. (2014) 'Theory of planned behavior interventions for reducing heterosexual risk behaviors : a meta-analysis. ', Health psychology., 33 (12). pp. 1454-1467. Further information on publisher's website:http://dx.doi.org/10.1037/hea0000047Publisher's copyright statement:c 2014 APA, all rights reserved. This article may not exactly replicate the nal version published in the APA journal. It is not the copy of record.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Methods: Studies were eligible for inclusion if they were either randomized control trials or quasi-experimental studies which compared the TPB-based intervention against a control group. Search strategy consisted of papers identified in previous reviews, keyword search through search engines, examination of key journals, and contacting key experts.Results: Forty-seven intervention studies were included in the meta-analysis. Random effects models revealed that pooled effect sizes for TPB-based interventions had small but significant effects on behavior and other secondary outcomes (i.e., knowledge, attitudes, normative beliefs, perceived behavioral control, and intentions). Significant heterogeneity found between effect sizes was explored using meta-regression. Larger effects were found for interventions that provided opportunities for social comparison. Conclusions:The TPB provides a valuable framework for designing interventions to change heterosexual risk behaviors. However, effect sizes varied quite substantially between studies and further research is needed to explore the reasons why. They also linked their findings to specific components of the TPB. Interventions that included strategies addressing either attitudinal or behavioral skills arguments increased behavior change across many populations. Although the findings of this review do not provide direct evidence of the efficacy of using the TPB as a framework for intervention design, it has highlighted the benefits of targeting specific constructs.The systematic review and meta-analysis reported in this paper aims to build upon this work. It includes studies reporting evaluations of interventions that have been explicitly informed in their design by the TPB or its predecessor the TRA (both referred to hereafter as TPB-based interventions). Its focus is also somewhat broader than some of the existing reviews. It does not restrict itself to a particular population group or demographic and includes studies concerned with the prevention of all types of STDs contracted through heterosex...