Medical marijuana laws, substance use treatment admissions, and the ecological fallacy

Abstract

Meinhofer¬†et al.¬†1¬†analyzes administrative data from state medical marijuana laws and substance use treatment admissions in an ecological study design to show that medical marijuana laws are associated with state-level increases in marijuana, alcohol and cocaine treatment admissions among pregnant women. While these findings are provocative, the utility of ecological analyses in assessing the effects of medical marijuana use is severely limited and this studyâs results could reflect bias, rather than an individual-level effect.