Effect of communicating genetic and phenotypic risk for type 2 diabetes in combination with lifestyle advice on objectively measured physical activity: protocol of a randomised controlled trial A randomized trial of the clinical utility of genetic testing for obesity: Design and implementation considerations Psychological impact of genetic testing for familial hypercholesterolemia within a previously aware population: A randomized controlled trial Changes in Physical Activity Following a Genetic-Based Internet-Delivered Personalized Intervention: Randomized Controlled Trial (Food4Me) Impact of a Randomized Controlled Educational Trial to Improve Physician Practice Behaviors Around Screening for Inherited Breast Cancer Improving diet, physical activity and other lifestyle behaviours using computer-tailored advice in general practice: a randomised controlled trial Genetic test feedback with weight control advice: study protocol for a randomized controlled trial Explaining the effects of an intervention designed to promote evidence-based diabetes care: a theory-based process evaluation of a pragmatic cluster randomised controlled trial Cluster randomised controlled trial of a peer-led lifestyle intervention program: study protocol for the Kerala diabetes prevention program Improving Diabetes care through Examining, Advising, and prescribing (IDEA): protocol for a theory-based cluster randomised controlled trial of a multiple behaviour change intervention aimed at primary healthcare professionals Genetic Susceptibility Testing and Readiness to Control Weight: Results from a Randomized Controlled Trial Personalized Genetic Risk Counseling to Motivate Diabetes Prevention Effects of a Web-Based Tailored Multiple-Lifestyle Intervention for Adults: A Two-Year Randomized Controlled Trial Comparing Sequential and Simultaneous Delivery Modes Looking inside the black box: a theory-based process evaluation alongside a randomised controlled trial of printed educational materials (the Ontario printed educational message, OPEM) to improve referral and prescribing practices in primary care in Ontario, Canada The clinical application of genetic testing in type 2 diabetes: a patient and physician survey Risky Business: Risk Perception and the Use of Medical Services among Customers of DTC Personal Genetic Testing Disclosure of Genetic Information and Change in Dietary Intake: A Randomized Controlled Trial
Type 2 diabetes ( T2D ) is associated with increased risk of morbidity and premature mortality . Among those at high risk , incidence can be halved through healthy changes in behaviour . Information about genetic and phenotypic risk of T2D is now widely available . Whether such information motivates behaviour change is unknown . We aim to assess the effects of communicating genetic and phenotypic risk of T2D on risk-reducing health behaviours , anxiety , and other cognitive and emotional theory-based antecedents of behaviour change . In a parallel group , open r and omised controlled trial , approximately 580 adults born between 1950 and 1975 will be recruited from the on-going population -based , observational Fenl and Study ( Cambridgeshire , UK ) . Eligible participants will have undergone clinical , anthropometric , and psychosocial measurements , been genotyped for 23 single-nucleotide polymorphisms associated with T2D , and worn a combined heart rate monitor and accelerometer ( Actiheart ® ) continuously for six days and nights to assess physical activity .  Participants are r and omised to receive either st and ard lifestyle advice alone ( control group ) , or in combination with a genetic or a phenotypic risk estimate for T2D ( intervention groups ) . The primary outcome is objective ly measured physical activity . Secondary outcomes include self-reported diet , self-reported weight , intention to be physically active and to engage in a healthy diet , anxiety , diabetes-related worry , self-rated health , and other cognitive and emotional outcomes . Follow-up occurs eight weeks post-intervention . Values at follow-up , adjusted for baseline , will be compared between r and omised groups . This study will provide much needed evidence on the effects of providing information about the genetic and phenotypic risk of T2D . Importantly , it will be among the first to examine the impact of genetic risk information using a r and omised controlled trial design , a population -based sample , and an objective ly measured behavioural outcome . Results of this trial , along with recent evidence syntheses of similar studies , should inform policy concerning the availability and use of genetic risk information . Current Controlled Trials IS RCT Background Obesity rates in the United States have escalated in recent decades and present a major challenge in public health prevention efforts . Currently , testing to identify genetic risk for obesity is readily available through several direct-to-consumer companies . Despite the availability of this type of testing , there is a paucity of evidence as to whether providing people with personal genetic information on obesity risk will facilitate or impede desired behavioral responses . Purpose We describe the key issues in the design and implementation of a r and omized controlled trial