed a short culturally sensitive educational video in the women's own languages  to complement the currently used information brochure. The narrative in this video focused on practical, emotional, cultural, and religious aspects of CC screening.2.1.1To develop a short culturally sensitive educational video to facilitate informed decision‐making, we made use of the Entertainment–Education (EE) communication strategy.2.2Upon completion of the orientation phase, we approached several video production companies. We selected the company called Zouka Media, who had proven experience and expertise in producing videos for and by Turkish‐ and Moroccan‐Dutch women. The ideas of the researchers and Zouka Media aligned well in approaching and informing these women through a short culturally sensitive educational video , and Zouka Media showed great willingness to work in an interdisciplinary team. Subsequently, a contract was negotiated between the partners.We conducted formative research as input for the development of the briefing document. We held six focus group discussions among 24 Turkish‐ and 20 Moroccan‐Dutch women, during which seven main themes emerged.Thereafter, an EE team was formed, consisting of representatives of the targeted audiences, the health communication field, and the media field. In the end, the team consisted of eight Turkish‐ and Moroccan‐Dutch women (who later figured as the main characters in the videos), a health communication expert, three cancer screening and public health experts , and a video producer and director .We developed the video in three languages, namely, Turkish, Moroccan‐Arabic, and ‐Berber . Depending on the age, educational level, and migration generation, Moroccans in the Netherlands generally speak Dutch, Moroccan‐Arabic, and/or ‐Berber. Since Berber languages are for them solely speaking languages, Moroccan‐Berber women with a limited command of the Dutch language will have difficulties with reading the Dutch information brochure. They will, however, be able to watch the Moroccan‐Berber video. The same holds for Moroccan women who speak solely Moroccan‐Arabic and Turkish women; they are able to watch the Moroccan‐Arabic and Turkish video, respectively.33.1We identified four relevant determinants and decided to choose for three main themes, since shame and privacy  could easily be discussed in the video jointly. As a result, the short video emphasized the following themes: (1) ‘more certainty about having cervical (pre)cancer and the possibility to prevent treatment, surgery, or premature death, and because of this, being there for the children’, (2) ‘according to the Islam, a woman should take good care of her health’, and (3) ‘anxiety, shame, and privacy’. To facilitate informed decision‐making, it was important to ensure balanced content in terms of the potential benefits and adverse effects of CC screening. We also wanted to emphasise the ease and reliability of self‐sampling, as since 2017, women are able to participate in CC screening by collecting a sample by themselves . As many women indicated not having heard of self‐sampling before,Thereafter, we incorporated two main themes regarding self‐sampling. The first theme was ‘it is easy and not painful to perform self‐sampling’. This was incorporated into the script: ‘I also did it [self‐sampling] at home. It was so easy. It was done in a heartbeat’. The second theme was ‘trust in oneself to correctly perform self‐sampling and trust in the test result’. This was illustrated in the script by one of the actresses saying: ‘Did you know that you can also request a self‐sampling kit? Then you can do it at home without someone else being around. The doctor told me that it is just as reliable as the one performed by the doctor’. In Table Because of the respective age range of 30–60 years, we decided to cast three semi‐professional actresses aged 30, 40, and 50 years approximately. We chose to work with semi‐professional actresses to facilitate a natural look and feel of the video, and also due to our time frame and budget. The youngest actress (aged approximately 30 years) would be the doubting character: the one who was not sure what to decide, since she received the invite to participate in CC screening for the first time. The oldest actress (aged approximately 50 years) would represent the positive role model; she is the most experienced one, as she had already participated in CC screening a couple of times. The actress aged approximately 40 years would represent the negative role model.Since nonparticipation can also be an outcome of an informed decision, we decided that the video would end with the character in doubt saying that she will search for more information to make her decision. The goal of the short video is to stimulate women to make an informed decision by searching for information or talking about the subject with others or the general practitioner. The pay‐off, therefore, included ‘Get well informed. Talk about it with a friend or call your general practitioner. Would you like to know more? Go to…’.We instructed the actresses to act