Objective: To analyse and compare work disability attributed to rheumatoid arthritis in two cohorts of patients with early disease: one in the US and the other in Finland.
Patients and methods: Two cohorts of patients who were working and aged <65 years at the time of their first symptom of rheumatoid arthritis were studied: 269 patients in Nashville, TN, USA (median age 46 years, 72.5% females), and 364 patients from Jyväskylä, Finland, (median age 47.1 years, 70.9% females). The cohorts were analysed and compared for measures of clinical status and work disability status over a median (interquartile range) of 38.9 months in Nashville and 48.4 months in Jyväskylä.
Results: The probability of working at 36 months was 0.89 (0.84-0.92) for patients from Nashville and 0.84 (0.80-0.88) for patients from Jyväskylä (p = 0.02). These rates were lower than in earlier decades. Patients from Jyväskylä had significantly higher rates of work disability (p = 0.02) than those from Nashville, but better scores for self-report physical function (p<0.001), pain (p<0.001) and global status (p<0.001) at last observation. The likelihood of being disabled from work was 2.6-fold higher in Jyväskylä compared to Nashville (95% confidence interval 1.44 to 4.59, p = 0.001), after adjustment for demographic and disease-specific variables.
Conclusion: Rates of work disability in both early rheumatoid arthritis cohorts were improved from earlier decades, but differed significantly in two different social systems. Higher work disability rates with better clinical status was seen in the Finnish early rheumatoid arthritis cohort than in the US cohort.