title: Correlates of the disability index of the health assessment questionnaire: a measure of functional impairment in systemic sclerosis.
abstract: OBJECTIVE
  To evaluate functional impairment in systemic sclerosis (SSc) patients with diffuse cutaneous scleroderma at the time of entry into a trial of a therapeutic intervention (D-penicillamine).
  
  
  METHODS
  The 20-item Disability Index of the Health Assessment Questionnaire (HAQ-DI) was administered to 134 patients as they entered a multicenter trial of high-dose versus low-dose D-penicillamine. All patients had diffuse SSc of < 18 months' duration. SSc patients who had severe organ system involvement and recent renal crisis and who were receiving prednisone > 10 mg/day were excluded from entry. Logistic regression modeling was used to examine the relationship of HAQ-DI scores to SSc skin and organ system involvement. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to estimate effects.
  
  
  RESULTS
  The mean (+/-SD) HAQ-DI score at entry was 1.04 +/- 0.67. Fifty-three percent of patients had HAQ-DI scores > or = 1.0 (signifying moderate-to-severe functional impairment). Multivariate logistic regression demonstrated that impaired fist closure > or = 23 mm (OR 4.24, 95% CI 1.68-10.70), reduced handspread < or = 175 mm (OR 4.5, 95% CI 1.80-11.24), joint tenderness count > or = 1.0 (OR 2.93, 95% CI 1.16-7.40), age > or = 43 years (OR 2.44, 95% CI 1.01-5.95), platelet count > or = 330,000/mm3 (OR 2.30, 95% CI 0.96-5.57), and female sex (OR 2.43, 95% CI 0.77-7.73) were the most important correlates of HAQ-DI scores > or = 1.0.
  
  
  CONCLUSIONS
  Increased HAQ-DI scores at baseline were correlated with reduced fist closure, reduced hand-spread, elevated platelet count, presence of tender joints, older age, and female sex. The most important contributor to functional impairment was hand dysfunction. Even within the first 18 months after SSc onset, moderate-severe functional impairment (HAQ-DI scores > or = 1.0) was frequent (53%) in this group of diffuse SSc patients. In early diffuse SSc, the self-administered HAQ-DI is therefore a valuable assessment of function that correlates with objective physical and laboratory measures of SSc disease involvement. Abnormal HAQ-DI scores may support patient claims of functional impairment, help to focus physician attention on implementing measures to reduce functional impairment, and be useful in reflecting the disease course over time.
authors.affiliation: University of California, Los Angeles, School of Medicine, 90095-1670, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Clements
authors.forename: W K
authors.initials: WK
authors.lastname: Wong
authors.forename: E L
authors.initials: EL
authors.lastname: Hurwitz
authors.forename: D E
authors.initials: DE
authors.lastname: Furst
authors.forename: M
authors.initials: M
authors.lastname: Mayes
authors.forename: B
authors.initials: B
authors.lastname: White
authors.forename: F
authors.initials: F
authors.lastname: Wigley
authors.forename: M
authors.initials: M
authors.lastname: Weisman
authors.forename: W
authors.initials: W
authors.lastname: Barr
authors.forename: L
authors.initials: L
authors.lastname: Moreland
authors.forename: T A
authors.initials: TA
authors.lastname: Medsger
authors.forename: V
authors.initials: V
authors.lastname: Steen
authors.forename: R
authors.initials: R
authors.lastname: Martin
authors.forename: D
authors.initials: D
authors.lastname: Collier
authors.forename: A
authors.initials: A
authors.lastname: Weinstein
authors.forename: E
authors.initials: E
authors.lastname: Lally
authors.forename: J
authors.initials: J
authors.lastname: Varga
authors.forename: S
authors.initials: S
authors.lastname: Weiner
authors.forename: B
authors.initials: B
authors.lastname: Andrews
authors.forename: M
authors.initials: M
authors.lastname: Abeles
authors.forename: J
authors.initials: J
authors.lastname: Seibold
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004185:Disability Evaluation; D005260:Female; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D016017:Odds Ratio; D010396:Penicillamine / Q000627:therapeutic use; D012595:Scleroderma, Systemic / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D011795:Surveys and Questionnaires
chemical_list: D010396:Penicillamine