RESUMEN
INTRODUCTION: Media interventions can potentially play a major role in influencing health policies. This integrative systematic review aimed to assess the effects of planned media interventions-including social media-on the health policy-making process. METHODS: Eligible study designs included randomized and non-randomized designs, economic studies, process evaluation studies, stakeholder analyses, qualitative methods, and case studies. We electronically searched Medline, EMBASE, Communication and Mass Media Complete, Cochrane Central Register of Controlled Trials, and the WHO Global Health Library. We followed standard systematic review methodology for study selection, data abstraction, and risk of bias assessment. RESULTS: Twenty-one studies met our eligibility criteria: 10 evaluation studies using either quantitative (n = 7) or qualitative (n = 3) designs and 11 case studies. None of the evaluation studies were on social media. The findings of the evaluation studies suggest that media interventions may have a positive impact when used as accountability tools leading to prioritizing and initiating policy discussions, as tools to increase policymakers' awareness, as tools to influence policy formulation, as awareness tools leading to policy adoption, and as awareness tools to improve compliance with laws and regulations. In one study, media-generated attention had a negative effect on policy advocacy as it mobilized opponents who defeated the passage of the bills that the media intervention advocated for. We judged the confidence in the available evidence as limited due to the risk of bias in the included studies and the indirectness of the evidence. CONCLUSION: There is currently a lack of reliable evidence to guide decisions on the use of media interventions to influence health policy-making. Additional and better-designed, conducted, and reported primary research is needed to better understand the effects of media interventions, particularly social media, on health policy-making processes, and the circumstances under which media interventions are successful. TRIAL REGISTRATION: PROSPERO 2015: CRD42015020243.