Effectiveness of Paliperidone Palmitate on Treatment Adherence and Relapse in the Adult Schizophrenia Population: A One-Year Mirror-Image Study in a Colombian Mental Health Care Facility.

Abstract

Introduction: The benefits of long-acting injectable antipsychotics have been documented in several observational studies, but data remain scarce in Latin America. This study aimed at evaluating the effectiveness of paliperidone palmitate once monthly (PP1M) on treatment adherence and relapse in the schizophrenia population followed in a government-funded mental health care facility in Colombia.

Methods: A mirror-image study was conducted. Adult schizophrenia patients treated with oral antipsychotics who subsequently received ≥2 PP1M injections between Jan. 1^st, 2015 and Oct. 31^st, 2018 were included. The study consisted of two retrospective phases: 12 months before and after the first PP1M injection. Outcomes were treatment adherence (proportion of days covered ≥80%), hospitalized relapse, hospital length of stay, and non-hospitalised relapse. Effect of PP1M on outcomes was assessed through multivariable conditional Poisson regression.

Results: 123 patients were eligible (mean age, 30.3 years; 79.7% males). Adherence was 23.6% in the pre-phase and 89.4% in the post-phase (RR=3.77; 95%CI, 2.75-5.17). The proportion of patients with hospitalised relapse decreased from 46.3% to 35.0% (RR=0.76; 95%CI, 0.59-0.99). In the 75 (61.0%) patients who continued PP1M throughout post-phase, beneficial effect on hospitalised relapse was stronger (RR=0.64; 95%CI, 0.42-0.98). The proportion of patients with non-hospitalised relapse symptoms increased from 6.5% to 18.7% (RR=2.27; 95%CI, 1.11-4.64).

Conclusions: PP1M initiation led to a dramatic improvement in treatment adherence and a decrease in hospitalised relapse. Observed increase in non-hospitalised relapse may be explained by a decrease in severity. Limitations are absence of a parallel comparison group and a generalisability limited to the population treated at this facility. Study provides data for the Latin America region and strength is the assessment of non-hospitalised relapse symptoms.