THE INFLUENCE OF ALLOCATION CONCEALMENT AND INTENTION TO TREAT ANALYSIS ON TREATMENT EFFECTS OF PHYSICAL THERAPY INTERVENTIONS IN LOW BACK PAIN RANDOMIZED CONTROLLED TRIALS: A META-EPIDEMIOLOGICAL STUDY

Abstract

The presence of methodological bias, such as inadequate allocation concealment and lack of intention to treat analysis may overestimate the treatment effects from randomized controlled trials. Meta-epidemiological studies have been performed in a large number of health-care fields. However, there are no studies investigating this issue in physical therapy interventions for low back pain. The aim of this study is to investigate the influence of allocation concealment and the use of intention to treat analysis on the treatment effects of physical therapy interventions in low back pain clinical trials. A search on PubMed, Embase, Cochrane Database of Systematic Reviews e PEDro databases will be performed. We will include a random sample of meta-analyses composed by randomized controlled trials that compared physical therapy interventions in patients with low back pain compared with placebo or no intervention, and have pain intensity or disability as the main outcome assessed. The evaluation of allocation concealment and the use of intention to treat analysis will be assessed following the Cochrane Handbook recommendations. Information about bibliographic data, study characteristics, participants' characteristics and study results will be extracted. A random effect model of meta-analyses will be used to pool the effect sizes. Finally, a meta-regression will be performed to assess the association between methodological features (allocation concealment and intention to treat analysis) and effect sizes. The dependent variable will be the effect size (the mean between-group differences) for the primary outcomes (pain or disability), while the independent variables will be the methodological features of interest (allocation concealment and intention-to-treat analysis). The results from this meta-epidemiological study are likely to bring new insights to the physical therapy scientific community by informing issues that need to be improved in randomized trials.