Table 2.
Number of included papers by health area
| Health area | Number of papers (% of total included) | Total participant number | Overall effectiveness ratinga | Overall quality appraisal ratingb |
|---|---|---|---|---|
| Sex education/HIV prevention | 23 (31.5%) | 51,354 | Suggests ineffectiveness | Medium |
| Healthy lifestyles (exercise, nutrition, oral health, health information) | 17 (23.3%) | 21,172 | Mixed effectiveness | High |
| Alcohol, smoking, substance use | 16 (21.9%) | 32,488 | Mixed effectiveness | Medium |
| Mental health (incl. suicide prevention) | 6 (8.2%) | 6712 | Suggests effectiveness | Medium |
| Asthma | 5 6.8%) | 2136 | Suggests effectiveness | Medium |
| Disease prevention (including HIV, cervical cancer and hepatitis) | 4 (5.4%) | 8467 | Suggests effectiveness | Medium |
| Bullying | 2 (2.7%) | 1607 | Mixed effectiveness | High |
aThe proportion of ‘effective’ studies was calculated for each health area and then assigned an overall effectiveness rating based on our scoring thresholds in Table 1 (e.g. if ≥ 60% studies in a health area demonstrated effectiveness this health area was given an overall rating of effective)
bThe average quality rating was calculated across all papers in health area, 0–1 indicating poor quality, 2–3 indicating average quality and 4–5 indicating high quality