examining the clinical utility of providing genetic risk information for obesity . Methods Participants are being recruited from the Coriell Personalized Medicine Collaborative , an ongoing , longitudinal research cohort study design ed to determine the utility of personal genome information in health management and clinical decision making . The primary focus of the ancillary Obesity Risk Communication Study is to determine whether genetic risk information added value to traditional communication efforts for obesity , which are based on lifestyle risk factors . The trial employs a 2 × 2 factorial design in order to examine the effects of providing genetic risk information for obesity , alone or in combination with lifestyle risk information , on participants ’ psychological responses , behavioral intentions , health behaviors , and weight . Results The factorial design generated four experimental arms based on communication of estimated risk to participants : ( 1 ) no risk feedback ( control ) , ( 2 ) genetic risk only , ( 3 ) lifestyle risk only , and ( 4 ) both genetic and lifestyle risk ( combined ) . Key issues in study design pertained to the selection of algorithms to estimate lifestyle risk and determination of information to be provided to participants assigned to each experimental arm to achieve a balance between clinical st and ards and method ological rigor . Following the launch of the trial in September 2011 , implementation challenges pertaining to low enrollment and differential attrition became apparent and required immediate attention and modifications to the study protocol . Although monitoring of these efforts is ongoing , initial observations show a doubling of enrollment and reduced attrition . Limitations The trial is evaluating the short-term impact of providing obesity risk information as participants are followed for only 3 months . This study is built upon the structure of an existing personalized medicine study wherein participants have been provided with genetic information for other diseases . This nesting in a larger study may attenuate the effects of obesity risk information and has implication s for the generalizability of study findings . Conclusions This r and omized trial examines value of obesity genetic information , both when provided independently and when combined with lifestyle risk assessment , to motivate individuals to engage in healthy lifestyle behaviors . Study findings will guide future intervention efforts to effectively communicate genetic risk information This trial tests the hypothesis that confirming a clinical diagnosis of familial hypercholesterolemia ( FH ) by finding a genetic mutation reduces patients ' perceptions of control over the disease and adherence to risk‐reducing behaviors . Three hundred forty‐one families , comprising 341 hypercholesterolemia prob and s and 128 adult relatives , were r and omized to one of two groups : ( a ) routine clinical diagnosis ; ( b ) routine clinical diagnosis plus genetic testing ( mutation search ing in prob and s and direct gene testing in relatives ) . The main outcome measures were perceptions of control over hypercholesterolemia , adherence to cholesterol‐lowering medication , diet , physical activity , and smoking .  There was no support for the main hypothesis : finding a mutation had no impact on perceived control or adherence to risk‐reducing behavior ( all P‐values > 0.10 ) . While all groups believed that lowering cholesterol was an effective way of reducing the risk of a heart attack , participants in whom a mutation was found believed less strongly in the efficacy of diet in reducing their cholesterol level ( P = 0.02 at 6 months ) and showed a trend in believing more strongly in the efficacy of cholesterol‐lowering medication ( P = 0.06 at 6 months ) . In conclusion , finding a mutation to confirm a clinical diagnosis of FH in a previously aware population does not reduce perceptions of control or adherence to risk‐reducing behaviors . The pattern of findings leads to the new hypothesis that genetic testing does not affect the extent to which people feel they have control over a condition , but does affect their perceptions of how control is most effectively achieved . Further work is needed to determine whether similar results will be obtained in population s with little previous awareness of their risks . © 2004 Wiley‐Liss , Background There is evidence that  physical activity ( PA )  can attenuate the influence of the fat mass- and obesity-associated ( FTO ) genotype on the risk to develop obesity . However , whether providing personalized information on FTO genotype leads to changes in PA is unknown . Objective The purpose of this study was to determine if disclosing FTO risk had an impact on change in PA following a 6-month intervention . Methods The single nucleotide polymorphism ( SNP ) rs9939609 in the FTO gene was genotyped in 1279 participants of the Food4Me study , a four-arm , Web-based r and omized controlled trial ( RCT ) in 7 European countries on the effects of personalized advice on nutrition and PA . PA  was measured objective ly using a TracmorD accelerometer and was self-reported using the Baecke question naire at baseline and 6 months . Differences in baseline PA variables