human
***task***
the task is to summarize an input biomedical literature in six sentences

***input***
the input is a biomedical literature

***output***
the output is the summary of an input biomedical literature in six sentences

***documentation***

***examples***

input: spondyloarthritis ( spa ) comprise a group of diseases that share certain common features such as spinal , sacroiliac and peripheral joint involvement , presence of enthesopathies , familial occurrence , and a frequent genetic association with the hla - b27 antigen . primary ankylosing spondylitis ( as ) , psoriatic arthritis ( psa ) , spa associated to inflammatory bowel disease ( spa ibd ) , and reactive arthritis are included in this group . furthermore , these diseases may present distinctive articular and extra - articular features . during the last years , some differences between male and female patients with as have been described . the early presentation in male as patients has been discussed , and the higher hla - b27 positivity in the male gender can be associated with this presentation . it has also been observed that female as patients present higher disease activity , higher fatigue scores , and more frequent peripheral involvement . on the contrary , the male gender is associated with more severe radiologic damage and a faster radiologic progression . moreover , women are more likely to present cervical spine involvement , whereas men tend to complain more frequently about lumbar pain . most studies that have assessed gender differences in patients with psa found similar findings to as . women report more frequent peripheral joint involvement and more functional disability , whereas the male gender is associated with axial involvement and more severe radiographic damage . it is important to consider that the clear definition of axial involvement in psa is still a matter of discussion . different proposals have been considered , such as unilateral / asymmetrical sacroiliitis , presence of syndesmophytes , and inflammatory back pain in association with limited movement of the spine . as there are few data regarding gender differences in patients with spa associated with psoriasis and ibd , the present study aims to describe and compare clinical manifestations , disease activity , functional capacity , axial mobility , and radiologic findings between men and women from a multicentric and multiethnic ibero - american cohort of patients with different spa . a total of 2044 consecutive spa patients fulfilling the european spondyloarthropathy study group ( essg ) classification criteria were included in an observational multicenter international cohort , the respondia registry ( registro iberoamericano de espondiloartritis ) , enrolled between june and december 2006 . data were collected by rheumatologists from different ibero - american countries , including argentina , brazil , costa rica , chile , ecuador , mexico , peru , uruguay , and portugal , who used a common protocol of investigation and later transmitted the data on - line to be stored on the database of the spanish spa registry ( regisponser ) , supported by the spanish society of rheumatology . a cross - sectional analysis was performed including only those patients that met modified new york criteria . patients identified as psoriatic spondylitis needed to further have skin disease and fulfill the chandran et al definition . patients with spa associated with ibd were included if they had crohn 's disease or ulcerative colitis plus axial involvement . socio - demographic data and information related to the disease , such as disease duration ( time since first symptom and inclusion in the study ) , diagnosis delay ( time since first symptom and diagnosis ) , presence of dactylitis , and enthesitis were recorded . disease activity was measured by bath ankylosing spondylitis disease activity index ( basdai ) , functional capacity by bath ankylosing spondylitis functional index ( basfi ) , quality of life assessment was carried out with the ankylosing spondylitis quality of life ( asqol ) questionnaire , and axial mobility was measured by the bath ankylosing spondylitis metrology index ( basmi ) . for enthesitis , the following anatomic regions were assessed : bilateral first and seventh costochondral joints , fifth lumbar spinous process , anterior superior iliac spines , iliac crests , posterior superior iliac spines , and achilles tendons . radiography studies of pelvis for sacroiliac joints ( ferguson view ) , lumbar , dorsal , and cervical spine were performed at entry , and the radiologic involvement was assessed according to the bath ankylosing spondylitis radiology index ( basri ) . special training and reliability exercise workshops for clinimetric , radiologic , and protocol procedures were performed by site investigators at a national or regional level , and were coordinated by the same experts ( ec - e and jv - m ) . radiography studies of sacroiliac joints were performed according to the routine techniques , but radiograph reading was not centralized . consensus about radiograph reading was reached during the training workshops , prior to the onset of the study . blood samples were obtained from all patients for determination of erythrocyte sedimentation rate ( esr ) by westergren 's