THU0086 The Survival Impact of Statins in Rheumatoid Arthritis: A General Population-Based Cohort Study
Authors: S.R. Schoenfeld, L. Lu, S. Rai, Y. Zhang, H.K. Choi
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> Given their lipid-lowering and anti-inflammatory properties, statins may have dual cardioprotective [1] and anti-rheumatic benefits [2] in rheumatoid arthritis (RA). These effects are expected to confer survival benefits in RA patients, at least similar to those observed in the JUPITER trial [1] among otherwise healthy individuals with low LDL-cholesterol but with elevated hsCRP (i.e., a 20% reduction in overall mortality). However, no relevant data are available in the field. <h3>Objectives</h3> To address this knowledge gap, we evaluated the impact of statin initiation on the risk of mortality among RA patients in a general population context. <h3>Methods</h3> We conducted an incident user cohort study with time-stratified propensity score matching in a UK general population database. Our primary definition of RA required an RA diagnostic code with at least one use of a DMARD [3]. We compared statin initiators and non-initiators among patients with a new diagnosis of RA between January 2000 and December 2012. The outcome of interest was all-cause mortality. To closely account for confounding by indication and potential calendar-time effects, we employed propensity score-matched cohorts of statin initiators and non-initiators within 1-year cohort accrual blocks. Propensity scores (i.e., the predicted probability of statin initiation) were estimated using 50 variables, including RA duration, demographics, socio-economic status, body mass index, lifestyle factors, comorbidities, medication use, and healthcare utilization. We used Cox proportional hazard models to calculate hazard ratios for mortality. <h3>Results</h3> Of 2,943 statin initiators, 432 died during the follow up period (mean=4.51 years), whereas among 2,943 matched non-initiators, 513 died during the follow up period (mean = 4.29 years) (Table 1). This corresponds to incidence rates of 32.6/1000 person-years (PY) and 40.6/1000 PY in the statin initiator and comparator groups, respectively. The baseline characteristics were well-balanced in the two groups. Statin initiation was associated with a 21% reduction in all-cause mortality (HR 0.79, 95% CI 0.68-0.91) (Figure 1a). When we defined RA by its diagnosis code alone (not requiring DMARD use), the corresponding HR was 0.81 (95% CI 0.74-0.90). When we compared the unmatched cohorts to examine the effectiveness of our propensity score matching, the statin initiators (n=3,438) actually showed a 46% higher risk of mortality (HR 1.46, 95% CI 1.28-1.67) than non-initiators (n=3,438) due to confounding by indication (Figure 1b). <h3>Conclusions</h3> Findings from this general population study indicate that statin initiation is associated with a survival benefit among RA patients, and its magnitude is similar to that shown in the JUPITER trial among non-RA patients [1]. <h3>References</h3> The New England Journal of Medicine. 2008. 359(21):2195-2207. Lancet. 2004. 363(9426):2015-2021. Arthritis and Rheumatism. 2008. 59(9):1314-1321. <h3>Disclosure of Interest</h3> None declared