between risk ( AA and AT genotypes ) and nonrisk ( TT genotype ) carriers were tested using multiple linear regression . Impact of FTO risk disclosure on PA change at 6 months was assessed among participants with inadequate PA , by including an interaction term in the model : disclosure ( yes/no ) × FTO risk ( yes/no ) . Results At baseline , data on PA were available for 874 and 405 participants with the risk and nonrisk FTO genotypes , respectively . There were no significant differences in objective ly measured or self-reported baseline PA between risk and nonrisk carriers . A total of 807 ( 72.05 % ) of the participants out of 1120 in the personalized groups were encouraged to increase PA at baseline . Knowledge of FTO risk had no impact on PA in either risk or nonrisk carriers after the 6-month intervention . Attrition was higher in nonrisk participants for whom genotype was disclosed ( P=.01 ) compared with their at-risk counterparts . Conclusions No association between baseline PA and FTO risk genotype was observed . There was no added benefit of disclosing FTO risk on changes in PA in this personalized intervention . Further RCT studies are warranted to confirm whether disclosure of nonrisk genetic test results has adverse effects on engagement in behavior change . Trial Registration Clinical Trials.gov NCT01530139 ; http:// clinical trials.gov/show/NCT01530139 ( Archived by WebCite at : http://www.webcitation.org/6XII1QwHz ABSTRACT BACKGROUND Many primary care physicians ( PCPs ) are ill-equipped to provide screening and counseling for inherited breast cancer . OBJECTIVE To evaluate the outcomes of an interactive web-based genetics curriculum versus text curriculum for primary care physicians . DESIGN R and omized two-group design . PARTICIPANTS 121 California and Pennsylvania community physicians . INTERVENTIONWeb-based interactive genetics curriculum , evaluated against a control group of physicians who studied genetics review articles . After education , physicians interacted with an announced st and ardized patient ( SP ) at risk for inherited breast cancer . MAIN MEASURES Transcripts of visit discussion s were coded for presence or absence of 69 topics relevant to inherited breast cancer . KEY RESULTS Across all physicians , history-taking , discussion s of test result implication s , and exploration of ethical and legal issues were incomplete . Approximately half of physicians offered a genetic counseling referral ( 54.6 % ) , and fewer ( 43.8 % ) recommended testing . Intervention physicians were more likely than controls to explore genetic counseling benefits ( 78.3 % versus 60.7 % , P = 0.048 ) , encourage genetic counseling before testing ( 38.3 % versus 21.3 % , P = 0.048 ) , ask about a family history of prostate cancer ( 25.0 % versus 6.6 % , P = 0.006 ) , and report that a positive result indicated an increased risk of prostate cancer for male relatives ( 20.0 % versus 1.6 % , P = 0.001 ) . Intervention-group physicians were less likely than controls to ask about Ashkenazi heritage ( 13.3 % versus 34.4 % , P = 0.01 ) or to reply that they would get tested when asked , “ What would you do ? ” ( 33.3 % versus 54.1 % , P = 0.03 ) . CONCLUSIONS Physicians infrequently performed key counseling behaviors , and this was true regardless of whether they had completed the web-based interactive training or read clinical review Background The adoption and maintenance of healthy behaviours is essential in the primary prevention of chronic non-communicable diseases . This study evaluated the effectiveness of a minimal intervention on multiple  lifestyle factors such as  diet , physical activity , smoking and alcohol  , delivered through general practice , using computer-tailored feedback . Methods Adult patients visiting 21 general practitioners in Brisbane , Australia , were surveyed about ten health behaviours that are risk factors for chronic , non-communicable diseases . Those who completed the self-administered baseline question naire entered a r and omised controlled trial , with the intervention group receiving computer-tailored printed advice , targeting those health behaviours for which respondents were not meeting current recommendations . The primary outcome was change in summary lifestyle score ( Prudence Score ) and individual health behaviours at three months . A repeated measures analysis compared change in these outcomes in intervention and control groups after adjusting for age and education . Results 2306 patients were r and omised into the trial . 