Authors, year | n | Study setting | Sample | Length of study | Intervention and intensity |
Randomised control trials | |||||
Palmgreen et al, 199116 | 207 | USA | Randomly recruited 18–22 year olds in Fayette County, Kentucky | Immediate post-test | Two anti-illicit-drug PSAs viewed twice over 10 min |
Fishbein et al, 200222 | 3608 | USA | Middle and high school students from 10 American schools | Immediate post-test | Six anti-illicit-drug PSAs of a total of 30 viewed once |
Harrington et al, 200318 | 338 | USA | 18–20 year olds recruited from a local college in Fayette County, Kentucky | 4 weeks | Four PSAs viewed once a week for 4 weeks for a total of 16 exposures |
Yzer et al, 200321 | 418 | USA | Students (mean age 14 years) from a middle school and a high school in Philadelphia | Immediate post-test | Two anti-marijuana PSAs, two anti-‘hard’ drug PSAs and an anti-drug testimonial, two anti-marijuana and two anti-‘hard’ drug PSAs, or four anti-‘hard’ drug PSAs once |
David et al, 200623 | 535 | USA | 7th- and 12th-grade students from 3 schools in Philadelphia | Immediate post-test | 10 PSAs viewed once; participants then randomised to engage in online chatting immediately following viewing |
Czyzewska and Ginsburg, 200720 | 229 | USA | Undergraduate freshmen aged 18–19 in San Marcos, Texas | Immediate post-test | 15 anti-marijuana or 15 anti-tobacco ads once |
Wagner and Sundar, 200819 | 65 (Trial 1); 28 (Trial 2) | USA | High-school seniors aged 17–18 in Pennsylvania (Trial 1). Undergraduate students in Pennsylvania (Trial 2). | Immediate post-test | Four anti-illicit-drug PSAs once |
Observational | |||||
Palmgreen et al, 200224 | 3174 (Fayette County); 3197 (Knox County) | USA | Public school students aged 12–16 in Knox County, Tennessee and Fayette County, Kentucky | 32 months | 70% of sample exposed to a minimum of three anti-illicit-drug PSAs per week for 4 months |
Orwin et al, 20044 | 3142 | USA | Youth aged 9 to 18 surveyed through the National Survey of Parents and Youth | 5 years | Average of 2.5 anti-illicit-drug PSAs viewed by sample over 58 months |
Pennay et al, 20065 | Pretest: 1400 Post-test: 1490 | Australia | Youth aged 13–20 recruited into a national survey of youth | 1 year | Three anti-illicit-drug PSAs over 9 weeks. Intensity not reported. |
Palmgreen et al, 200725 | 4795 (Fayette County); 4803 (Knox County) | USA | Public school students aged 13–17 in Knox County, Tennessee and Fayette County, Kentucky | 48 months | Four antimarijuana PSAs. Intensity not reported. |
PSA, public-service announcement.