Factors associated with permanent work disability in Mexican patients with rheumatoid arthritis. A case-control study

To assess factors associated with permanent work disability (PWD) in Mexican subjects with rheumatoid arthritis (RA).

From a database of 300 salaried workers with RA, we evaluated 35 cases that developed PWD. These cases were compared with 70 controls randomly selected from the same database who were active workers. The assessment included the following variables: sociodemographic, education, employment, and clinical characteristics of the disease. Logistic regression analysis was performed to adjust variables associated with PWD. Odds ratios and their 95% confidence intervals (95% CI) were computed.

Factors associated with PWD in the unadjusted analysis were: lower education level (OR 3.27, 95% CI 1.28-8.49, p = 0.006), >or= 2 year delay in prescription of a disease modifying antirheumatic drug (DMARD) (OR 4.29, 95% CI 1.49-12.73, p = 0.02), joint prosthesis (OR 8.93, 95% CI 2.02-45.04, p < 0.001), severe radiographic damage (OR 3.33, 95% CI 1.20-9.46, p = 0.01), comorbidity (OR 7.54, 95% CI 1.94-34.25, p < 0.001), and positive rheumatoid factor (RF) (OR 3.53, 95% CI 0.98-13.76, p = 0.03). In the multivariate model PWD was predicted by lower education (OR 3.3, 95% CI 1.1-9.7, p = 0.03), positive RF (OR 4.9, 95% CI 1.2-19.7, p = 0.03), and delay in the prescription of a DMARD (OR 3.3, 95% CI 1.1-10.1, p = 0.04).

A low education level, positive RF, and delay in the use of DMARD are risk factors for PWD. Strategies to decrease rates of PWD should include an earlier treatment with DMARD.