The role of parental consent in adolescent substance use research

J Adolesc Health. 2008 Feb;42(2):192-7. doi: 10.1016/j.jadohealth.2007.07.011. Epub 2007 Nov 7.


Purpose: The objective of our study was to assess the effects of requiring parental consent upon study participation and self-reported substance-related problems among 14-18-year-olds.

Methods: This was a secondary analysis of combined data from two similar studies of adolescent substance use that recruited participants from the same adolescent clinic at Children's Hospital Boston. Study 1 waived parental consent, whereas Study 2 required parental consent. The combined dataset included demographic characteristics and Car, Relax, Alone, Forget, Friends, Trouble (CRAFFT) study screening test responses. The CRAFFT is an orally administered screen that yields a score from 0-6 and that has been shown to be a valid and reliable measure of risk for substance-related problems.

Results: The participation refusal rate in Study 1, where consent was waived, was 19.7% (132 of 670 eligible individuals) and in Study 2 (243 of 411 eligible individuals), where consent was required, it was 59.1% (p < .0001). Participants did not differ significantly with respect to gender and age but did differ by self-identified race/ethnicity between the two studies. Because the CRAFFT score distributions were highly skewed, we used the nonparametric Mann-Whitney U test for differences in mean rank. The mean rank in Study 1 was significantly higher than in Study 2 (mean rank 362 vs. 325, p = .02). After controlling for age, gender, and race/ethnicity, the adjusted proportional odds ratio for a one-point increase in CRAFFT score was 1.47 (CI 1.03, 2.10) for Study 1 compared with Study 2.

Conclusions: The research requirement of parental consent may result in substantial self-selection bias towards a lower risk sample.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Age Distribution
  • Biomedical Research
  • Cross-Sectional Studies
  • Female
  • Humans
  • Incidence
  • Male
  • Massachusetts / epidemiology
  • Parent-Child Relations
  • Parental Consent
  • Patient Participation
  • Probability
  • Sex Distribution
  • Statistics, Nonparametric
  • Substance Abuse Detection / methods*
  • Substance-Related Disorders / diagnosis
  • Substance-Related Disorders / epidemiology*