Researcher allegiance in psychotherapy outcome research: an overview of reviews

Clin Psychol Rev. 2013 Jun;33(4):501-11. doi: 10.1016/j.cpr.2013.02.002. Epub 2013 Feb 21.


Researcher allegiance (RA) is widely discussed as a risk of bias in psychotherapy outcome research. The relevance attached to RA bias is related to meta-analyses demonstrating an association of RA with treatment effects. However, recent meta-analyses have yielded mixed results. To provide more clarity on the magnitude and robustness of the RA-outcome association this article reports on a meta-meta-analysis summarizing all available meta-analytic estimates of the RA-outcome association. Random-effects methods were used. Primary study overlap was controlled. Thirty meta-analyses were included. The mean RA-outcome association was r=.262 (p=.002, I(2)=28.98%), corresponding to a moderate effect size. The RA-outcome association was robust across several moderating variables including characteristics of treatment, population, and the type of RA assessment. Allegiance towards the RA bias hypothesis moderated the RA-outcome association. The findings of this meta-meta-analysis suggest that the RA-outcome association is substantial and robust. Implications for psychotherapy outcome research are discussed.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Meta-Analysis as Topic
  • Models, Statistical
  • Outcome Assessment, Health Care*
  • Psychotherapy*
  • Publication Bias*
  • Randomized Controlled Trials as Topic / ethics
  • Randomized Controlled Trials as Topic / statistics & numerical data*
  • Review Literature as Topic