The relationship between changes in self-reported disability (measured by the Health Assessment Questionnaire - HAQ) in scleroderma and improvement of disease status in clinical practice

Objectives. To determine if a low Health Assessment Questionnaire Disability Index (HAQ-DI) score predicts subsequent improvement over the next one to two years in clinical practice and if a low HAQ is predictive of improvement in early, late, diffuse and limited SSc subsets. Methods. HAQs collected at one site annually were used to determine serial relationships in low baseline HAQ and improvement in overall status over the following one to two years. Data were divided into early (53 years) and late, and then further into limited and diffuse SSc subgroups. We verified our results in the Canadian Scleroderma Research Group (CSRG) database. Results. 120 SSc patients had a baseline HAQ-DI of 0.97+/-0.07 (SEM). Low HAQs predicted improvement in overall HAQ at one and two years, but was not statistically significant in predicting physician improvement rating. However, improving HAQs were associated with improvement in physician assessment (better vs. same vs. worse) for overall SSc (p=0.005), early diffuse SSc (p=0.008), overall limited SSc (p=0.02) and late limited SSc (p=0.03) at I year (but not at 2 years). The relationship was similar for severity of disease where changes in damage were related to changes in HAQ only over the first year for all 4 subgroups. Conclusion. The HAQ is a useful 'marker' of change in status in clinical practice, where an improved HAQ is associated with improved physician global assessment. The relationship is only helpful for an interval of one year. Low HAQ did not predict subsequent improvement by physician rating in SSc patients.