Monitoring and assessing the safety of disease-modifying antirheumatic drugs: a West Midlands experience

Abstract

Background: Serious adverse events may occur from the use of disease modifying antirheumatic drugs (DMARDs) used to treat rheumatoid arthritis. We describe preliminary data from a regional surveillance scheme. Our aims were to identify a broad range of potential adverse events, to identify deficiencies in care and examine the management of common events in order to improve care.

Methods: Adverse events were sought by regular postcards to clinicians in the West Midlands region of the UK. Each reported case was carefully described and the opinions of at least three peer-reviewers were sought on cause-effect relationships, the potential for prevention and the appropriateness of management.

Results: Forty-four serious adverse events associated with DMARD use were reported between December 1999 and October 2001. Events included eight patients with malignancies, two with pancytopenia taking methotrexate, three with septic arthritis, and two with septicaemias. Fifteen cases have been peer-reviewed in detail, so far. At least two reviewers thought that eight events were related to DMARD use and that two were preventable. Agreement between pairs of reviewers was fair or moderate (weighted kappa 0.23-0.5).

Discussion: We have successfully implemented a regional system for identifying potential drug-related serious adverse events. A diverse range of potential drug-related events has been seen. Early analyses have highlighted the difficulties of determining cause-effect relationships between a drug and an event.