Depression, medication adherence, and service utilization in systemic lupus erythematosus

Abstract

Objective: Forgetting to take medications is an important cause of nonadherence. This study evaluated factors associated with forgetting to take medications in a large cohort of persons with systemic lupus erythematosus (SLE) participating in the University of California, San Francisco Lupus Outcomes Study (LOS). Relationships among adherence problems and service utilization (outpatient visits, emergency department visits, and hospitalizations) were also evaluated.

Methods: The cohort consisted of 834 LOS participants who provided self-reported frequency of forgetting to take medications as directed. Predictors of adherence and service utilization patterns included self-reported sociodemographics, disease-related characteristics (e.g., disease activity, recent SLE flare), and mental health characteristics (Center for Epidemiologic Studies Depression Scale and cognitive function screen). Health care utilization patterns included the presence and quantity of visits to rheumatologists, primary care physicians, other care providers, emergency departments, and hospitalizations.

Results: Forty-six percent of the LOS cohort reported forgetting to take medications at least some of the time. Depressive symptom severity was a strong predictor of adherence difficulties (odds ratio [OR] 1.04, 95% confidence interval [95% CI] 1.02-1.05; P < 0.0001) after accounting for all other predictors. Persons reporting adherence difficulties had significantly greater numbers of outpatient rheumatology and primary care visits, and were more likely to visit the emergency department (OR 1.45, 95% CI 1.04-2.04; P = 0.03).

Conclusion: Depression may be an important cause of medication adherence problems, and difficulties with adherence are significantly associated with high-cost service utilization, specifically emergency department visits. In an era of rapidly evolving treatments for lupus, identifying patients at risk for adherence problems may decrease medical expenditures and improve patient outcomes in SLE.

Figure 1

Systemic Lupus Activity Questionnaire (SLAQ) disease activity scores among medication adherence groups.