Many PEDro users will be familiar with meta-analyses of randomised controlled trials. These involve the statistical combination of the results of trials that compare two interventions (one of these interventions could be a no treatment control or sham treatment). For example, Hannan et al (2018) identified all trials comparing high-intensity interval training to moderate intensity continuous training in the cardiac population, concluding that high-intensity training was superior to moderate-intensity training in improving cardiorespiratory fitness.
Over the past decade methods have been developed to examine the comparative effectiveness of many (or all) available interventions for a condition. Called network meta-analysis, these methods make both direct comparisons of interventions within randomised controlled trials and indirect comparisons across trials based on a common comparator. For example, Gao et al (2018) evaluated all minimally invasive interventions for obstructive sleep apnea. This network meta-analysis is summarised in the April 2018 PEDro newsletter.