POS0694 REAL-WORLD ECONOMIC IMPLICATIONS OF ACHIEVING LOW DISEASE ACTIVITY IN LUPUS NEPHRITIS

Abstract

Background:Lupus nephritis (LN) is a common and severe manifestation of systemic lupus erythematosus (SLE) affecting 50% of SLE patients and leading to end-stage kidney disease (ESKD) in up to 30% of patients with LN.1 Previous studies have reported higher healthcare costs in patients with SLE that develop LN compared to patients without LN.2-5 These studies captured overall treatment costs associated with LN, regardless of disease activity or severity, and were conducted in small patient populations.Objectives:The aim of this study was to assess the real-world economic implications of achieving low disease activity compared to active disease or ESKD in a large LN population.Methods:This study was a retrospective observational analysis of patients with LN within Optum’s health plan identified with ICD9 or ICD10 codes to have LN between January 1, 2015, and December 31, 2019. Patients were ≥18 years of age and had ≥2 months of follow-up data available. Patients were followed until death, loss to follow-up, or December 31, 2019. Low disease activity was defined by evidence of glucocorticoid doses ≤5 mg/day, evidence of mycophenolate mofetil (MMF) doses ≤2 g/day, and no use of cyclophosphamide for ≥6 consecutive months. Follow-up time that could not be defined as low disease activity was defined as active disease periods, except for periods with evidence of ESKD. Healthcare payer costs for medical and pharmacy services were compared between periods of low disease activity, active disease, and ESKD. A univariate generalized estimating equation model accounting for interdependence was used to compare differences in costs between periods of active and low disease activity.Results:A total of 21,251 patients with LN met study criteria with a mean follow-up time of 31.0 months. The mean age was 60.3 years; 86.9% of patients were female and 35.2% of patients were non-White race. Low disease activity was evident in 51.3% of patients with a mean duration of 27.5 months. Mean monthly medical costs were $2,523 during periods of low disease activity and $4,777 during periods of active disease. After factoring in pharmacy costs, mean monthly total costs were $3,584 during periods of low activity and $6,612 during periods of active disease (P<0.001). The mean monthly costs of ESRD were $18,084 for medical and $3,760 for pharmacy.Conclusion:Achieving low disease activity in patients with LN is associated with reduced economic burden to healthcare payers, with monthly medical costs averaging $2,254 less and total monthly costs averaging $3,028 less than costs during periods of active disease.