as close friends with whom you can discuss this (intimate) subject, since we know that close friends can act as emotional support in stimulating someone to take the last steps in going to the general practitioner when the CC screening procedure is regarded as scary.After having multiple brainstorming sessions with the EE team and the research team to share professional knowledge as input for the video script, we started the production. Because of the different languages, we worked with three different main characters per video. One of the main characters was a Moroccan woman who spoke both Moroccan‐Arabic and ‐Berber and played a main character in both the Moroccan‐Arabic and ‐Berber versions of the video. Each team of actresses had two sessions before the shooting day with a health communication professional and two creative media professionals to become familiar with the Dutch script. During the first session, we discussed the goal of the video, how they were expected to interact with each other, how to translate some words used in the script, and what they were expected to wear during the shooting day . At the end of this first session, we asked the three teams of actresses to practise and rehearse with each other and play out the script during the second session. During this second session, the two Moroccan teams performed the storyline very well and were given only small additional comments for the shooting day. Unfortunately, the Turkish team had insufficient preparation time due to illness in the team and scheduling difficulties and proved to be not well adjusted to each other during the performance. They were, therefore, asked to meet  again to become familiar with the script and practice the lines and interactions with each other. To help the team do this, one of the creative media professionals offered to be present during this practice session for guidance and support.Unfortunately, because of lockdown measures to control the COVID‐19 pandemic, the initially planned shooting days March 2020) were cancelled. After these measures were lifted, we held two days of shooting under strict restrictions in June 2020  to provide feedback. We asked them for detailed comments and suggestions on its content and presentation, and to assess its understandability and cultural appropriateness. Although their feedback was overall positive, the following changes were suggested: (1) to add culturally appropriate background music, (2) to add certain shots, delete redundant information, shorten the video , or replace certain shots , (3) to speed up the Turkish conversation in the editing, and (4) to overlay audio records in the pay‐off of the video.https://youtu.be/e8m3vz7OHz0 (Turkish), https://youtu.be/QMWwWc4gS4o (Moroccan‐Arabic), and https://youtu.be/VP8Gl2Na4nI (Moroccan‐Berber). An overall making‐of video (in Dutch) can be found via https://youtu.be/uwq1yhRmKV4.After three editing rounds, three short videos (of 3–4 min) were delivered in July 2020. Each can be found through 3.2We studied the video's effectiveness on the women's informed decision‐making through a two‐arm randomised controlled trial (RCT) . In this trial, respondents either received the current Dutch information brochure  (control condition), or this brochure combined with our short video (intervention condition). We were particularly interested in finding out whether a combination of an information brochure (informative approach) and a video (affective approach) would better support the informed decision‐making regarding CC screening participation among Turkish‐ and Moroccan‐Dutch women. The manuscript including the results of this trial is currently in press.Initial respondents were recruited via several social media platforms and invited to complete an online questionnaire. Following respondent‐driven sampling, respondents were asked to recruit a number of peers from their social network to complete the same questionnaire. Respondents were asked several questions on sociodemographic characteristics and informed decision‐making. Subsequently, respondents were randomised to one of the two conditions . Respondents in both the intervention and control arms were asked to study the brochure that was visualised using an image per page. The 20 images could be studied through a ‘slider’ on our questionnaire webpage. Moroccan women in the intervention arm could thereafter indicate which language they preferred: Moroccan‐Arabic or ‐Berber. By clicking ‘Next’, a YouTube video in the preferred language could be played . For Turkish women, a YouTube video in Turkish was presented. After completing one of the two conditions, questions on informed decision‐making were asked again. The final sample of this trial, focusing on the effectiveness of the video on informed decision‐making, included 686 Turkish‐ and 878 Moroccan‐Dutch women. Of this sample, 793 were randomised to the control group (350 Turkish and 443 Moroccan) and 771 to the intervention group (336 Turkish and 435 Moroccan).Respondents in the intervention arm were also asked what they thought about the video.Overall, most women (both Turkish and Moroccan) scored the video as entertaining, informative, clear, and good.In the Turkish video, the older actress was portrayed without a headscarf  and she was coincidentally the positive role model with the most CC screening experience and knowledge. Less than five Turkish respondents found the video offensive to women wearing headscarves, of whom one of them said: ‘The framing where the woman without a headscarf explains everything to the young ignorant women with headscarves is biased and derogatory’.The distribution of the role models was solely based on the actresses' age and we did not take their physical appearance  into account. The acting skills in the Turkish video also had a lower quality than in the Moroccan video. Whether and how these characteristics may affect the video's effectiveness on informed decision‐making are evaluated in our RCT.3.3After the end of the trial, the three short culturally sensitive educational videos were made publicly available on the website of the National Institute for Public Health and the Environment.The videos have also been distributed via the Dutch expertise centre called Pharos. Pharos has ample experience with adapting and disseminating health‐promoting materials among immigrants in the Netherlands. The videos can be found on the Pharos website4In this article, we describe the development of a short culturally sensitive educational video for Turkish and Moroccan women in the Netherlands. This video (affective approach), together with the current Dutch information brochure (informative approach), aims to facilitate informed CC screening decisions among Turkish‐ and Moroccan‐Dutch women. In agreement with earlier calls for full disclosure of intervention development and content,Our participatory EE strategy using the Media Mapping model provides a framework that is both grounded in theory and practice, and involved both members of the intended audiences and various experts. Both the EE strategy and the Media Mapping model proved to be valuable tools to guide the development of a short culturally sensitive educational video.We, therefore, recommend designing and developing such an intervention in a systematic manner  with an interdisciplinary team of members of the targeted audiences, researchers, public health experts, and creative media professionals to ensure the quality and cultural appropriateness of such an intervention.During this intervention development process, we have learned a few important lessons.First, although Turkish‐ and Moroccan‐Dutch women were closely involved in the development process, comments were made by less than five Turkish respondents about specific role models wearing a headscarf or not. As described earlier, in the Turkish video, the older actress was a woman who was portrayed without a headscarf and she was the positive role model with the most CC screening experience and knowledge. We based the distribution of the role models solely on the actresses' age. We used age as an indicator for the number of times invited for screening, and thus, the number of times that a decision had to be made. The more times invited, the more a woman may have read, talked, or thought about or have experiences with the screening. In the future, in addition to age, one's physical appearance  should be thoroughly considered when assigning role models to minimise stereotyping as much as possible. It is important to note, however, that it is very challenging to develop a single video tailored to the needs of a diverse range of individuals . Having said this, efforts should be made to ensure content and image appropriateness for the majority of the targeted audience.Second, and in line with the previous lesson, due to costs, we could only develop a single video (in three different languages), while a broad age range of 30–60 years might require multiple videos, as women in this age group differ greatly in sociodemographic characteristics, such as Dutch language proficiency, educational level, and migration generation. During our previous studies in this project (on which we based the content of the video), we included mostly first‐generation immigrant women aged 46–60 years with a low or medium educational level who came together at community venues.Third, because of our affective approach, the idea was to portray the characters in the video as close friends who talk about intimate matters and give each other advice and emotional support. Because of the COVID‐19‐related restrictions during the shooting days (keeping 1.5 m distance), the three actresses were, however, not able to act as close friends. The actresses could not sit close to each other and could not touch, hug, or kiss each other. We think that this explains why some of the respondents could not imagine that such a conversation would take place in real life. The actresses might have looked like three random strangers, which makes it indeed unlikely that they would discuss such an (intimate) subject with each other.Fourth, the acting skills in the Turkish video had a lower quality than in the Moroccan