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Meta-analysis suggest that the researcher allegiance effects substantial and robust in psychotherapy research.
Researcher allegiance in psychotherapy outcome research: An overview of reviews
Clinical Psychology Review
Volume 33, Issue 4, June 2013, Pages 501–511
Thomas Mundera, b, , ,
Oliver Brütscha,
Rainer Leonhartc,
Heike Gergera,
Jürgen Bartha
a Institute of Social and Preventive Medicine, University of Bern, Switzerland
b Institute of Psychology, University of Kassel, Germany
c Institute of Psychology, University of Freiburg, Germany
http://dx.doi.org/10.1016/j.cpr.2013.02.002,
Abstract*
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, I2 = 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.
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Highlights
► An overview of reviews on researcher allegiance and outcome was conducted.
► A substantial association of researcher allegiance and outcome was found.
► Moderator analyses supported the robustness of the allegiance-outcome association.
► Researcher allegiance can be considered a risk of bias in psychotherapy outcome research.
Keywords
Researcher allegiance;
Psychotherapy outcome research;
Overview of reviews
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