method . finally , work disability was evaluated by direct questioning of the patients and was graded into 3 broad categories : absent , and if present as partial ( able to do at least 50 % of their work ) or total ( unable to do any work or permanent labor disability ) . patients gave written consent and the study was approved by the ethics board of the hospital ( named bioethics committee instituto de rehabilitacin psicofsica ) . categorical data were compared using the x or fisher 's exact test , and continuous variables by anova with levene variance homogeneity test and post - hoc analyses . multiple logistic regressions were performed using the gender as the dependent variable including those variables that had significance 0.01 . models with a classification capacity greater than 80 % were included . a value of p 0.05 was considered significant . categorical data were compared using the x or fisher 's exact test , and continuous variables by anova with levene variance homogeneity test and post - hoc analyses . multiple logistic regressions were performed using the gender as the dependent variable including those variables that had significance 0.01 . models with a classification capacity greater than 80 % were included . a value of p 0.05 was considered significant . from a total of 2044 patients included , 1264 met modified new york criteria ; 73 % were male ( mean age 42.9 years , sd = 15.8 ) , and 27 % female ( mean age 45.8 , sd = 12.6 ) ( table 1 ) . specifically , 1072 patients had primary as , 147 had psoriatic spondylitis , and 45 had ibd spondylitis . a significant male predominance was detected in as patients ( 76.2 % ) , whereas no difference was observed in psoriatic or ibd spondylitis ( fig .1 ) . clinical characteristics in the total spondyloarthritis population and according to specific diagnosis ( n = 1264 ) . ibd = inflammatory bowel disease , ns = non - significant . overall , male patients were significantly younger , had longer diagnostic delay , lower disease activity ( basdai ) , and better quality of life ( asqol ) , but worse spinal mobility ( basmi ) and higher radiologic score ( basri ) . presence of dactylitis and enthesitis , as well as swollen joint count , was significantly more frequent among women ( table 1 ) . esr was evaluated in 1081 patients and was significantly higher among women compared to men ( 28.98 mm / h vs 22.84 mm / h , p 0.001 ) , no additional associations were observed between esr and other disease parameters , including basdai and other patients reported outcomes . determination of c - reactive protein ( crp ) was not analyzed due to the small number of patients tested and different methods used for measurement . among primary as patients , besides the common characteristics shown by the whole male spa group , basri spine scores were also higher in men compared to women ( mean basri spine 7.3 vs 5.8 ; p = 0.001 ) . analyzing only psoriatic spondylitis , male gender presented less frequent peripheral involvement and worse spinal mobility ( basmi ) , as well as higher basri total and basri spine . patients with ibd spondylitis only differed regarding lateral flexion of the lumbar spine ( 49.910.5 in females vs 35.211.1 in males ; p = 0.01 ) . regarding treatment , patients with psoriatic spondylitis used disease - modifying antirheumatic drugs with more frequency ( mostly methotrexate and leflunomide ) , ibd patients used sulfasalazine , and patients with primary as used nonsteroidal anti - inflammatory drugs . given the fact that only 5.7 % of the total population was being treated with tumor necrosis factor inhibitors ( anti - tnf ) , no further analysis was considered to be made concerning this topic . regarding work disability in the total spa population , men presented higher permanent work disability ( 13.2 % vs 6.9 % ; p 0.05 ) . this difference persisted among as patients , but no difference was observed between psoriatic or ibd spondylitis ( fig . ibd = inflammatory bowel disease , ns = non - significant . spondyloarthritis comprise a group of chronic inflammatory diseases with axial and peripheral involvement which were originally considered as a group of diseases that primarily affected men . in 1949 , the male : female ratio was estimated to be 10:1 for as patients ; yet , recent data have established a new 23:1 ratio . according to recent publications and consistent with our findings , there are no differences in the prevalence of psoriatic or ibd spondylitis among men and women ; only a significant male predominance is detected in primary as , associated with more severe axial involvement and radiologic progression . in the present study , the male : female ratio was 3:1 for as , 1.3:1 for psoriatic spondylitis and 1:1 for ibd spondylitis . an interesting finding is that there are significant differences among the genders concerning clinical and radiologic presentation and disease indexes . men were significantly younger , presenting longer diagnostic delay and more severe radiologic damage ( measured by total basri ) . on the other hand , women referred higher involvement of peripheral joints , dactylitis and enthesitis , associated with higher disease activity ( basdai ) and worse quality of life ( asqol ) . similar data were observed in 1505 patients from the brazilian