Potential effects of a national consensus statement on optimal treatment of early rheumatoid arthritis in Ontario

The Ontario Biologics Research Initiative (OBRI) represents a collaboration of stakeholders (rheumatologists, patients, and researchers) aiming to improve rheumatoid arthritis (RA) management. Goals include the provision of real-world surveillance and evaluation, through administrative database linkages. Earlier population-based assessments have demonstrated that many Canadians are not provided optimal RA therapy (1, 2), especially older persons with RA (3). In 2004, the Canadian Rheumatology Association (CRA) convened an expert panel regarding optimal therapy in early RA. This led to the development and dissemination of a consensus statement; this reinforced the importance of early RA treatment, with methotrexate as the cornerstone. Our group recently examined Ontario provincial administrative data to determine whether appropriate drug therapy for older individuals with RA has improved since the CRA consensus statement was established. In light of the recent article by Carli et al (4), we thought it might be useful to report our findings, as they may shed additional light on the issues and questions at hand. We assembled an incident RA cohort aged ]65 years, using the administrative medical databases of the Ontario Health Insurance Plan (OHIP) for April 1998 to March 2007. In the province of Ontario, coverage for health services is universal. The OHIP physician billing database maintains information for physician services provided to all provincial beneficiaries, including physician diagnosis codes, provided as International Classification of Diseases (ICD) codes. Medication exposures were determined by the pharmacy claims database of the OHIP, which is limited to provincial residents aged 65 years or older. We relied on a standard algorithm (5) to identify RA patients within the OHIP billing data, based on at least two billing code diagnoses of RA (ICD code 714), ]60 days apart but within 5 years. We further required the subjects to have had at least one prescription for an oral glucocorticoid, diseasemodifying anti-rheumatic drug (DMARD), or biologic drug, in an effort to optimize our case definition specificity (6). The cohort was stratified into three subcohorts, according to calendar year of RA diagnosis: 1997 2000, 2001 2003, and 2004 2006. We followed subjects for 1 year, and assessed whether a subject had been exposed to methotrexate (defined as ]2 prescriptions). We then compared the percentage of early RA patients exposed to methotrexate over 2001 2003, vs. 2004 2006, calculating the difference, with 95% confidence intervals (CIs). However, to assess prescription trends that may have been unrelated to the consensus statement, we also looked for changes in 1997 2000 vs. 2001 2003. The results suggested a significant increase in methotrexate use over 2004 2006, vs. 2001 2003. The percentage of early RA patients exposed to methotrexate in 2001 2003 was 16.8% (95% CI 15.4 18.3) compared to 28.4% (26.5 30.3) in 2004 2006. This substantial increase was statistically significant (11.5%, 95% CI 9.2 13.9). However, when we looked at early periods, the percentage of early RA patients exposed to methotrexate in 1997 2000 was 9.9% (95% CI 9.1 10.9), indicating a very slight increase during 1997 2000 vs. 2001 2003 (6.8%, 95% CI 5.2% 8.5%), even before implementation of the CRA consensus statement. Carli et al (4) showed an upward trend in the prescription of DMARDs in Sweden since the implementation of national guidelines in 1998. Like them, we believe that a national guideline may lead to some improvements in RA care. However, we want to point out that, given the slight increase in use of methotrexate in our sample, which was evident even prior to the 2004 CRA guideline, other factors might explain some of our results. This possibility might be 390 Scand J Rheumatol 2009;38:390 401