OBJECTIVES : Patients with schizophrenia struggle with long-term adherence to antipsychotics (AP). This study evaluated incremental healthcare resource utilization (HRU) and costs among patients not adherent to APs with repeated schizophrenia relapses relative to controls without schizophrenia.

METHODS : Adults with ≥2 schizophrenia diagnoses and controls without schizophrenia were identified in Medicaid data (Q1/1998-Q1/2018) from six states. The index date was the last observed schizophrenia diagnosis (cohort with schizophrenia) or the last service claim (control cohort) with ≥12 months of continuous Medicaid enrollment before and after it. Cohorts were matched 1:1 using propensity scores. Analyses were then restricted to patients with schizophrenia not adherent to APs (proportion of days covered ≤80%) and with ≥2 schizophrenia-related hospitalizations (relapses) in the 12-month pre-index period and their matched controls. Per-patient-per-year HRU and costs ($2018 USD) in the 12-month post-index period were compared between matched pairs using regression models adjusted for unbalanced baseline characteristics. P-values were estimated using non-parametric bootstrap procedures.

RESULTS : Among all patients with schizophrenia, 13,779 (8.7%) were non-adherent with repeated relapses (mean age 47.1 years; 52.0% male). Non-adherent patients with relapses had 3.1 times more inpatient stays, 2.1 times more long-term care stays, 2.6 times more emergency room visits, and 1.5 times more outpatient visits relative to controls (all p<0.01); they incurred adjusted incremental healthcare costs of $21,688 versus controls (mean: $38,368 vs $15,271; p<0.01). Incremental costs were predominantly driven by inpatient ($8,417) and long-term care ($5,427) costs (all p<0.01). Incremental costs incurred by non-adherent patients with relapses were 54.0% higher than those of all patients with schizophrenia ($14,087).

CONCLUSIONS : Medicaid beneficiaries with schizophrenia not adherent to APs and with repeated relapses incurred substantial incremental HRU and costs relative to controls without schizophrenia. Incremental costs of non-adherent patients with schizophrenia and relapses appeared higher compared to those of all patients with schizophrenia.