video caused by insufficient preparation time to feel comfortable acting with each other, as we already observed during our second session with the actresses before the shooting day. Although we kindly asked the Turkish actresses after the second session to put in more time and effort to get a smooth storyline on the shooting day, it remained difficult for them to remember the lines and act naturally. A great advantage in the Moroccan teams of actresses was that they already knew each other . We, therefore, advise allowing for sufficient time to practise acting with each other, especially if actresses do not already know each other.Furthermore, differences in work culture, expectations, and perspectives between representatives of the health communication field and the media field can result in misunderstandings and challenges in combining and balancing entertainment and education. To avoid misunderstandings, we invited all team members to articulate their ideas and views and explain their importance and relevance for the final product. As both fields  are responsible for a balanced mixture of entertainment and education, we made agreements on the roles and responsibilities of both fields, in each stage of the development process. We invested time to create mutual understanding and to reach consensus about the final product's form, content, and presentation.Finally, the approved original script may change due to technical or practical production matters , casting, and costs. As an example, due to the restrictions on the filming location, we were not able to visualise a safe nor homely environment in which close friends discuss intimate subjects, such as cancer and the smear test performed by the general practitioner. Time to prepare the shooting days was also limited, since we had to wait for COVID‐19‐related measures to be lifted and quickly plan the shooting days due to the upcoming summer break and other upcoming film projects of the video producer. Such adjustments need to be discussed, agreed upon, and made during the ongoing production process, keeping in mind that, in culturally sensitive educational videos, alterations might have a stronger effect on the impact, than in written factual information provision.5In the Netherlands, women aged 30–60 years are invited to participate in a free‐of‐charge national CC screening programme, but Turkish‐ and Moroccan‐Dutch women show lower screening participation rates and a higher incidence of CC, compared to native Dutch women. The current information materials are not tailored to these women's needs, since there is a lack of information on the practical, emotional, cultural, and religious aspects of CC screening.Conceptualised and supervised the project: Nora Hamdiui, Mart L. Stein, Jim E. van Steenbergen, Maria E. T. C. van den Muijsenbergh, Aura Timen. Developed and tested the short culturally sensitive educational video: Nora Hamdiui, Martine P. A. Bouman, Damla Keskin, Amina Afrian. Wrote the first version of the manuscript: Nora Hamdiui. Critically reviewed and substantively revised the manuscript multiple times: Nora Hamdiui, Martine P. A. Bouman, Mart L. Stein, Rik Crutzen, Damla Keskin, Amina Afrian, Jim E. van Steenbergen, Maria E. T. C. van den Muijsenbergh, Aura Timen. All authors read and approved the final manuscript.NoneSupporting information.Click here for additional data file.


Video watermarking is an important means of video and multimedia copyright protection, but the current watermarking algorithm is difficult to ensure high robustness under various attacks. In this paper, a video watermarking algorithm based on NSCT, pseudo 3D-DCT and NMF has been proposed. Combined with NSCT, 3D-DCT and NMF, the algorithm embeds the encrypted QR code copyright watermark into the NMF base matrix to improve the anti-attack ability of the watermark under the condition of invisibility. The experimental results show that the algorithm ensures the invisibility of the watermark with a high signal-to-noise ratio of the video, and meanwhile has high ability and robustness against common single and combined attacks, such as filtering, noise, compression, shear, rotation and so on. The issue that the video watermarking algorithm has poor resistance to various attacks, especially the shearing attack, has been solved in this paper; thus, it can be used for digital multimedia video copyright protection. In recent years, the number of online videos has escalated, and it is very easy to publish and obtain video resources. The ensuing digital video copyright issues and data security issues frequently occur, and illegal intruders use modern technical means to arbitrarily access, copy, modify and disseminate media files, seriously threatening the legitimate interests of copyright holders, and even causing harm to personal and property safety ,2,3. As At present, the research of digital watermarking technology for video is mainly based on spatial domain ,5,6, comTransform domain video watermarking is also an important branch of video experiments, and has a vast range of transform and decomposition