Dementia and Emergency Department Use in Older Adults With Systemic Lupus Erythematosus: An Administrative Claims Data Analysis of Medicare Beneficiaries.

Background/objective: Systemic lupus erythematosus (SLE) is associated with increased dementia risk. Whether this association is present among older adults with SLE is unclear. Further, whether individuals with concomitant SLE and dementia are at increased risk of emergency department (ED) use has not been explored. Using US Centers for Medicare & Medicaid Services (2006-2015) administrative claims data, we (1) quantified long-term all-cause dementia prevalence in adults with SLE ≥65 years of age and (2) determined whether dementia duration is associated with risk of ED visits in a cohort of older adults with SLE relative to comparators.

Methods: Medicare beneficiaries ≥65 years of age with SLE and age- and sex-matched comparators (1:4) with osteoarthritis were identified at baseline (2006). Dementia was considered a time-varying exposure, updated annually. Mixed-effect Poisson regression was used to estimate the effect of dementia duration on risk of multiple ED visits for the study period (January 2006 to September 2015), adjusting for relevant covariates.

Results: Baseline dementia prevalence was similar among beneficiaries with SLE (n = 1338 [4.6%]) and non-systemic rheumatic disease (non-SRD) comparators (n = 5352 [5.7%]). Stronger association between dementia duration and ED use was observed in older adults with SLE, including after adjustment for covariates (SLE: incidence rate ratio, 1.10; 95% confidence interval, 1.07-1.13; non-SRD: incidence rate ratio, 1.05; 95% confidence interval, 1.03-1.06).

Conclusions: Although dementia prevalence was similar between older adults with SLE and non-SRD comparators, dementia duration had a greater impact on ED use in aging adults with SLE versus non-SRD comparators. Geriatric assessment may be especially important in older adults with SLE.