registry of spondyloarthritis ( rbe ) and 1514 patients from the spanish spa registry ( regisponser ) , as well as in a british study and in the french desir cohort , which included patients with axial spa of recent onset . the striking observation of a shorter diagnosis delay in females is in contrast to other publications and requires further investigation . first , family history of spa was not analyzed , having been shown that its presence is associated with lower delay , and second , in this cohort women presented worse disease activity ( basdai ) and quality of life ( asqol ) , which may have driven in a prompt medical consultation . it is worth to note that women reported significant higher indexes of disease activity ( basdai ) , disease functionality ( basfi ) , and quality of life ( asqol ) . a recent meta - analysis about different pain scores associated to the gender in inflammatory arthritis also found a significant higher peripheral involvement in women and axial involvement in men , recommending that future randomized trials and cohort studies recognize the need to evaluate for differential baseline pain levels and responses to treatment according to gender . in the present study , although women referred worse functional involvement and quality of life , male patients presented higher work disability , similar to what has been observed in the north - american psoas cohort . worth to note , although men showed higher permanent work disability in the overall population , they had a higher employment rate at study entry ( data not shown ) . it might be of interest to assess differences in employment rates in these countries according to the gender and if there is a larger interest in men to apply for work in comparison to women . similar to what has been observed in as , female patients with psoriatic spondylitis experienced better spinal mobility and lower radiologic damage . different risk factors have been associated with the development of axial involvement in patients with psoriasis , such as male sex , nail dystrophy , periostitis , radiologic joint involvement , and high esr and crp levels . therefore , it is possible that we had a selection bias in our population and that such bias could be due to the fact that we only used modified new york criteria in the absence of a unified consensus to define axial involvement in psoriatic patients . the new asas ( assessment of spondyloarthritis international society ) criteria were not available at the time that this study was carried out . regarding work disability , it has been proven in other studies that women with psoriatic arthritis experience higher work disability ; however , a small percentage of patients with axial involvement were included . in a recent study with patients with early psa , short diagnostic delay , preserved function , and male gender were the best predictors of good clinical outcome at 5 - year follow - up . a recent systematic review has shown that work disability is high in psa , but the small number of reports and the heterogeneity of the obtained data limit its interpretation . unfortunately , we did not analyze genetic associations among latin - american patients with spa , where native populations are quite heterogeneous in origin . although a small number of patients with ibd spondylitis were included , there were no significant gender differences among them , except for a lesser lateral flexion of the lumbar spine among men . one limitation of our study is that we employed self - administered questionnaires that limited a direct analysis of the impact of work disability and did not give further conclusion . moreover , as determination of hla - b27 was not mandatory for registration into the database and not all centers in latin america had easy access to hla testing , few patients had such test , precluding further analysis . a small number of patients with ibd spondylitis were recruited , probably due to the low prevalence of this disease with axial involvement . the cross section study design did not allow to further gather prospective data of this cohort , which could have resulted in valuable information regarding gender differences in spa along the time . hence , patients with non - radiograhic axial spa , where some gender differences in other studies were recently detected , were not included . it could be argued why basri scoring method was used instead of the modified stoke ankylosing spondylitis ( msass ) score . furthermore , at the moment of the study the msass scoring method had recently been developed and was not yet worldwide used to assess radiologic involvement . as this study was a cross sectional study , where no longitudinal data were going to be evaluated , the investigators considered that the basri method was a suitable tool . finally , it is important to note that the vast majority of this population was tnf naive , factor that could explain some differences with other recent cohorts that include only anti - tnf - treated patients . we conclude that spa may present different disease expressions according to gender in iberoamerican patients . further longitudinal studies are required to assess genetic background of gender differences in disease expression , especially in multiethnic cohorts like this .
output:

