Background This is a supplemental report on tests of the long-term effects of universal preventive interventions conducted during middle school on 17–21-year-olds' prescription drug misuse.
Design/setting/participants Two randomized controlled prevention trials were conducted in public schools in the rural midwestern United States. Study 1 began in 1993, with 667 6th-graders; follow-ups with 12th-graders and 21-year-olds included 457 and 483 participants, respectively. Study 2 began in 1998 with 7th-graders (total sample across waves 2127); follow-ups with 11th- and 12th-graders included 1443 and 1212 participants, respectively.
Interventions In study 1, schools were assigned to the Iowa Strengthening Families Program (ISFP), Preparing for the Drug Free Years, or a control condition. In study 2, schools were assigned to the school-based Life Skills Training (LST) plus a revised ISFP, called SFP 10–14 (LST + SFP 10–14), LST-only, or a control condition.
Measurements Self reports of lifetime and past-year prescription drug misuse.
Findings In study 1, ISFP 12th-graders' past year narcotic misuse was significantly less than controls, as were ISFP 21-year-olds' life-time narcotic and barbiturate misuse rates. In study 2, LST + SFP 10–14 showed significant effects on life-time prescription drug misuse at the 11th-grade follow-up, while effects at the 12th-grade follow-up were marginally significant.
Conclusions Consistent with intervention effects on other substance use outcomes reported earlier, results suggest that universal interventions have potential for pubic health impact by reducing some types of prescription drug misuse among adolescents and young adults.