Although hydroxychloroquine/chloroquine (HCQ/CQ) form the cornerstone of systemic lupus erythematosus (SLE) treatment, not all patients receive this, which may contribute to disparities in outcomes. We investigated factors associated with first dispensing of HCQ/CQ.
Using Medicaid insurance claims from 2000-2010, we identified individuals age 18-65 years with incident SLE (≥3 SLE ICD-9 codes separated by ≥30 days without prior SLE codes or HCQ/CQ use for 24 months.) The primary outcome was first dispensing of HCQ/CQ within 24 months of the first SLE code. We used Cox proportional hazards regression models to examine the association between sociodemographic factors, comorbidities, health care utilization and medication use and HCQ/CQ dispensing within 24 months of diagnosis.
We identified 9560 Medicaid beneficiaries with incident SLE; 41% received HCQ (N=3949) or CQ (N=14) within 24 months of diagnosis. Younger patients were more likely to receive HCQ/CQ. Black, Asian, Hispanic and American Indian/Alaska Native individuals were more likely to receive HCQ/CQ than White individuals. Alcohol, opioid, and nicotine use, diabetes, and end-stage renal disease were associated with lower dispensing. Outpatient appointments and preventive care services were associated with higher rates; more hospitalizations with lower rates.
Only 41% of Medicaid beneficiaries with SLE received HCQ/CQ within 24 months of diagnosis. Greater outpatient and preventive care increased receipt. All non-White race/ethnicities had higher rates of first dispensing. Time to initial HCQ/CQ dispensing may not explain racial/ethnic disparities in adverse outcomes, highlighting the need to consider other care quality-related issues and medication adherence challenges.