Association Between Frailty Status and Readmissions in Hospitalized Patients With Systemic Lupus Erythematosus

Objective The objective of this study was to evaluate the association between frailty status and risk of readmissions, inpatient death, and cost of admission among patients with systemic lupus erythematosus (SLE). Methods We conducted a retrospective cohort study using the National Readmissions Database. Using International Statistical Classification of Diseases, Tenth Revision codes, we identified individuals >18 years of age who had a primary or secondary diagnosis of SLE and were hospitalized between January and June 2018. Using the validated claims‐based Hospital Frailty Risk Score, we categorized individuals as frail (score ≥ 5) or nonfrail (score < 5) at the time of index hospitalization. Our primary outcome was readmission rates post discharge from index hospitalization. Secondary outcomes were rates of inpatient mortality and the total cost of hospitalizations. Cox proportional hazard models were used to estimate the association between frailty and risk of readmissions, with adjustment for age, sex, insurance type, household income, and Elixhauser Comorbidity Index score. Results A total of 39,738 patients with SLE met eligibility criteria. Over a median follow‐up of eight months, frail patients with SLE (n = 18,385) had higher Elixhauser Comorbidity Index scores and longer length of stay compared to nonfrail patients with SLE (n = 21,353). Frail patients with SLE had higher readmission rates, a higher proportion of prolonged hospitalizations, and higher costs per hospitalization. Frailty was independently associated with a 10% higher risk of readmission after adjustment for covariates. Conclusion Among hospitalized adults with SLE, presence of frailty was associated with higher readmission and inpatient mortality rates. Our results highlight that frailty status can help risk stratify patients with SLE at increased risk for readmissions and other adverse health outcomes.