March marks four years since the WHO declared COVID-19 a global pandemic. In those four years, we’ve seen a rapid proliferation of laws enacted to, among other things, establish or block pandemic mitigation measures like vaccines and mask wearing. 

Nowadays, we are also seeing a growing number of studies attempting to assess the efficacy of such measures. These studies necessarily rely on legal data measuring the population’s “exposure” to these measures (for example, who has been affected by the laws, and for how long). Given the importance of and often politically charged nature of some of the interventions being studied, this month, we are sharing some key factors to consider when considering an evaluation study, particularly the legal data used in that study.