The incidence of permanent work disability in patients with rheumatoid arthritis in Sweden 1990-2010: before and after introduction of biologic agents.

OBJECTIVE To explore the incidence of disability pension (DP) due to RA as an estimation of permanent work disability before and after introduction of biologic drugs. METHODS The annual incidence of DP was derived from the Swedish National Social Insurance Register and rates of DP due to RA were compared with the total amount of new DPs. RESULTS The incidence of DP due to RA has decreased over recent years, coinciding with earlier and more aggressive treatment with DMARDs and biologics. A similar declining incidence of DP was simultaneously seen in patients with all diagnoses in the general population. The decrease in DPs was, however, larger for RA and was evident even before introduction of biologics. In 1990, the proportion of DPs caused by RA was 1.9% out of total amount of DPs, decreasing to 1.5% in 2000 and to 1% in 2009. This may reflect effects of treatment, but may also be due to changing political policies as well as changes in age structure, increasing educational level and less physically demanding jobs. CONCLUSION The decrease in DPs due to RA coincides with new treatment strategies as well as with decreasing levels of DPs in patients with all diagnoses. Prevailing political and economic conditions have a large impact on permanent work disability and may affect patients with various diagnoses in different ways. To determine if the decline is a true effect of better treatment, there is a need for further investigations, taking possible confounding factors into account.