INTRODUCTION / OBJECTIVES: While presence of concomitant SLE and frailty has been associated with greater emergency department (ED) use than SLE alone in young/mid-aged adults, whether frailty increases ED use in older adults with SLE remains unknown. In a nationally representative United States administrative claims dataset, we investigated the association of frailty duration with use of ED services in the SLE population compared with individuals without systemic rheumatic disease (SRD). METHOD: We identified Medicare beneficiaries ≥ 65 years with SLE and matched them (1:4) by age and gender with non-SRD comparators with osteoarthritis. Frailty was determined using a claims-based index and examined each study year (1/2006-9/2015). We used mixed-effect Poisson regression to ascertain the effect of frailty duration exposure on the risk of ED visits in those with SLE and in non-SRD participants, adjusting for covariates. RESULTS: At baseline (2006), frailty prevalence was similar in participants with SLE (N = 1338
43.7%) and no SRD (N = 5352
42.4%) (p = 0.37). Frailty prevalence significantly increased and diverged over time between participants with SLE versus no SRD (67.6% versus 63.7% in 2010 and 83.5% versus 78.1% in 2014) (p <
0.05). As frailty duration increased, risk of ED visits increased in both groups, including after covariate adjustment (SLE: incidence rate ratio [IRR] 1.10, 95% confidence interval [CI] 1.09-1.12
non-SRD: IRR 1.09, 95% CI 1.08-1.10). CONCLUSIONS: In this cohort of older adults, duration of frailty conferred similar increased risk of ED visits among those with and without SLE. This underscores the importance of measuring frailty in older populations with SLE. Key Points • Frailty prevalence was similar at baseline, and increased over time, in participants with SLE and those with no systemic rheumatic disease
however, frailty prevalence increased to a greater extent in those with SLE. • Frailty duration conferred similar increased risk of ED visits among older adults with and without SLE. • This underscores the importance of identifying, preventing, and/or reversing frailty in older populations with SLE and not assuming that SLE alone adequately explains health risks.