Abstract
Target trial emulation is an approach to designing rigorous non-experimental studies by “emulating” key features of a clinical trial. Most commonly used outside policy contexts, this approach is also valuable for policy evaluation as policies typically are not randomly assigned. I discuss how to apply the target trial emulation framework in a policy evaluation context, with examples from a study investigating the effects of state medical cannabis laws on opioid and guideline-concordant non-opioid prescribing for chronic noncancer pain treatment among commercially-insured U.S. adults. The policy trial emulation framework includes the following 7 components: the exposure, the scientific question and estimand, the units, baseline (“time zero”), the treatment assignment procedure, the outcomes, and the analysis strategy. Policy evaluations that emulate a randomized trial across these dimensions can yield estimates of the causal effects of the policy on outcomes. Using the policy trial emulation framework to conduct and report on research design and methods supports transparent assessment of threats to causal inference in non-experimental studies intended to assess the effect of a health policy on clinical or population health outcomes.
Nicholas J. Seewald
Assistant Professor of Biostatistics
Assistant Professor of Biostatistics at the University of Pennsyvlania Perelman School of Medicine