Introduction: Besides supply reduction, preventive interventions to reduce harm from gambling include interventions for the reduction of demand and to limit negative consequences. Several interventions are available for gamblers, e.g. limit-setting. Reviews have been published examining the evidence for specific measures as well as evaluating the effect of different measures at an overall level. Only a few of these have used a systematic approach for their literature review. The aim of this systematic review and meta-analysis is twofold. First, to assess the certainty of evidence of different preventive measures in the field of educational programs and consumer protection measures, including both land-based and online gambling. The second is to present shortcomings in eligible studies to highlight what type of information is needed in future studies.

Method: This systematic review included measures administered in both real-life settings and online. Twenty-eight studies fulfilled our inclusion criteria and had low or moderate risk of bias.

Results: The results showed that only two measures (long term educational programs and personalized feed-back) had an impact on gambling behavior. Follow-up period was short, and measures did not include gambling as a problem. The certainty in most outcomes, according to GRADE, was very low. Several shortcomings were found in the studies.

Discussion: We concluded that the support for preventive measures is low and that a consensus statement regarding execution and methods to collect and analyze data for preventive gambling research is needed. Our review can serve as a starting point for future responsible gambling reviews since it evaluated certainty of evidence.