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. 2014 Mar;67(3):247-53.
doi: 10.1016/j.jclinepi.2013.09.004. Epub 2013 Dec 4.

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

Jim McCambridge  1 , Kypros Kypri  2 , Diana Elbourne  3
Affiliations

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

Jim McCambridge et al. J Clin Epidemiol. 2014 Mar.

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; Bias; Hawthorne effect; Intervention; Research participation; Trials.

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References

    1. Mokdad A.H., Marks J.S., Stroup D.F., Gerberding J.L. Actual causes of death in the United States, 2000. JAMA. 2004;291:1238–1245. PubMed PMID: 15010446. - PubMed
    1. Kinmonth A.L., Wareham N.J., Hardeman W., Sutton S., Prevost A.T., Fanshawe T. Efficacy of a theory-based behavioural intervention to increase physical activity in an at-risk group in primary care (ProActive UK): a randomised trial. Lancet. 2008;371:41–48. PubMed PMID: 18177774. Epub January 08, 2008. eng. - PubMed
    1. Solomon R.L. An extension of control group design. Psychol Bull. 1949;46(2):137–150. PubMed PMID: 18116724. Epub March 1, 1949. eng. - PubMed
    1. Godin G., Sheeran P., Conner M., Germain M. Asking questions changes behavior: mere measurement effects on frequency of blood donation. Health Psychol. 2008;27(2):179–184. PubMed PMID: 18377136. Epub April 2, 2008. eng. - PubMed
    1. Conner M., Godin G., Norman P., Sheeran P. Using the question-behavior effect to promote disease prevention behaviors: two randomized controlled trials. Health Psychol. 2011;30(3):300–309. PubMed PMID: 21553974. Epub May 11, 2011. eng. - PubMed

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