Abstract
The aim of this study was to describe the clinical applicability of two different methods of aerobic fitness testing in patients with rheumatoid arthritis (RA). Five hundred and fifty-six patients with RA (median age 56 years, range 19–90, disease duration ≤6.5 years, 75% women) were included from 17 rheumatology units. Each patient was scheduled to perform a submaximal test of aerobic fitness, either on a bicycle or on a treadmill; the assignment to method was mainly determined by access to equipment at each participating unit. Eighty-eight patients (16%) were never tested, mainly because of use of beta-blockers or impairments, 45 patients (8%) terminated their tests prematurely and 423 patients (76%) completed their assigned test. Their estimated aerobic fitness was mainly classified as “low” (30%), “fair” (40%) or “average” (23%). The determinants of completing either of the tests were female gender (OR=2.06, 95% CI 1.22–3.47), age <65 years (OR=6.50, 95% CI 4.00–10.55) and no (OR=4.67, 95% CI 2.10–10.40) or mild disability (OR=6.24, 95% CI 2.43–16.06). It thus appears as if a majority of patients with RA are able to perform aerobic fitness testing despite the expected limitations related to impairments.