Objective: To investigate the course of disability related to the upper extremities (UEs) in early rheumatoid arthritis (RA), and to assess correlations between such disability and clinical variables, including grip force.
Methods: In an inception cohort of patients with early RA (diagnosed 1995-2005, N = 222, follow-up 10 yrs), disability of the UEs was assessed using a subscore of the Health Assessment Questionnaire-Disability Index (HAQ-DI-UE), and average grip force of the dominant hand was measured. Changes between consecutive follow-up visits in the HAQ-DI-UE subscore, and correlations at each visit with key clinical variables, were assessed. The relation between joint involvement and HAQ-DI-UE was examined using multivariate linear regression analysis.
Results: The HAQ-DI-UE decreased significantly from inclusion to the 6-month follow-up (mean change -0.26, 95% CI -0.18 to -0.34), and increased significantly after 2 years. There were fairly strong correlations for HAQ-DI-UE with grip force (r = -0.50 to -0.62), patient global assessment (r = 0.53 to 0.64), and patient-reported pain (r = 0.54 to 0.60) at all timepoints through 5 years, but only moderate to weak correlations with swollen joints, C-reactive protein, and erythrocyte sedimentation rate. At inclusion, wrist synovitis and tender proximal interphalangeal joints both had an independent effect on HAQ-DI-UE, whereas tenderness of the shoulder and the wrist had a greater importance at 6 months.
Conclusion: Disability related to the UEs decreased significantly during the first 6 months, and increased again after 2 years. The correlations with clinical variables underline the major effect of pain and impaired hand function in early RA.