Late-onset rheumatoid arthritis: is pitting oedema of the hands at onset a good prognostic indicator?

This prospective study compares the clinical and radiological outcome of patients with late-onset (age 65 yr and over) rheumatoid arthritis (RA) presenting with and without pitting oedema of the hands (POH). Twenty-two patients with POH (Group 1) were compared with 81 (Group 2) without POH (median age of onset of RA-Group 1: 74.3; Group 2: 73.1; female to male. ratio-Group 1: 1.2:1; Group 2: 2.5:1). The median time between the onset of arthritis and baseline assessment was 3 months. Minimum follow-up was 1 yr (median 2.4). Outcome was defined by (1) the development of erosions of the hands, wrists or feet and (2) the number of patients in remission (clinically inactive disease on two clinic visits 3 months apart with no intervening history of inflammatory joint disease). IgM rheumatoid factor (IgM RF) was less frequent in patients with POH (Group 1:8.2%; Group 2: 43.2%, P < or = 0.05). Logistic regression analysis showed that POH at onset was independent of IgM RF in determining outcome. Patients with POH were less likely to develop erosions [odds ratio (OR) = 0.16, 95% confidence interval (CI) 0.03, 0.89]. Although initial cross-tabulation suggested an increased frequency of remission in Group 1 (Group 1: 90.9%; Group 2: 55.5%, P = 0.02), POH was not found to be a significant predictor using the logistic regression model (OR = 7.42, 95% CI 0.84, 65.7). Patients with IgM RF were more likely to develop erosions (OR = 5.1, 95% CI 1.46, 17.67) and less likely to go into remission (OR = 0.19, 95% CI 0.06, 0.68).