Comparison and predictors of treatment adherence and remission among patients with schizophrenia treated with paliperidone palmitate or atypical oral antipsychotics in community behavioral health organizations

Abstract

Background: Nonadherence to antipsychotic treatment increases the likelihood of relapse and progressive symptomatology in patients with schizophrenia. Atypical long-acting injectables, including paliperidone palmitate (PP), may increase adherence and improve symptoms. This study compared and assessed predictors of treatment patterns and symptom remission among schizophrenia patients treated with PP versus atypical oral antipsychotic therapy (OAT) in community behavioral health organizations (CBHOs).

Methods: This retrospective cohort analysis evaluated 763 patients with schizophrenia and new (PP-N; N = 174) or continuing (PP-C; N = 308) users of PP, or new users of OAT (N = 281) at enrollment in the REACH-OUT study (2010-2013). Treatment outcomes assessed at 1 year were discontinuation, and adherence, measured by proportion of days covered (PDC) or medication possession ratio (MPR). Remission status was assessed using the Structured Clinical Interview for Symptoms of Remission (SCI-SR). A machine learning platform, Reverse Engineering and Forward Simulation (REFS™), was used to identify predictors of study outcomes. Multivariate Cox and generalized linear regressions estimated the adjusted hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals.

Results: Among PP-N users, 27% discontinued their initial treatment regimen versus 51% (p < 0.001) of OAT users. PP-N (vs OAT; HR = 0.49 [0.31-0.76]) users and males (HR = 0.65 [0.46-0.92]) had significantly lower rates of discontinuation. Relative to OAT, PP-N had a 36% [31%-42%] higher MPR and a 10-fold increased achievement of PDC ≥80% (OR = 10.46 [5.72-19.76]). PP users were significantly more likely to achieve remission in follow-up (PP-N vs OAT: OR = 2.65 [1.39-5.05]; PP-C vs OAT: OR = 1.83 [1.03-3.25]).

Conclusions: Relative to OAT, PP was associated with improved adherence, less frequent treatment discontinuation, and improved symptom remission in this CBHO study population.

Keywords: Adherence; Community behavioral health organization; Oral antipsychotics; Paliperidone palmitate; Remission; Schizophrenia.

Fig. 1

Selection of the study population. Abbreviations: LAI, long-acting injectable; OAT, oral antipsychotic therapy; PP, paliperidone palmitate; REACH-OUT, Research and Evaluation of Antipsychotic Treatment in Community Behavioral Health Organizations, Outcomes study. Notes: Reasons for REACH-OUT ineligibility (N = 99) included unknown or ineligible age (N = 34, 34%), most recent antipsychotic unknown or not study-eligible (N = 22, 22%), did not meet diagnostic criteria for schizophrenia or bipolar I disorder (N = 18, 18%), patient unwilling to complete scheduled study interviews (N = 17, 17%), patient participating in concurrent clinical study (N = 4, 4%), and patient did not consent (N = 4, 4%)

Fig. 2

Proportion of patients in remission by study visit and treatment status, REACH-OUT (2010–2013). Abbreviations: ENR, enrollment; OAT, oral antipsychotic therapy; PP-C, continuous user of paliperidone palmitate; PP-N, new user of paliperidone palmitate

Fig. 3

Predictors of disease remission,^a REACH-OUT (2010–2013). Abbreviations: DAI, Drug Attitude Inventory; PP-C, continuous user of paliperidone palmitate; PP-N, new user of paliperidone palmitate; REACH-OUT, Research and Evaluation of Antipsychotic Treatment in Community Behavioral Health Organizations, Outcomes study. ^aMultivariable logistic mixed effects regression model for disease remission (all SCI-SR domains mild or less), adjusted for all variables shown, plus proportion of days covered (by treatment, continuous), Personal and Social Performance scale score (≥70 vs <70), general life satisfaction (QOL domain, 4–7 [mixed/satisfied] vs 1–3 [dissatisfied]), and number of outpatient visits (continuous). Odds ratios and the 95% confidence intervals included