(#30) Association of Antipsychotic Medication Nonadherence With All-Cause Mortality in Newly Treated Adults With Schizophrenia: A Retrospective Healthcare Claims Study

Abstract: Background: Clinical data support an association between antipsychotic nonadherence and adverse outcomes in schizophrenia; however, the influence of nonadherence on mortality remains unknown. Methods: The association between antipsychotic nonadherence and all-cause mortality was evaluated using longitudinal claims data (2011ñ2023). Eligible adults had ?2 outpatient claims on separate dates or ?1 inpatient claim with a schizophrenia diagnosis during the 12 months prior to or at index (ie, antipsychotic initiation date). Patient inclusion required ?12 months of continuous pre-index healthcare plan enrollment and no antipsychotic prescriptions or bipolar disorder diagnoses within 12 months pre-index. Adherence levels were defined by cumulative proportion of days covered (PDC): high adherence (?0.80), low/moderate adherence (?0.2 to 0.8), and nonadherence ( 0.2). Adherence and all-cause mortality were evaluated during follow-up. A marginal structural model adjusting for baseline and time-varying confounding factors was used to estimate hazard ratios (HRs) and 95% CIs for mortality at different adherence levels. Results: Of 6417 included adults (age=55.3±20.5 years; male=54.0%; White=51.0%), the majority (81.7%) were prescribed second-generation oral antipsychotics at index. Within 6 months of antipsychotic initiation, mean cumulative PDC was 0.59. Median duration of follow-up was 17 months. Patients with high adherence during follow-up were at significantly lower all-cause mortality hazard (HR, 0.56 [95% CI: 0.44ñ0.70]) than nonadherent patients. Five-year estimated survival rates were 80%, 71%, and 67% for high-adherent, low/moderate-adherent, and nonadherent patients, respectively. Conclusions: Antipsychotic nonadherence is associated with elevated mortality risk. Improved adherence may promote patient stability, and should be reinforced early in the course of disease.Short Description: In this longitudinal analysis of 6417 newly treated adults with schizophrenia, high adherence to antipsychotic medication (defined as a proportion of days covered [PDC] ?0.80) was associated with significantly lower mortality hazard (hazard ratio, 0.56 [95% CI: 0.44ñ0.70]) than nonadherence (PDC 0.2). Survival curves among adherence groups diverged rapidly and continued to separate over time, highlighting the need for interventions that support early and sustained antipsychotic adherence to reduce mortality risk.Name of Sponsoring Organization(s): Johnson & Johnson Innovative Medicine