The effect of active parental consent on the ability to generalize the results of an alcohol, tobacco, and other drug prevention trial to rural adolescents.

The authors report the effect of active parental consent on sample bias among rural seventh graders participating in a drug abuse prevention trial. Students obtaining active consent from their parents to complete the survey were of higher academic standing, missed fewer days of school, and were less likely to participate in the special education program at their school as compared to students who did not return a parental consent form. However, students with consent were not significantly different from students whose parents actively declined. The sample obtained under active parental consent represents students less at risk for problem behaviors than would have been obtained under passive consent procedures.