1711 ( 76 % ) returned the follow-up question naire at 3 months . The Prudence Score ( 10 items ) in the intervention group at baseline was 5.88 , improving to 6.25 at 3 months ( improvement = 0.37 ) , compared with 5.84 to 5.96 ( improvement = 0.12 ) in the control group ( F = 13.3 , p = 0.01 ) . The intervention group showed improvement in meeting recommendations for all individual health behaviours compared with the control group . However , these differences were significant only for fish intake ( OR 1.37 , 95 % CI 1.11 - 1.68 ) , salt intake ( OR 1.19 , 95 % CI 1.05 - 1.38 ) , and type of spread used ( OR 1.28 , 95 % CI 1.06 - 1.51 ) . Conclusion A minimal intervention using computer-tailored feedback to address multiple lifestyle behaviours can facilitate change and improve unhealthy behaviours . Although individual behaviour changes were modest , when implemented on a large scale through general practice , this intervention appears to be an effective and practical tool for population -wide primary prevention . Trial Registration The Australian New Zeal and Clinical Trials Registry : Background Genetic testing for risk of weight gain is already available over the internet despite uncertain benefits and concerns about adverse emotional or behavioral effects . Few studies have assessed the effect of adding genetic test feedback to weight control advice , even though one of the proposed applications of genetic testing is to stimulate preventive action . This study will investigate the motivational effect of adding genetic test feedback to simple weight control advice in a situation where weight gain is relatively common . Methods / design First-year university students ( n = 800 ) will be r and omized to receive either 1 ) their personal genetic test result for a gene ( FTO ) related to weight gain susceptibility in addition to a leaflet with simple weight control advice ( ‘ Feedback + Advice ’ group , FA ) , or 2 )  only the leaflet containing simple weight control advice ( ‘ Advice Only ’ group , AO).Motivation to avoid weight gain and active use of weight control strategies will be assessed one month after receipt of the leaflet with or without genetic test feedback .  Weight and body fat will be measured at baseline and eight months follow-up . We will also assess short-term psychological reactions to the genetic test result . In addition , we will explore interactions between feedback condition and gene test status . Discussion We hope to provide a first indication of the clinical utility of weight-related genetic test feedback in the prevention context .Trial registration Current controlled trials IS RCT Background The results of r and omised controlled trials can be usefully illuminated by studies of the processes by which they achieve their effects . The Theory of Planned Behaviour ( TPB ) offers a framework for conducting such studies . This study used TPB to explore the observed effects in a pragmatic cluster r and omised controlled trial of a structured recall and prompting intervention to increase evidence -based diabetes care that was conducted in three Primary Care Trusts in Engl and . Methods All general practitioners and nurses in practice s involved in the trial were sent a postal question naire at the end of the intervention period , based on the TPB ( predictor variables : attitude ; subjective norm ; perceived behavioural control , or PBC ) . It focussed on three clinical behaviours recommended in diabetes care : measuring blood pressure ; inspecting feet ; and prescribing statins . Multivariate analyses of variance and multiple regression analyses were used to explore changes in cognitions and thereby better underst and trial effects . Results Fifty-nine general medical practitioners and 53 practice nurses ( intervention : n = 55 , 41.98 % of trial participants ; control : n = 57 , 38.26 % of trial participants ) completed the question naire . There were no differences between groups in mean scores for attitudes , subjective norms , PBC or intentions . Control group clinicians had ' normatively-driven ' intentions ( i.e. , related to subjective norm scores ) , whereas intervention group clinicians had ' attitudinally-driven ' intentions ( i.e. , related to attitude scores ) for foot inspection and statin prescription . After controlling for effects of the three predictor variables , this group difference was significant for foot inspection behaviour ( trial group × attitude interaction , beta = 0.72 , p < 0.05 ; trial group × subjective norm interaction , beta = -0.65 , p < 0.05 ) . Conclusion Attitudinally-driven intentions are proposed to be more consistently translated into action than normatively-driven intentions . This proposition was supported by the findings , thus offering an interpretation of the trial effects . This analytic approach demonstrates the potential of the TPB to explain trial effects in terms of different relationships between variables rather than differences in mean scores . This study illustrates the use of theory-based process evaluation to uncover processes underlying change in implementation trials Background India currently has more than 60 million people with Type 2 Diabetes Mellitus ( T2DM ) and this is predicted to increase by nearly two-thirds by 2030 . While management of those with T2DM is important , preventing or delaying the onset of the disease , especially in those individuals at ‘ high risk ’ of developing T2DM , is urgently needed , particularly in re source -constrained setting s. This paper describes the protocol for a cluster r and omised controlled trial of a peer-led lifestyle intervention program to prevent diabetes in Kerala , India . Methods / design A total of 60 polling booths are r and omised to the intervention arm or control arm in rural Kerala , India . Data collection is conducted in two steps . Step 1 ( Home screening ) : Participants aged 30–60 years are administered a screening question naire . Those having no history of T2DM and other chronic