methods that can be applied, and that have better robustness. This kind of algorithm is designed to embed and extract the watermark in the transform domain. DWT (Discrete Wavelet Transform) , DCT  to obtain the spectral distribution of the video in space and time. Fu et al. embedded the watermark into the feature matrix after 3D-DCT, and the experimental data show that the 3D-DCT coefficient is more suitable for watermark embedding than the 2D-DCT coefficient.DCT is a commonly used transformation in digital watermarking, but most of the images used 2D-DCT to obtain their spectrum. Using 3D-DCT, the video stream can be processed using DCT along the three dimensions Divide every four keyframes into a group, where each frame is a sub-block of (2)The DC coefficients of sub-blocks at the same position in each group are connected along the time axis to form a sequence, upon which 1D-DCT is carried out. The result is the pseudo 3D-DCT coefficient.The pseudo 3D-DCT principle is shown in B of M × N can be decomposed into the product of the basis matrix W and the coefficient matrix H, as shown in Equation (2); that is, the column vectors of matrix B can be regarded as the sum of all column vectors in W multiplied by the corresponding column vectors in H.NMF is a non-negative matrix factorization proposed by Lee et al.  It decomW and coefficient matrix H. The key to NMF decomposition is the selection of an objective function and an iteration rule [T” represents the transpose.The essence of non-negative matrix decomposition is a process of constrained optimization solution , and theion rule . The objWhen the video is subjected to a malicious shearing attack, the damage to watermark information is irreversible; the dimension reduction effect achieved by NMF, and the feature of partial perception of the whole, can be applied to the watermark technology to improve its ability to resist shearing attack. Furthermore, its non-negative decomposition form and decomposition result has practical and explicable physical significance.NSCT is a multiscale and multi-decomposition geometric analysis algorithm proposed by da Cunha et al. . It is mThe multiscale characteristics of NSCT are realized by the NSP, and the direction decomposition is based on the NSDFB. The two sets of two-channel filter banks remove upsampling and subsampling from the decomposition process, and the direction sub-bands at all scales are the same size as the original image, and translation invariance is obtained. Applying the NSCT to the digital watermarking algorithm can improve the algorithm’s ability to resist translation and rotation on the one hand, and guarantee the embedding capacity of the watermark on the other hand .The video watermark embedding algorithm framework flowchart based on the pseudo 3D-DCT proposed in this paper is shown in Embedding the watermark on the luminance component Y not only has good robustness, but also has the smallest visual impact ; thus, tThe process of watermark embedding is as follows:(1)Extract the keyframe of the video and save the frame number as the key.(2)Transform the keyframe image into YCoCg color space, and group its Y components into a group every four frames.(3)Perform two-level NSCT on four Y-component graphs of the group, denoted as (4)In the pseudo 3D-DCT of (5)i, and the basis matrix NMF with (6)S is additive embedded into The encrypted watermark (7)Synthesize (8)Perform inverse pseudo 3D-DCT on the (9)(10)Place the keyframe back into the video according to the frame number to obtain the video sequence embedded with a watermark.The embedding strength of the watermark directly affects the performance of the watermarking algorithm. The robustness of the watermark algorithm will increase with increasing embedding strength, but its invisibility will decrease. The selection of embedding strength should balance the robustness with the invisibility of the watermark.We conducted multiple experiments on classic test videos , and determined the embedding strength of watermarks according to the experimental results. Experimental results show that when the PSNR value of the image containing the watermark is above 40, the invisibility of the watermark is better; that is, the embedded watermark has no obvious influence on the visual effect of the image. In the embedded-strength test experiment, when the value is above 55, the video picture quality will be significantly affected, which may be caused by uneven brightness and spots, etc., and the greater the embedded-strength is, the more obvious the spots will be. We further quantitatively evaluate the influence of embedding intensity on image quality. Video watermark extraction algorithm is the inverse process of watermark embedding, and its process is shown in (1)Find the video keyframe according to the frame number saved by the key.