Underreporting of the Active Content of Behavioural Interventions: A Systematic Review and Meta-Analysis of Randomized Trials of Smoking Cessation Interventions
Research article
Abstract
Introduction
Despite its importance, underreporting of the active content of experimental and comparator interventions in the published literature has not been previously examined for behavioural trials.
Method
The study assessed completeness and variability in reporting in 142 randomised controlled trials (RCTs) of behavioural interventions for smoking cessation published between 1/1996-11/2015. Two coders reliably identified the potential active components of experimental and comparator interventions (activities targeting behaviours key to smoking cessation and qualifying as behaviour change techniques, BCTs) in published, and in unpublished materials obtained from study authors directly.
Results
Unpublished materials were obtained for 129/204 (63%) experimental and 93/142 (65%) comparator groups. For those, only 35% (1200/3403) of experimental and 26% (491/1891) of comparator BCTs could be identified in published materials. Reporting quality (#published BCTs/#total BCTs) varied considerably between trials and between groups within trials. Experimental (vs. comparator) interventions were better reported (B(SE) = 0.34 (0.11), p < .001). Unpublished materials were more often obtained for recent studies (B(SE) = 0.093 (0.03), p = .003) published in behavioural (vs. medical) journals (B(SE) = 1.03 (0.41), p = .012).
Conclusion
This high variability in underreporting of active content compromises reader’s ability to interpret the effects of individual trials, compare and explain intervention effects in evidence syntheses, and estimate the additional benefit of an experimental intervention in other settings.