illnesses with an Indian Diabetes Risk Score value of ≥60 are invited to attend a mobile clinic ( Step 2 ) . At the mobile clinic , participants complete question naires , undergo physical measurements , and provide blood sample s for biochemical analysis . Participants identified with T2DM at Step 2 are excluded from further study participation . Participants in the control arm are provided with a health education booklet containing information on symptoms , complications , and risk factors of T2DM with the recommended levels for primary prevention . Participants in the intervention arm receive : ( 1 ) eleven peer-led small group sessions to motivate , guide and support in planning , initiation and maintenance of lifestyle changes ; ( 2 ) two diabetes prevention education sessions led by experts to raise awareness on T2DM risk factors , prevention and management ; ( 3 ) a participant h and book containing information primarily on peer support and its role in assisting with lifestyle modification ; ( 4 ) a participant workbook to guide self-monitoring of lifestyle behaviours , goal setting and goal review ; ( 5 ) the health education booklet that is given to the control arm . Follow-up assessment s are conducted at 12 and 24 months . The primary outcome is incidence of T2DM . Secondary outcomes include behavioural , psychosocial , clinical , and biochemical measures . An economic evaluation is planned . Discussion Results from this trial will contribute to improved policy and practice regarding lifestyle intervention programs to prevent diabetes in India and other re source -constrained setting s . Trial registration Australia and New Zeal and Clinical Trials Registry : ACTRN12611000262909 Background New clinical research findings may require clinicians to change their behaviour to provide high- quality care to people with type 2 diabetes , likely requiring them to change multiple different clinical behaviours . The present study builds on findings from a UK-wide study of theory-based behavioural and organisational factors associated with prescribing , advising , and examining consistent with high- quality diabetes care . Aim To develop and evaluate the effectiveness and cost of an intervention to improve multiple behaviours in clinicians involved in delivering high- quality care for type 2 diabetes . Design / methods We will conduct a two-armed cluster r and omised controlled trial in 44 general practice s in the North East of Engl and to evaluate a theory-based behaviour change intervention . We will target improvement in six underperformed clinical behaviours highlighted in quality st and ards for type 2 diabetes : prescribing for hypertension ; prescribing for glycaemic control ; providing physical activity advice ; providing nutrition advice ; providing on-going education ; and ensuring that feet have been examined . The primary outcome will be the proportion of patients appropriately prescribed and examined ( using anonymised computer records ) , and advised ( using anonymous patient surveys ) at 12 months . We will use behaviour change techniques targeting motivational , volitional , and impulsive factors that we have previously demonstrated to be predictive of multiple health professional behaviours involved in high- quality type 2 diabetes care . We will also investigate whether the intervention was delivered as design ed ( fidelity ) by coding audiotaped workshops and interventionist delivery reports , and operated as hypothesised ( process evaluation ) by analysing responses to theory-based postal question naires . In addition , we will conduct post-trial qualitative interviews with practice teams to further inform the process evaluation , and a post-trial economic analysis to estimate the costs of the intervention and cost of service use . Discussion Consistent with UK Medical Research Council guidance and building on previous development research , this pragmatic cluster r and omised trial will evaluate the effectiveness of a theory-based complex intervention focusing on changing multiple clinical behaviours to improve quality of diabetes care . Trial registration IS RCT N66498413 Objective To test the hypothesis that adding obesity gene feedback ( FTO ) to simple weight control advice at a life stage with raised risk of weight gain ( university ) increases readiness to control weight . Methods Individually r and omized controlled trial comparing the effect of : ( i ) simple weight control advice plus FTO feedback ( FA ) and ( ii ) simple weight control advice only ( AO ) on readiness to engage with weight control . Differences in stage of change by genotype and differential weight control behaviors were secondary outcomes . Results Of 1,016 participants r and omized , only 279 completed follow-up , yielding 90 % power to detect a small effect for readiness to control weight . As predicted , FA participants were more likely to be in the contemplation stage than AO participants ( P = 0.023 ) . Participants receiving higher-risk genetic results were at a higher stage of change than controls ( P = 0.003 ) , with a trend toward a higher stage of change than those getting lower-risk results ( P = 0.051 ) . Lower-risk results did not decrease weight control intentions compared with controls ( P = 0.55 ) . There were no group differences in adherence to recommended weight control behaviors ( P = 0.87 ) . Conclusions Adding FTO feedback to weight control advice enhanced readiness to control weight , without evidence for genetic determinism , but had no more effect on behavior than weight control advice alone OBJECTIVE To examine whether diabetes genetic risk testing and counseling can improve diabetes prevention behaviors . RESEARCH DESIGN AND METHODS We conducted a r and omized trial of diabetes genetic risk counseling among overweight patients at increased phenotypic risk for type 2 diabetes . Participants were r and omly allocated to genetic testing versus no testing . Genetic risk was calculated by summing 36 single nucleotide polymorphisms associated with type 2 diabetes . Participants in the top and bottom score quartiles received individual genetic counseling before being enrolled with untested control participants in a 12-week , vali date d , diabetes prevention program . Middle-risk quartile participants were not studied further . We examined the effect of this genetic counseling intervention on patient self-reported attitudes , program attendance , and weight loss , separately comparing higher-risk and lower-risk result recipients with control participants . RESULTS The 108 participants enrolled in the diabetes prevention program included 42 participants at higher diabetes genetic risk , 32 at lower diabetes genetic risk , and 34 untested control subjects . Mean age was 57.9 ± 10.6 years , 61 % were men , and average BMI was 34.8 kg/m2 , with no differences among r and omization groups . Participants attended 6.8 ± 4.3 group sessions and lost 8.5 ± 10.1 pounds , with 33 of 108 ( 30.6 % ) losing ≥5 % body weight . There were few statistically significant differences in self-reported motivation , program attendance , or mean weight loss when higher-risk recipients and lower-risk recipients were compared with control subjects ( P > 0.05 for all but one comparison ) . CONCLUSIONS Diabetes genetic risk counseling with currently available variants does not significantly alter self-reported motivation or prevention program adherence for overweight individuals at risk for diabetes Background Web-based computer-tailored interventions for multiple health behaviors can have a significant public health impact . Yet , few r and omized controlled trials have tested this assumption . Objective The objective of this paper was to test the effects of a sequential and simultaneous Web-based tailored intervention on  multiple lifestyle behaviors . Methods A r and omized controlled trial was conducted with 3 tailoring conditions ( ie , sequential , simultaneous , and control conditions ) in the Netherl and s in 2009 - 2012 . Follow-up measurements took place after 12 and 24 months . The intervention content was based on the I-Change model . In a health risk appraisal , all respondents ( N=5055 )  received feedback on their lifestyle behaviors that indicated whether they complied with the Dutch guidelines for physical activity , vegetable consumption , fruit consumption , alcohol intake , and smoking .  Participants in the sequential ( n=1736 ) and simultaneous ( n=1638 ) conditions received tailored motivational feedback to change unhealthy behaviors one at a time ( sequential ) or all at the same time ( simultaneous ) . Mixed model analyses were performed as primary analyses ; regression analyses were done as sensitivity analyses . An overall risk score was used as outcome measure , then effects on the 5 individual lifestyle behaviors were assessed and a process evaluation was performed regarding exposure to and appreciation of the intervention . Results Both tailoring strategies were associated with small self-reported behavioral changes . The sequential condition had the most significant effects compared to the control condition after 12 months ( T1 , effect size=0.28 ) . After 24 months ( T2 ) , the simultaneous condition was most effective ( effect size=0.18 ) . All 5 individual lifestyle behaviors changed over time , but few effects differed significantly between the conditions . At both follow-ups , the sequential condition had significant changes in smoking abstinence compared to the simultaneous condition ( T1 effect size=0.31 ; T2 effect size=0.41 ) . The sequential condition was more effective in decreasing alcohol consumption than the control condition at 24 months ( effect size=0.27 ) . Change was predicted by the amount of exposure to the intervention ( total visiting time : beta=–.06 ; P=.01 ; total number of visits : beta=–.11 ; P<.001 ) . Both interventions were appreciated well by respondents without significant differences between conditions . Conclusions Although evidence was found for the effectiveness of both programs , no simple conclusive finding could be drawn about which intervention mode was more effective . The best kind of intervention may depend on the behavior that is targeted or on personal preferences and motivation . Further research is needed to identify moderators of intervention effectiveness . The results need to be interpreted in view of the high and selective dropout rates , multiple comparisons , and modest effect sizes . However , a large number of people were