Association of patient copayment and medication adherence in systemic lupus erythematosus

Abstract

Objective To investigate the association of medication copayment and treatment adherence to hydroxychloroquine and immunosuppressants for SLE. Methods We conducted a retrospective analysis of health claims data using Optum's de-identified Clinformatics Data Mart Database. Individuals with SLE continuously enrolled for 180 days from 1 July 2010 to 31 December 2019 were included. Adherence was defined as the proportion of days covered ≥80%. Copayment for a 30-day supply of medication was dichotomised as high (≥$10) or low (