Changes in Physical Function using Three Methods of Scoring the Health Assessment Questionnaire in Established Active Rheumatoid Arthritis

Abstract

Background: We investigated sensitivity to change of three scoring methods of the Health Assessment Questionnaire (HAQ) in relation to change in disease activity in patients with active rheumatoid arthritis (RA). Patients and Methods: Adult RA-patients with complete data in the Measurement of Efficacy of Treatment in the Era of Outcome in Rheumatology database with respect to the 20 HAQ questions and disease activity score with 28-joint count using the erythrocyte sedimentation rate (DAS28-ESR) for 2 visits, at least 6–12 months apart, and high disease activity (DAS28-ESR >5.1) at visit 1. Changes in HAQ scored by the (1) conventional method (HAQ-8), (2) HAQ-Tomlin method (HAQ-T), and (3) HAQ-20-item method (HAQ-20) were analyzed in relation to the European League Against Rheumatism (EULAR) RA response criteria, dichotomized to good/moderate and no response. Results: In 421 patients, mean standard deviation (SD) DAS28-ESR declined significantly (6.1 [0.8]–4.8 [1.6], P < 0.0001), over a mean period (SD) of 8.7 (1.9) months. Median HAQ scores improved by all three scoring methods, HAQ-8 (1.6–1.4); HAQ-T (1.2–0.7); and HAQ-20 (1.2–0.9) with similar effect sizes of 0.97, 0.96, and 0.95, respectively. The proportion who achieved a HAQ minimally clinically important improvement (MCII) of ≥0.22 was significantly higher in 47% of patients with EULAR good/moderate score compared to the no response patients (64% vs. 11%, P < 0.0001). Good/moderate EULAR response, higher baseline DAS28, and higher baseline HAQ (7.11, 1.55, and 1.06, respectively) were independent predictors of achieving a HAQ-MCII. Conclusion: Three HAQ scoring methods performed similarly in sensitivity to change with no advantage of alternative scoring methods compared to the conventional HAQ-8 method. A good/moderate EULAR response, despite long disease duration, was associated with a significant likelihood of achieving a HAQ-MCII.