reached at low cost and behavioral change was achieved after 2 years . Trial Registration Nederl and s Trial Register : NTR 2168 ; http://www.trialregister.nl/trialreg/admin/ rct view.asp?TC=2168 ( Archived by WebCite at http://www.webcitation.org/6MbUqttYB ) Background R and omised controlled trials of implementation strategies tell us whether ( or not ) an intervention results in changes in professional behaviour but little about the causal mechanisms that produce any change . Theory-based process evaluations collect data on theoretical constructs alongside r and omised trials to explore possible causal mechanisms and effect modifiers . This is similar to measuring intermediate endpoints in clinical trials to further underst and the biological basis of any observed effects ( for example , measuring lipid profiles alongside trials of lipid lowering drugs where the primary endpoint could be reduction in vascular related deaths).This study protocol describes a theory-based process evaluation alongside the Ontario Printed Educational Message ( OPEM ) trial . We hypothesize that the OPEM interventions are most likely to operate through changes in physicians ' behavioural intentions due to improved attitudes or subjective norms with little or no change in perceived behavioural control . We will test this hypothesis using a well-vali date d social cognition model , the theory of planned behaviour ( TPB ) that incorporates these constructs . Methods / design We will develop theory-based surveys using st and ard methods based upon the TPB for the second and third replications , and survey a sub sample of Ontario family physicians from each arm of the trial two months before and six months after the dissemination of the index edition of informed , the evidence based newsletter used for the interventions . In the third replication , our study will converge with the " TRY-ME " protocol ( a second study conducted alongside the OPEM trial ) , in which the content of educational messages was constructed using both st and ard methods and methods informed by psychological theory . We will modify Dillman 's total design method to maximise response rates . Preliminary analyses will initially assess the internal reliability of the measures and use regression to explore the relationships between predictor and dependent variable ( intention to advise diabetic patients to have annual retinopathy screening and to prescribe thiazide diuretics for first line treatment of uncomplicated hypertension ) . We will then compare groups using methods appropriate for comparing independent sample s to determine whether there have been changes in the predicted constructs ( attitudes , subjective norms , or intentions ) across the study groups as hypothesised , and will assess the convergence between the process evaluation results and the main trial results .Trial registration numberCurrent controlled trial IS RCT Aims /hypothesisAdvances in type 2 diabetes genetics have raised hopes that genetic testing will improve disease prediction , prevention and treatment . Little is known about current physician and patient views regarding type 2 diabetes genetic testing . We hypothesised that physician and patient views would differ regarding the impact of genetic testing on motivation and adherence . Methods We surveyed a nationally representative sample of US primary care physicians and endocrinologists ( n = 304 ) , a r and om sample of non-diabetic primary care patients ( n = 152 ) and patients enrolled in a diabetes pharmacogenetics study ( n = 89 ) . Results Physicians and patients favoured genetic testing for diabetes risk prediction ( 79 % of physicians vs 80 % of non-diabetic patients would be somewhat/very likely to order/request testing , p = 0.7 ) . More patients than physicians ( 71 % vs 23 % , p < 0.01 ) indicated that a ‘ high risk ’ result would be very likely to improve motivation to adopt preventive lifestyle changes . Patients favoured  genetic testing to guide therapy ( 78 % of patients vs 48 % of physicians very likely to request/recommend testing , p < 0.01 ) and reported that genetic testing would make them ‘ much more motivated ’ to adhere to medications ( 72 % vs 18 % of physicians , p < 0.01 ) . Many physicians ( 39 % ) would be somewhat/very likely to order genetic testing before published evidence of clinical efficacy . Conclusions /interpretationDespite the paucity of current data , physicians and patients reported high expectations that genetic testing would improve patient motivation to adopt key behaviours for the prevention or control of type 2 diabetes . This suggests the testable hypothesis that ‘ genetic ’ risk information might have greater value to motivate behaviour change compared with st and ard risk information Direct-to-consumer  genetic testing has generated speculation about how customers will interpret results and how these interpretations will influence healthcare use and behavior ; however , few empirical data on these topics exist . We conducted an online survey of DTC customers of 23 and Me , deCODEme , and Navigenics to begin to address these questions . R and om sample s of U.S. DTC customers were invited to participate . Survey topics included demographics , perceptions of two sample DTC results , and health behaviors following DTC testing .  