Commentary
In randomization we trust? There are overlooked problems in experimenting with people in behavioral intervention trials

https://doi.org/10.1016/j.jclinepi.2013.09.004Get rights and content
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Abstract

Objectives

Behavioral intervention trials may be susceptible to poorly understood forms of bias stemming from research participation. This article considers how assessment and other prerandomization research activities may introduce bias that is not fully prevented by randomization.

Study Design and Setting

This is a hypothesis-generating discussion article.

Results

An additivity assumption underlying conventional thinking in trial design and analysis is problematic in behavioral intervention trials. Postrandomization sources of bias are somewhat better known within the clinical epidemiological and trials literatures. Neglect of attention to possible research participation effects means that unintended participant behavior change stemming from artifacts of the research process has unknown potential to bias estimates of behavioral intervention effects.

Conclusion

Studies are needed to evaluate how research participation effects are introduced, and we make suggestions for how research in this area may be taken forward, including how these issues may be addressed in the design and conduct of trials. It is proposed that attention to possible research participation effects can improve the design of trials evaluating behavioral and other interventions and inform the interpretation of existing evidence.

Keywords

Behavior
Trials
Bias
Research participation
Intervention
Hawthorne effect

Cited by (0)

Funding: The work on this article was supported by a Wellcome Trust Research Career Development Fellowship in Basic Biomedical Science to the first author (WT086516MA). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.