Complex interventions, such as exercise for LBP, often have many treatment targets. Matching a primary outcome to the target(s) of exercise interventions may provide greater standardized mean differences (SMDs) than using an unmatched primary outcome. We aimed to explore whether the conclusions of exercise trials for LBP might differ with i) improved matching of outcomes to treatment targets and ii) the use of composite outcome measures. We investigated i) matching in five trials (n=1033) that used an unmatched primary outcome but included some of their matched outcomes as secondary outcomes; ii) composite outcomes in four trials (n=864). The composite consisted of standardised averaged matched outcomes. All analyses replicated the primary outcome analysis, applied to the matched or composite outcome in each dataset. When not possible, SMDs were calculated for the primary and matched outcomes. i) Of five trials, three had greater SMDs and increased statistical significance with matched outcomes (pooled effect SMD 0.35 (95% CI 0.16, 0.54), p=0.0003) compared to an unmatched primary outcome (pooled effect SMD 0.13 (95% CI 0.04, 0.23) p=0.007). ii) Of four composite outcomes: two matched trials had greater SMDs and improved statistical precision in the primary outcome than the composite outcome; two unmatched trials had greater SMDs and improved statistical precision in the composite compared to the primary outcome.Background
Methods and Results
Advice and education are considered vital components of back pain care within national guidelines. However, a recent systematic review only found low grade evidence for a small average effect. They also reported wide heterogeneity in intervention design and delivery. This review aimed to understand why intervention design varied and what limited effectiveness by examining the underlying theoretical foundations of the studies from that review. Population, context, selection criteria, intervention(s), control, outcome measures, how the intervention was hypothesised to produce outcomes and author recommendations based on results of the study were extracted from text records. The extent to which the advice included matched a published international consensus statement on evidence-based advice for back pain was recorded. Whether interventions or settings were complex was determined using the Medical Research Council complex intervention development and evaluation guidance and the extent to which they met complexity reporting criteria was recorded.Background
Method