Of 3,167 DTC customers invited , 33 % ( n = 1,048 ) completed the survey . Forty-three percent of respondents had sought additional information about a health condition tested ; 28 % had discussed their results with a healthcare professional ; and 9 % had followed up with additional lab tests . Sixteen percent of respondents had changed a medication or supplement regimen , and one-third said they were being more careful about their diet . Many of these health-related behaviors were significantly associated with responses to a question that asked how participants would perceive their colon cancer risk ( as low , moderate , or high ) if they received a test result showing an 11 % lifetime risk , as compared to 5 % risk in the general population . Respondents who would consider themselves to be at high risk for colon cancer were significantly more likely to have sought information about a disease ( p = 0.03 ) , discussed results with a physician ( p = 0.05 ) , changed their diet ( p = 0.02 ) , and started exercising more ( p = 0.01 ) . Participants ’ personal health context s — including personal and family history of disease and quality of self-perceived health — were also associated with health-related behaviors after testing . Subjective interpretations of genetic risk data and personal context appear to be related to health behaviors among DTC customers . Sharing DTC test results with healthcare professionals may add perceived utility to the tests Background Proponents of consumer genetic tests cl aim that the information can positively impact health behaviors and aid in chronic disease prevention . However , the effects of disclosing genetic information on dietary intake behavior are not clear . Methods A double-blinded , parallel group , 2∶1 online r and omized controlled trial was conducted to determine the short- and long-term effects of disclosing nutrition-related genetic information for personalized nutrition on dietary intakes of caffeine , vitamin C , added sugars , and sodium . Participants were healthy men and women aged 20–35 years ( n = 138 ) . The intervention group ( n = 92 ) received personalized DNA-based dietary advice for 12-months and the control group ( n = 46 ) received general dietary recommendations with no genetic information for 12-months .  Food frequency question naires were collected at baseline and 3- and 12-months after the intervention to assess dietary intakes . General linear models were used to compare changes in intakes between those receiving general dietary advice and those receiving DNA-based dietary advice . Results Compared to the control group , no significant changes to dietary intakes of the nutrients were observed at 3-months . At 12-months , participants in the intervention group who possessed a risk version of the ACE gene , and were advised to limit their sodium intake , significantly reduced their sodium intake ( mg/day ) compared to the control group ( −287.3±114.1 vs. 129.8±118.2 , p = 0.008 ) . Those who had the non-risk version of ACE did not significantly change their sodium intake compared to the control group ( 12-months : −244.2±150.2 , p = 0.11 ) . Among those with the risk version of the ACE gene , the proportion who met the targeted recommendation of 1500 mg/day increased from 19 % at baseline to 34 % after 12 months ( p = 0.06 ) . Conclusions These findings demonstrate that disclosing genetic information for personalized nutrition results in greater changes in intake for some dietary components compared to general population -based dietary advice . Trial Registration Clinical Trials.gov
Several studies of good quality demonstrated changes in lifestyle habits arising from the provision of genetic interventions .
The most promising lifestyle changes were changes in nutrition .
Conclusions : It is possible to facilitate behaviour change using genetic testing as the catalyst .
Background : Study ing the impact of  genetic testing interventions on lifestyle behaviour change  has been a priority area of research in recent years .
Substantial heterogeneity exists in the results and conclusions of this literature , which has yet to be explained using vali date d behaviour change theory and an assessment of the quality of genetic interventions .
The theory of planned behaviour ( TPB ) helps to explain key contributors to behaviour change .
It has been hypothesized that personalization could be added to this theory to help predict changes in health behaviours .
Purpose : This systematic review provides a detailed , comprehensive identification , assessment , and summary of primary research articles pertaining to  lifestyle behaviour change  ( nutrition , physical activity , sleep , and smoking ) result ing from  genetic testing interventions .
The present review further aims to provide in-depth analyses of studies conducted to date within the context of the TPB and the quality of genetic interventions provided to participants while aim ing to determine whether or not genetic testing facilitates changes in lifestyle habits .
This review is timely in light of a recently published “ call-to-action ” paper , highlighting the need to incorporate the TPB into personalized healthcare behaviour change research .