Impact of consent procedures on reported levels of adolescent alcohol use.

This study examined sample bias related to parental consent procedures in school-based survey research on alcohol-related behavior. Alcohol prevalence and severity of use estimates from a high school student survey using traditional-active parental consent (N = 1,429) were compared with estimates from 2 student surveys using alternative parental consent procedures (passive consent; N = 2,210 and N = 3,231). Traditional-active parental consent procedures resulted in underrepresentation of lifetime drinkers. Furthermore, traditional-active parental consent procedures resulted in lower levels of high-risk drinking, and this bias was most evident for Caucasians and both boys and girls. Findings accentuate the need for administrators, policymakers, and researchers to consider the impact consent procedure related bias may have on results and interpretation of findings from school-based substance use research.