Report Publish Date: March 23, 2022
This research article describes the challenges of studying the population effects of social policies—such as policies related to education, income, immigration, labor, human rights, and employment and the regulation of alcohol, tobacco, and firearms—on health.
The authors say using epidemiological methods to study social policies’ impact on health presents several challenges for researchers. These include pinpointing and measuring what it means to be exposed to a policy, measuring the different ways a policy might affect different subgroups within a population, and having a large enough sample size to adequately measure effects.
“Promising tools to address these challenges,” the authors write, “can enhance both internal validity (randomization, front door criterion for causal identification, new estimators that address interference and practical positivity violations) and external validity (data-driven methods for evaluating heterogeneous treatment effects; methods for transporting and generalizing effect estimates to new populations).”
Addressing the social determinants of health through federal, state, and local policies could help improve health and reduce health disparities. But applied without understanding or close enough attention, these policies could also widen inequities, which makes it important for researchers to study their effects at a population level. Some researchers have begun to use the tools of epidemiology to try to understand how social policies impact health.
This article describes the challenges researchers have faced and how they might generate more accurate and helpful research.
The authors describe common approaches, what effects are measured and among whom, statistical considerations and data needs, and the problem of confounding bias. They describe methodological tools that could be used more often and more effectively.
“Researchers must navigate the tension between research questions of greatest interest and research questions that can be answered most accurately and precisely with the data at hand."
— Ellicott C. Matthay and M. Maria Glymour, University of California San Francisco
Better understanding how to study social policies could help researchers, policymakers, and others better design policies that improve health across populations by addressing social factors.
Purpose of Review: Epidemiologic research on the health effects of social policies is growing rapidly because of the potentially large impact of these policies on population health and health equity. We describe key methodological challenges faced in this nascent field and promising tools to enhance the validity of future studies.
Recent Findings: In epidemiologic studies of social policies, causal identification is most commonly pursued through confounder-control but use of instrument-based approaches is increasing. Researchers face challenges measuring relevant policy exposures; addressing confounding and positivity violations arising from co-occurring policies and time-varying confounders; deriving precise effect estimates; and quantifying and accounting for interference.
Summary: Common threats to validity in epidemiologic research play out in distinctive ways in research on the health effects of social policies. This is an active area of methodologic development, with ongoing advances to support causal inferences and produce policy-relevant findings. Researchers must navigate the tension between research questions of greatest interest and research questions that can be answered most accurately and precisely with the data at hand. Additional work is needed to facilitate integration of modern epidemiologic methods with econometric tools for policy evaluation and to increase the size and measurement quality of datasets.
Current Epidemiology Reports, March 23, 2022. https://dx.doi.org/10.1007/s40471-022-00288-7
This study and report was conducted and created by the following people.