agent
abstractthe aim of the study was to compare clinical manifestations , disease activity , functional capacity , spinal mobility , and radiological findings between men and women from a multicenter , multiethnic ibero - american cohort of patients with spondyloarthritis ( spa ) . this observational cross - section study included 1264 consecutive spa patients who fulfilled the modified new york criteria for ankylosing spondylitis ( as ) . demographic , clinical , and radiologic data were evaluated . categorical data were compared by x2 or fisher 's exact tests and continuous variables by anova with post - hoc tests.primary as was diagnosed in 1072 patients , psoriatic spondylitis in 147 , and spondylitis associated to inflammatory bowel disease ( ibd ) in 45 patients . overall , male patients were significantly younger , had longer diagnostic delay , lower disease activity , worse spinal mobility , better quality of life , and more severe radiologic damage . dactylitis and enthesitis , as well as swollen joint count , were significantly more common among women . in primary as , there was a marked male predominance ( 76.2 % ) . among patients with psoriatic spondylitis , male predominance was lower ( 57.8 % ) , but was also associated with worse spinal mobility and more severe radiologic damage . in the total population , male patients with primary as referred higher permanent work disability ( 13.2 % vs 6.9 % ; p < 0.05 ) , although no difference was observed in psoriatic or ibd spondylitis according to the gender.among ibero - american spa patients , there are some differences in clinical and radiological manifestations , men showing more structural damage , whereas women more active disease . these data suggest that the phenotype of spa differs between genders . this can influence the subsequent diagnostic approach and therapeutic decisions .
***task***
the task is to summarize an input biomedical literature in six sentences

