Skip to Main Content
Everyone (Public)

YSPH EMD Seminar Series: "BEYOND INTERNAL VALIDITY: Field notes from the methodological borderlands"

The effect of smoking on risk of death is not the same as the effect of a smoking cessation intervention on risk of death – but we frequently act as if it is when considering policy. In this talk, I will describe the causal impact framework as a way of considering how to translate epidemiologic and scientific findings to decisions about public health policy. The causal impact framework considers first internal validity; then external validity; then population intervention impact; and (sometimes) cost-effectiveness analysis. The causal impact framework shows one way forward to making epidemiologic findings more relevant to implementation science, and likewise ways in which the epidemiologist can more effectively coordinate with both health behaviorists and health policy scientists.


  • UNC Gillings School of Public Health

    Daniel Westreich, PhD





Lectures and Seminars