title: Gender and ethnicity differences in patients with diffuse systemic sclerosis--analysis from three large randomized clinical trials.
abstract: OBJECTIVE
  Although the incidence of dcSSc is higher in African-American and Hispanic populations compared with European Caucasian patients, it is not clear whether there are differences in subsequent disease course. Also, the potential impact of gender on the disease course of dcSSc is not well defined. Our objective was to assess the course of modified Rodnan skin score (MRSS), HAQ-disability index (HAQ-DI) and forced vital capacity per cent (FVC%) predicted between men vs women and three ethnic groups with dcSSc participating in three randomized clinical trials (RCTs).
  
  
  METHODS
  Data from RCTs (n = 495) were pooled and analysed. Baseline characteristics were compared in men vs women and among ethnic groups. A linear mixed effects model was used to assess the predictors of MRSS, HAQ-DI and FVC%. The primary independent variables were time-in-study and its interaction with gender and ethnicity. The models were adjusted for other covariates that were significant at baseline between gender and ethnicity analyses.
  
  
  RESULTS
  Men had lower HAQI-DI scores compared with women (P < 0.05). Among the three ethnic groups, Caucasians were older, African-Americans had lower FVC% predicted and Hispanics had greater tender joint counts (P < 0.05). The course of MRSS, HAQ-DI and FVC% predicted during the study period was not significantly different between gender and three ethnicities. Time-in-study was an independent predictor of improvement in MRSS and HAQ-DI.
  
  
  CONCLUSIONS
  Our analysis explores the influence of gender and ethnicity on disease course in RCTs. These findings are relevant to issues of future trial design.
authors.affiliation: Department of Medicine, David Geffen School of Medicine, Los Angeles, CA 90095, USA.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Nashid
authors.forename: Puja P
authors.initials: PP
authors.lastname: Khanna
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Furst
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Clements
authors.forename: Paul
authors.initials: P
authors.lastname: Maranian
authors.forename: James
authors.initials: J
authors.lastname: Seibold
authors.forename: Arnold E
authors.initials: AE
authors.lastname: Postlethwaite
authors.forename: James S
authors.initials: JS
authors.lastname: Louie
authors.forename: Maureen D
authors.initials: MD
authors.lastname: Mayes
authors.forename: Harsh
authors.initials: H
authors.lastname: Agrawal
authors.forename: Dinesh
authors.initials: D
authors.lastname: Khanna
mesh_terms: D000328:Adult; D001741:Black or African American / Q000208:ethnology; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006630:Hispanic or Latino / Q000208:ethnology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D045743:Scleroderma, Diffuse / Q000208:ethnology* / Q000473:pathology; D012720:Severity of Illness Index; D012737:Sex Factors; D013223:Statistics as Topic; D044465:White People / Q000208:ethnology