***input***
the input is a biomedical literature

***output***
the output is the summary of an input biomedical literature in six sentences

***documentation***

***examples***

input: spondyloarthritis ( spa ) comprise a group of diseases that share certain common features such as spinal , sacroiliac and peripheral joint involvement , presence of enthesopathies , familial occurrence , and a frequent genetic association with the hla - b27 antigen . primary ankylosing spondylitis ( as ) , psoriatic arthritis ( psa ) , spa associated to inflammatory bowel disease ( spa ibd ) , and reactive arthritis are included in this group . furthermore , these diseases may present distinctive articular and extra - articular features . during the last years , some differences between male and female patients with as have been described . the early presentation in male as patients has been discussed , and the higher hla - b27 positivity in the male gender can be associated with this presentation . it has also been observed that female as patients present higher disease activity , higher fatigue scores , and more frequent peripheral involvement . on the contrary , the male gender is associated with more severe radiologic damage and a faster radiologic progression . moreover , women are more likely to present cervical spine involvement , whereas men tend to complain more frequently about lumbar pain . most studies that have assessed gender differences in patients with psa found similar findings to as . women report more frequent peripheral joint involvement and more functional disability , whereas the male gender is associated with axial involvement and more severe radiographic damage . it is important to consider that the clear definition of axial involvement in psa is still a matter of discussion . different proposals have been considered , such as unilateral / asymmetrical sacroiliitis , presence of syndesmophytes , and inflammatory back pain in association with limited movement of the spine . as there are few data regarding gender differences in patients with spa associated with psoriasis and ibd , the present study aims to describe and compare clinical manifestations , disease activity , functional capacity , axial mobility , and radiologic findings between men and women from a multicentric and multiethnic ibero - american cohort of patients with different spa . a total of 2044 consecutive spa patients fulfilling the european spondyloarthropathy study group ( essg ) classification criteria were included in an observational multicenter international cohort , the respondia registry ( registro iberoamericano de espondiloartritis ) , enrolled between june and december 2006 . data were collected by rheumatologists from different ibero - american countries , including argentina , brazil , costa rica , chile , ecuador , mexico , peru , uruguay , and portugal , who used a common protocol of investigation and later transmitted the data on - line to be stored on the database of the spanish spa registry ( regisponser ) , supported by the spanish society of rheumatology . a cross - sectional analysis was performed including only those patients that met modified new york criteria . patients identified as psoriatic spondylitis needed to further have skin disease and fulfill the chandran et al definition . patients with spa associated with ibd were included if they had crohn 's disease or ulcerative colitis plus axial involvement . socio - demographic data and information related to the disease , such as disease duration ( time since first symptom and inclusion in the study ) , diagnosis delay ( time since first symptom and diagnosis ) , presence of dactylitis , and enthesitis were recorded . disease activity was measured by bath ankylosing spondylitis disease activity index ( basdai ) , functional capacity by bath ankylosing spondylitis functional index ( basfi ) , quality of life assessment was carried out with the ankylosing spondylitis quality of life ( asqol ) questionnaire , and axial mobility was measured by the bath ankylosing spondylitis metrology index ( basmi ) . for enthesitis , the following anatomic regions were assessed : bilateral first and seventh costochondral joints , fifth lumbar spinous process , anterior superior iliac spines , iliac crests , posterior superior iliac spines , and achilles tendons . radiography studies of pelvis for sacroiliac joints ( ferguson view ) , lumbar , dorsal , and cervical spine were performed at entry , and the radiologic involvement was assessed according to the bath ankylosing spondylitis radiology index ( basri ) . special training and reliability exercise workshops for clinimetric , radiologic , and protocol procedures were performed by site investigators at a national or regional level , and were coordinated by the same experts ( ec - e and jv - m ) . radiography studies of sacroiliac joints were performed according to the routine techniques , but radiograph reading was not centralized . consensus about radiograph reading was reached during the training workshops , prior to the onset of the study . blood samples were obtained from all patients for determination of erythrocyte sedimentation rate ( esr ) by westergren 's method . finally , work disability was evaluated by direct questioning of the patients and was graded into 3 broad categories : absent , and if present as partial ( able to do at least 50 % of their work ) or total ( unable to do any work or permanent labor disability ) . patients gave written consent and the study was approved by the ethics board of the hospital ( named bioethics committee instituto de rehabilitacin psicofsica ) . categorical data were compared using the x or fisher 's exact test , and continuous variables by anova with levene variance homogeneity test and post - hoc analyses . multiple logistic regressions were performed using the gender as the dependent variable including those variables that had significance 0.01 . models with a classification capacity greater than 80 % were included . a value of p 0.05 was considered significant . categorical data were compared using the x or fisher 's exact test , and continuous variables by anova with levene variance homogeneity test and post - hoc analyses . multiple logistic regressions were performed using the gender as the dependent variable including those variables that had significance 0.01 . models with a classification capacity greater than 80 % were included . a value of p 0.05 was considered significant . from a total of 2044 patients included , 1264 met modified new york criteria ; 73 % were male ( mean age 42.9 years , sd = 15.8 ) , and 27 % female ( mean age 45.8 , sd = 12.6 ) ( table 1 ) . specifically , 1072 patients had primary as , 147 had psoriatic spondylitis , and 45 had ibd spondylitis . a significant male predominance was detected in as patients ( 76.2 % ) , whereas no difference was observed in psoriatic or ibd spondylitis ( fig .1 ) . clinical characteristics in the total spondyloarthritis population and according to specific diagnosis ( n = 1264 ) . ibd = inflammatory bowel disease , ns = non - significant . overall , male patients were significantly younger , had longer diagnostic delay , lower disease activity ( basdai ) , and better quality of life ( asqol ) , but worse spinal mobility ( basmi ) and higher radiologic score ( basri ) . presence of dactylitis and enthesitis , as well as swollen joint count , was significantly more frequent among women ( table 1 ) . esr was evaluated in 1081 patients and was significantly higher among women compared to men ( 28.98 mm / h vs 22.84 mm / h , p 0.001 ) , no additional associations were observed between esr and other disease parameters , including basdai and other patients reported outcomes . determination of c - reactive protein ( crp ) was not analyzed due to the small number of patients tested and different methods used for measurement . among primary as patients , besides the common characteristics shown by the whole male spa group , basri spine scores were also higher in men compared to women ( mean basri spine 7.3 vs 5.8 ; p = 0.001 ) . analyzing only psoriatic spondylitis , male gender presented less frequent peripheral involvement and worse spinal mobility ( basmi ) , as well as higher basri total and basri spine . patients with ibd spondylitis only differed regarding lateral flexion of the lumbar spine ( 49.910.5 in females vs 35.211.1 in males ; p = 0.01 ) . regarding treatment , patients with psoriatic spondylitis used disease - modifying antirheumatic drugs with more frequency ( mostly methotrexate and leflunomide ) , ibd patients used sulfasalazine , and patients with primary as used nonsteroidal anti - inflammatory drugs . given the fact that only 5.7 % of the total population was being treated with tumor necrosis factor inhibitors ( anti - tnf ) , no further analysis was considered to be made concerning this topic . regarding work disability in the total spa population , men presented higher permanent work disability ( 13.2 % vs 6.9 % ; p 0.05 ) . this difference persisted among as patients , but no difference was observed between psoriatic or ibd spondylitis ( fig . ibd = inflammatory bowel disease , ns = non - significant . spondyloarthritis comprise a group of chronic inflammatory diseases with axial and peripheral involvement which were originally considered as a group of diseases that primarily affected men . in 1949 , the male : female ratio was estimated to be 10:1 for as patients ; yet , recent data have established a new 23:1 ratio . according to recent publications and consistent with our findings , there are no differences in the prevalence of psoriatic or ibd spondylitis among men and women ; only a significant male predominance is detected in primary as , associated with more severe axial involvement and radiologic progression . in the present study , the male : female ratio was 3:1 for as , 1.3:1 for psoriatic spondylitis and 1:1 for ibd spondylitis . an interesting finding is that there are significant differences among the genders concerning clinical and radiologic presentation and disease indexes . men were significantly younger , presenting longer diagnostic delay and more severe radiologic damage ( measured by total basri ) . on the other hand , women referred higher involvement of peripheral joints , dactylitis and enthesitis , associated with higher disease activity ( basdai ) and worse quality of life ( asqol ) . similar data were observed in 1505 patients from the brazilian registry of spondyloarthritis ( rbe ) and 1514 patients from the spanish spa registry ( regisponser ) , as well as in a british study and in the french desir cohort , which included patients with axial spa of recent onset . the striking observation of a shorter diagnosis delay in females is in contrast to other publications and requires further investigation . first , family history of spa was not analyzed , having been shown that its presence is associated with lower delay , and second , in this cohort women presented worse disease activity ( basdai ) and quality of life ( asqol ) , which may have driven in a prompt medical consultation . it is worth to note that women reported significant higher indexes of disease activity ( basdai ) , disease functionality ( basfi ) , and quality of life ( asqol ) . a recent meta - analysis about different pain scores associated to the gender in inflammatory arthritis also found a significant higher peripheral involvement in women and axial involvement in men , recommending that future randomized trials and cohort studies recognize the need to evaluate for differential baseline pain levels and responses to treatment according to gender . in the present study , although women referred worse functional involvement and quality of life , male patients presented higher work disability , similar to what has been observed in the north - american psoas cohort . worth to note , although men showed higher permanent work disability in the overall population , they had a higher employment rate at study entry ( data not shown ) . it might be of interest to assess differences in employment rates in these countries according to the gender and if there is a larger interest in men to apply for work in comparison to women . similar to what has been observed in as , female patients with psoriatic spondylitis experienced better spinal mobility and lower radiologic damage . different risk factors have been associated with the development of axial involvement in patients with psoriasis , such as male sex , nail dystrophy , periostitis , radiologic joint involvement , and high esr and crp levels . therefore , it is possible that we had a selection bias in our population and that such bias could be due to the fact that we only used modified new york criteria in the absence of a unified consensus to define axial involvement in psoriatic patients . the new asas ( assessment of spondyloarthritis international society ) criteria were not available at the time that this study was carried out . regarding work disability , it has been proven in other studies that women with psoriatic arthritis experience higher work disability ; however , a small percentage of patients with axial involvement were included . in a recent study with patients with early psa , short diagnostic delay , preserved function , and male gender were the best predictors of good clinical outcome at 5 - year follow - up . a recent systematic review has shown that work disability is high in psa , but the small number of reports and the heterogeneity of the obtained data limit its interpretation . unfortunately , we did not analyze genetic associations among latin - american patients with spa , where native populations are quite heterogeneous in origin . although a small number of patients with ibd spondylitis were included , there were no significant gender differences among them , except for a lesser lateral flexion of the lumbar spine among men . one limitation of our study is that we employed self - administered questionnaires that limited a direct analysis of the impact of work disability and did not give further conclusion . moreover , as determination of hla - b27 was not mandatory for registration into the database and not all centers in latin america had easy access to hla testing , few patients had such test , precluding further analysis . a small number of patients with ibd spondylitis were recruited , probably due to the low prevalence of this disease with axial involvement . the cross section study design did not allow to further gather prospective data of this cohort , which could have resulted in valuable information regarding gender differences in spa along the time . hence , patients with non - radiograhic axial spa , where some gender differences in other studies were recently detected , were not included . it could be argued why basri scoring method was used instead of the modified stoke ankylosing spondylitis ( msass ) score . furthermore , at the moment of the study the msass scoring method had recently been developed and was not yet worldwide used to assess radiologic involvement . as this study was a cross sectional study , where no longitudinal data were going to be evaluated , the investigators considered that the basri method was a suitable tool . finally , it is important to note that the vast majority of this population was tnf naive , factor that could explain some differences with other recent cohorts that include only anti - tnf - treated patients . we conclude that spa may present different disease expressions according to gender in iberoamerican patients . further longitudinal studies are required to assess genetic background of gender differences in disease expression , especially in multiethnic cohorts like this .
output:
