Online Program

Advancing the state of research designs used in injury control policy evaluation

Monday, November 4, 2013 : 10:45 a.m. - 11:00 a.m.

Alexander C. Wagenaar, PhD, Emory University Rollins School of Public Health, Atlanta, GA
Scott Burris, JD, Beasley School of Law, Temple University, Philadelphia, PA
Empirical evaluation of injury control laws has supported dramatic prevention gains in the past decades. Studies have demonstrated beneficial effects in reduced injury, and facilitated diffusion of effective policies. Nevertheless, evaluations continue to use research designs characterized by limitations on internal validity—the strength of confidence in a causal interpretation of observed effects. Drawing on a new book on Public Health Law Research: Theory and Methods, this presentation describes and illustrates the use of experimental and quasi-experimental designs in the evaluation of injury control laws. Few policy evaluators consider random assignment to treatment conditions, since scientists never control passage and implementation of laws and regulations. In fact, there are instances in which new rules may be implemented in a way that allows experimental evaluation. Moreover, experimental methods may be used in the “laboratory” to experimentally test the mechanisms of a law's effects. In natural experiments where random assignment is not possible, there are many design elements that, when combined in a single study, produce study designs that match or sometimes exceed the validity of RCTs. Such elements include: long time-series spanning decades; high time-resolution measures (daily/weekly/monthly); multiple comparison groups, sites, measures; hierarchically nested levels of comparisons; and dose-response studies. Renewed calls for evidenced-based policy making are presenting new opportunities for advancing the use of law to advance injury prevention. Improving the science of policy evaluation by strengthening research designs will help advance public health policy's effectiveness.

Learning Areas:

Public health or related laws, regulations, standards, or guidelines
Public health or related public policy
Public health or related research
Social and behavioral sciences

Learning Objectives:
Identify common design challenges in the evaluation of legal interventions to prevent injury. Describe the feasibility of experimental designs with randomization in the policy context. Demonstrate the robustness of quasi-experimental designs that use multiple design elements to strengthen causal inference.

Keyword(s): Research

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am the Associate Director of the Public Health Law Research program. I have published a book, numerous book chapters, and over 160 scientific articles on social epidemiology, public health policy, legal evaluations, community intervention trials, alcohol and tobacco studies, violence prevention, traffic safety, and injury control.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.