Burden of lupus activity on health care resources utilization in Buenos Aires, Argentina.

Objective: The aim is to analyze health care resource utilization (HCRU) of patients with lupus (SLE) from a health management organization (HMO) in Buenos Aires, Argentina, compared with matched controls and comparing periods of flare, low disease activity, and remission.

Methods: This is a retrospective observational study including all SLE incident cases (ACR 1997/SLICC 2012 criteria) between 2000 and 2020 and 5 matched controls. Clinical data and HCRU (medical and nonmedical consultations, lab and imaging tests performed, emergency room visits, hospitalizations, and drugs prescribed) were obtained from administrative databases and electronic medical records. For each patient with SLE, an activity state was determined in every month of follow-up: flare (BILAG A or 2 BILAG B); low disease activity (LLDAS); remission (DORIS definition); or intermediate activity (not fulfilling any of previous). Incidence rates for each HCRU item and incidence rate ratios between SLE and control patients were and between remission and flare periods were calculated. Multivariate negative binomial logistic regression analyses were performed for identification of variables associated with major resource use.

Results: A total of 62 SLE and 310 control patients were included, 88.7% were women, the median age at diagnosis was 46 years, and were followed for more than 8 years. Patients with SLE contributed with 537.2 patient-years (CI 95% 461.1-613.3) and controls with 2761.9 patient-years (CI 95% 2600.9-2922.8). HCRU in patients with SLE was significantly higher than in controls in all items, even in remission periods. Patients with SLE remained 74.4% of the time in remission, 12.1% in LLDAS, 12.2% in intermediate activity, and 1.3% in flare (there were 64 flares in 36 patients). HCRU was significantly higher during flare periods compared with remission periods. Number of flares was independently associated with emergency department consultations, lab tests and X-ray performed, number of drugs prescribed, and hospitalizations.

Conclusion: Significantly more HCRU was observed in patients with SLE in flare compared to remission periods.