Abstract
To identify patterns of medication adherence during the pandemic and factors associated with these patterns among Medicaid-enrolled individuals with schizophrenia who had highly adherent medication use prior to the COVID-19 pandemic. We used Medicaid claims from Philadelphia to identify individuals with schizophrenia ≥ 18 years of age, their demographic characteristics, and health service use. We used group trajectory models to identify adherence trends, and ANOVA to examine associations between adherence groups and demographic characteristics and service use. The sample included 1,622 individuals. A 4-group trajectory model best fit our data. Seventy percent of individuals averaged about 92% adherence throughout the study period; 10% experienced a pronounced decline when the pandemic started (pandemic non-adherers); 11% experienced a sharp decline mid-pandemic (late non-adherers); and 9% experienced a sharp decline at the beginning of the pandemic and returned to higher adherence after a year (disrupted adherers). Adherers were least likely to be diagnosed with a substance use disorder, and had more telehealth visits, mental health outpatient visits, and fewer emergency department visits on average. Late non-adherers were more likely than adherers to have substance use disorders and physical health conditions. Pandemic non-adherers had more co-occurring psychiatric disorders than adherers and had the lowest use of case management. Three in ten previously adherent individuals with schizophrenia became less adherent to antipsychotic medications, either at the onset or later in the pandemic. Our findings point to telehealth and case management as critical strategies for treatment engagement, especially during public health crises, and well as the need to address co-occurring conditions.