Disability in systemic sclerosis -- a longitudinal observational study.

Area of Science:

• Rheumatology
• Clinical Epidemiology

Background:

• Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis, vascular abnormalities, and immune dysregulation.
• Longitudinal assessment of disability in SSc is crucial for understanding disease progression and patient outcomes.

Purpose of the Study:

• To longitudinally assess disability progression in patients with systemic sclerosis (SSc).
• To identify specific disease-related factors that predict disability in SSc.
• To account for informative patient dropout in the analysis of longitudinal disability data.

Main Methods:

• A multicenter, longitudinal study involving 745 patients with SSc from the Canadian Scleroderma Research Group registry.
• Disability was measured using the Health Assessment Questionnaire (HAQ).
• Statistical models were employed to analyze longitudinal changes in HAQ scores, specifically addressing various levels of informative patient dropout.

Main Results:

• Disability in SSc consistently worsened over time across all models.
• When informative patient dropout was considered, the annual increase in HAQ scores ranged from 0.039 to 0.071.
• Diffuse disease and respiratory complications were identified as the strongest correlates of increased disability.

Conclusions:

• Systemic sclerosis leads to a significant increase in disability over time.
• Breathing problems and the type of SSc (diffuse) are major predictors of disability.
• Longitudinal studies in SSc require statistical methods that account for informative patient dropout to accurately reflect disease outcomes.