Long-acting injectable versus daily oral antipsychotic treatment trials in schizophrenia: pragmatic versus explanatory study designs
Int Clin Psychopharmacol
Trial design characteristics related to the explanatory:pragmatic spectrum may contribute toward the inconsistent results reported in studies comparing long-acting injectable (LAI) versus daily oral antipsychotic (AP) treatments in schizophrenia. A novel approach examined the hypothesis that a more pragmatic design is important to show the advantages of LAI versus oral APs. A literature search identified comparative studies assessing the clinical efficacy/effectiveness of LAI versus oral APs in more than 100 schizophrenia patients, with 6-month or more duration/follow-up, and published between January 1993 and December 2013 (n=11). Each study's design was rated using the six-domain ASPECT-R (A Study Pragmatic:Explanatory Characterization Tool-Rating). Nonparametric Wilcoxon rank-sum tests compared ratings of studies supporting (n=7) and not supporting (n=4) a LAI advantage. ASPECT-R total and domain scores were significantly higher (more pragmatic) in studies finding a LAI versus oral AP treatment advantage than those that did not. The rank order of this significance among domains was as follows: participant compliance assessment' (P=0.005), medical practice setting/practitioner expertise' (P=0.006), intervention flexibility' (P=0.007), follow-up intensity/duration' (P=0.009), primary trial outcomes' (P=0.012), and participant eligibility' (P=0.015). Findings support that more pragmatic, less explanatory design features are important to show advantages for LAI treatment. Explanatory studies may introduce features that obscure advantages related to adherence.
School of Medicine