Higher self-reported disability (high Health Assessment Questionnaire [HAQ] score) has been associated with hospitalizations and mortality in established rheumatoid arthritis (RA), but associations in early RA are unknown.
Patients with early RA (symptom duration <1 year) enrolled in the Canadian Early Arthritis Cohort who initiated disease-modifying antirheumatic drugs and had completed HAQ data at baseline and 1 year were included in the study. Discrete-time proportional hazards models were used to estimate crude and multi-adjusted associations of baseline HAQ and HAQ at 1 year with all-cause mortality in each year of follow-up.
A total of 1,724 patients with early RA were included. The mean age was 55 years, and 72% were women. Over 10 years, 62 deaths (3.6%) were recorded. Deceased patients had higher HAQ scores at baseline (mean ± SD 1.2 ± 0.7) and at 1 year (0.9 ± 0.7) than living patients (1.0 ± 0.7 and 0.5 ± 0.6, respectively; P < 0.001). Disease Activity Score in 28 joints (DAS28) was higher in deceased versus living patients at baseline (mean ± SD 5.4 ± 1.3 versus 4.9 ± 1.4) and at 1 year (mean ± SD 3.6 ± 1.4 versus 2.8 ± 1.4) (P < 0.001). Older age, male sex, lower education level, smoking, more comorbidities, higher baseline DAS28, and glucocorticoid use were associated with mortality. Contrary to HAQ score at baseline, the association between all-cause mortality and HAQ score at 1 year remained significant even after adjustment for confounders. For baseline HAQ score, the unadjusted hazard ratio (HR) was 1.46 (95% confidence interval [95% CI] 1.02-2.09), and the adjusted HR was 1.25 (95% CI 0.81-1.94). For HAQ score at 1 year, the unadjusted HR was 2.58 (95% CI 1.78-3.72), and the adjusted HR was 1.75 (95% CI 1.10-2.77).
Our findings indicate that higher HAQ score and DAS28 at 1 year are significantly associated with all-cause mortality in a large early RA cohort.