Evaluation of adherence and persistence with oral versus long-acting injectable antipsychotics in patients with early psychosis

INTRODUCTION: Despite the theory that long-acting injectable (LAI) antipsychotics should be more likely to improve adherence, reduce gaps in therapy, and prevent relapse compared with oral antipsychotics, there is little published evidence on this issue, specifically in patients with early psychosis. METHODS: Patients with a new diagnosis for a psychotic disorder between July 1, 2013, and August 31, 2014, were retrospectively evaluated during a 12-month duration. The primary outcomes were adherence and persistence. Adherence was determined by proportion of days with medication, and persistence was defined as zero gaps in medication therapy. The secondary outcome was the number of times a psychiatric acute care service was used. Patients were divided into 3 groups based on their antipsychotic prescription history: oral only, LAI only, or both formulations at separate times throughout the study period. RESULTS: Forty-seven patients met inclusion criteria. The average proportions of days with medication were 32%, 76%, and 75% for the oral, LAI, and both formulations groups, respectively (P < .001). For medication persistence, there were 32 patients (91%), 3 patients (75%), and 5 patients (63%) with at least 1 gap in therapy for the oral, LAI, and both formulations groups, respectively (P = .098). For acute care services, there was a median number of zero acute care visits for each of the 3 groups (P = .179). A post hoc subgroup analysis found medication adherence to be statistically different between the oral and LAI groups. DISCUSSION: Long-acting injectable antipsychotics were associated with better adherence compared with oral antipsychotics in patients with early psychosis.