Summary of findings 2. Complex compared to simplified health education.

Comparison 2: complex compared to simplified health education
Population: adolescents Setting: Australia Intervention: multi‐component health educationa Comparison: simplified health education
Outcomes	Impact				№ of participants (studies)	Certainty of the evidence (GRADE)**
	Absolute effects* (95% CI)		Relative effect (95% CI)	Narrative results
	With simplified education	With complex health education
Uptake of hepatitis B vaccineb	756 per 1000	741 per 1000 (726 to 748)	RR 0.98 (0.96 to 0.99)	A complex multi‐component health education programme probably results in little or no difference in uptake of 3 doses of hepatitis B vaccine compared to simplified health education.	17,411 (1)c	⊕⊕⊕⊝ Moderated
CI: confidence interval; RR: risk ratio. *The anticipated absolute effect in the intervention group (and its 95% confidence interval) is based on the assumed likelihood of being vaccinated in the simplified health education group and the relative effect of the intervention (and its 95% CI). **GRADE Working Group grades of evidence: High certainty: this research provides a very good indication of the likely effect. The likelihood that the effect will be substantially different† is low. Moderate certainty: this research provides a good indication of the likely effect. The likelihood that the effect will be substantially different† is moderate. Low certainty: this research provides some indication of the likely effect. However, the likelihood that it will be substantially different† is high. Very low certainty: this research does not provide a reliable indication of the likely effect. The likelihood that the effect will be substantially different† is very high. †Substantially different = a large enough difference that it might affect a decision.

^a Health education kit with 4‐lesson structured multi‐component intervention that included: a resource fact sheet and assessment, an information video and questions designed to engage an adolescent audience, small group discussion, and an activity to locate resource information on the Internet.

^bThe lag‐time between delivery of the intervention and assessment of outcomes was not provided.

^cSkinner 2000 (randomised trial).
 ^d Downgraded one level due to study limitations, as the included study has an unclear risk of bias.