(2)i is decomposed into:According to the video watermark embedding algorithm, the NMF of the (3)Using the saved base matrix (4)Decrypt The experiments in this paper were carried out on the platform of Matlab 2017b, and the classic test videos  were used as the experimental videos. The video frame size of Foreman, Akiyo and Bus is 352 × 288, and the frame rate is 29 fps; the frame size of Claire is 176 × 144, and the frame rate is 29 fps. Except for the Bus video, which is 5 s, the other three videos are all 10 s. In order to unify the period, the size of the video frame was first redefined as 512 × 512 in the experiment, and the original size was restored after the watermark embedding was completed. The experiment used ‘Shandong University of Science and Technology’ as copyright protection to generate QR code watermark. The watermark size is 64 × 31, the parameters of logistic chaotic encryption in the experiment are Four classical test videos were embedded and extracted with watermarks. The number of keyframes extracted by the algorithm and CPU running time are shown in We used the video Akiyo as the test video, and carried out common attacks, such as Gaussian noise, salt and pepper noise, shearing, scaling, rotation, JPEG compression, Gaussian filtering, MPEG4 compression, H.264 compression, etc., and robustness tests under various combined attacks, the results of which are shown in In order to further investigate the performance of the algorithm under attack, this paper selected noise, rotation, shearing, filtering and combined attacks to conduct a large-scale experiment, the results of which are shown in (1)Noise attack. The added attack intensity is Gaussian and salt and pepper noise in the range of 0–0.1. The experimental results are shown in (2)Rotation attack. The added attack is a rotation of 15° in the range of 10–180°, and the result is shown in (3)Shearing attack. The added attack is to cut 1/16, 1/8 and 1/4 in the upper left and upper right corners, and 1/4 in the center. The experimental results are shown in (4)Filter attack. The added attack is Gaussian filtering with different window sizes and scales of Sigma = 1 and Sigma = 5. The experimental results are shown in (5)Combination attack. In this paper, three combined attacks of rotation plus salt and pepper noise, JPEG compression plus cropping, and Gaussian filtering and Gaussian noise under different windows were selected for experiments, and the results are shown in The algorithm in this paper is compared with two similar algorithms in the literature ,33. The In this paper, the same attack test was carried out on the literature-derived algorithms together with the proposed algorithm. The video watermarking algorithm presented in this paper combines the advantages of NSCT, pseudo 3D-DCT and NMF to achieve both invisibility and robustness, and can be used in video copyright protection. It can be seen from the experimental results that the algorithm in this research successfully achieves real-time performance and invisibility of video watermarking, and shows high robustness against various attacks, such as noise, shearing, filtering, JPEG compression, etc. Under all kinds of attacks in the experiment, the average NC values of the extracted watermark were above 0.90. Compared with the algorithm using 3D-DCT, the proposed algorithm has high real-time performance and strong anti-attack ability, especially in anti-rotation and anti-shearing attacks. Under rotation attacks in the range of 0–180°, the average NC values were about 0.98; under shearing attacks, the average NC values were above 0.9. In addition, the anti-attack effect under the other attacks also exhibited outstanding performance.The algorithm presented in this paper improves upon existing approaches in terms of robustness and comprehensive attack resistance. On the one hand, the algorithm presented in this paper will serve as a copyright authentication basis for multimedia that is vulnerable to most single or combined attacks, providing high robustness and comprehensive copyright protection for media publishers and organizations, as well as serving as a credential source for authentication agencies to certify high trustworthiness. The ideas and innovation of this algorithm, on the other hand, have implications for future research, and can be utilized as a useful research direction for high-performance copyright protection algorithms that can be further developed and optimized on this basis.It should be noted that, with the development of society, researchers will have higher requirements for the real-time performance, robustness, and invisibility of the algorithm. Consequently, in future applications, there is a need to further improve the real-time and robustness of the algorithm. An optional solution is to optimize the NMF and pseudo 3D-DCT algorithms. Beyond that, this algorithm is conditional for saving the secret key and the basis matrix so that the algorithm can be improved in the future, to realize the blinding or semi-blinding of the algorithm. Furthermore, the proposed algorithm is based on the original video in an uncompressed format, but in some application scenarios, the video needs to be compressed for storage and transmission. Therefore, the study of the video watermarking algorithm, combined with the encoding format, is a research direction that needs attention.