Background/Purpose: Patients with systemic lupus erythematosus (SLE) have an increased risk of osteoporosis, end-stage renal disease, cardiovascular disease, and other comorbidities. The presence of multiple chronic conditions (multimorbidity) is associated with disability and premature death. We aimed to compare the burden of multimorbidity in SLE patients with the general population.

Methods: An SLE cohort was assembled using OptumLabs Data warehouse (OLDW) from 1/2006-9/2015. SLE cases were identified using > 3 SLE ICD-9 codes separated > 30 days, the date of the third SLE code was considered the index date. SLE patients were matched to non-SLE comparators on age, sex, race, and enrollment date. Diagnosis codes from the period between enrollment and index date were used to determine the presence of comorbidities. Comorbidities were identified using the ICD-9 chronic condition indicator of the clinical classification software (healthcare cost and utilization project). SLE, cutaneous lupus, and rheumatoid arthritis ICD-9 codes were excluded from the analysis. Two or more ICD-9 codes at least 30 days apart were used to define a comorbidity. We defined multimorbidity as the presence of 2 or more comorbidities (excluding SLE) and substantial multimorbidity as the presence of 5 or more comorbidities. Conditional logistic regression models were performed.

Results: A total of 34,869 SLE patients were matched to 34,869 non-SLE comparators. The mean age was 48 (SD 14.2) years and 90.6% were female. 66.4% were White, 18.4% Black, 3.4% Asian and 18.4% Hispanic. The mean observation time from enrollment to index date was 2.3 (SD 2.4) years. Multimorbidity was present in 58.0% SLE vs. 26.3% non-SLE subjects (OR 5.0; 95%CI 4.8-5.2) and substantial multimorbidity was present in 21.2% SLE patients vs. 6.5% non-SLE subjects (OR 4.6; 95%CI 4.4-4.9). Of the 172 chronic conditions examined, 134 (78%) were more common in SLE than in non-SLE (Table).

Conclusion: In this nationwide commercial insurance database study, patients with SLE were five times as likely to suffer from multimorbidity and substantial multimorbidity compared to the general population. Most comorbidities were overrepresented in SLE patients. It is unclear if multimorbidity in SLE is driven by the disease activity, medication such as steroids, socioeconomic factors, or a combination of these.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/multimorbidity-burden-in-systemic-lupus-erythematosus-a-nationwide-study/