摘要：Systematic reviews are generating valuable scientific knowledge about the impact of public health laws, but this knowledge is not readily accessible to policy makers. We identified 65 systematic reviews of studies on the effectiveness of 52 public health laws: 27 of those laws were found effective, 23 had insufficient evidence to judge effectiveness, 1 was harmful, and 1 was found to be ineffective. This is a valuable, scientific foundation—that uses the highest relevant standard of evidence—for the role of law as a public health tool. Additional primary studies and systematic reviews are needed to address significant gaps in knowledge about the laws’ public health impact, as are energetic, sustained initiatives to make the findings available to public policy makers. Law is a traditional public health tool that has made vital contributions to the major public health achievements of the 20th century. Examples include school immunization laws that helped reduce the rates of infectious disease and tobacco control laws that helped reduce the rates of chronic disease. 1 Indeed, many, if not all, government public health endeavors rely on laws crafted to address specific health conditions or risk factors (“interventional” public health laws), laws that create and empower public health agencies and jurisdictions (“infrastructural” public health laws), or the general police powers of state governments. In addition, many laws not designed principally for public health objectives nonetheless have public health consequences (e.g., taxation and education laws). While potentially powerful legal tools for public health, these latter laws are not considered here. Policy makers weigh many factors as they consider adopting and promoting public health laws. A central question—especially in this time of emphasis on evidence-based practice and policy—is whether there is sound scientific evidence that a given public health law is effective. The number of peer-reviewed publications reporting on the impact of interventional public health laws is growing, as is the number of systematic reviews and meta-analyses of such primary studies. 2 However, this body of scientific knowledge, although potentially of great value, to date has not been summarized and made readily accessible to policy makers. We begin to address this gap. Systematic reviews and meta-analyses apply the most sophisticated methodologies currently available to assess the findings of multiple primary studies focused on a given intervention. 3 Systematic reviews have been defined as review[s] of a clearly formulated question that use[s] systematic and explicit methods to identify, select, and critically appraise relevant research, and to collect and analyze data from the studies that are included in the review. 4 Often considered a subset of systematic reviews, meta-analyses are quantitative statistical analyses … applied to separate but similar experiments of different and usually independent researchers and that involve[s] pooling the data and using the pooled data to test the effectiveness of the results. 5 For the sake of simplicity, we use the term “systematic review” for both. We report on a survey of systematic reviews of peer-reviewed primary studies of individual interventional public health laws. It is thus a report on the highest-quality scientific evidence currently available on the effectiveness of such laws. In addition, we identified recommendations contained in those reviews for future research on interventional public health laws.
