Watson‐Jones 2012.

Methods	Cluster‐randomised trial in Tanzania
Participants	Participants: girls enrolled in primary school grade 6 or girls born in 1998. Number enrolled: 134 schools (60 urban government, 60 rural government, and 14 private) and 5532 eligible girls Study population: in the city of Mwanza and the neighbouring district of Misungwi in northwest Tanzania, 134 primary schools were randomly assigned to class‐based (girls enrolled in primary school grade (class) 6) or age‐based (girls born in 1998; 67 schools per arm) vaccine delivery.
Interventions	Intervention: provision of HPV vaccine through a class‐based strategy (targeting girls in school class 6). Comparison: provision of HPV vaccine through an age‐based strategy (targeting girls born in 1998). Description: teachers, parents, and girls in the target vaccination group were provided with verbal and written information about HPV vaccination through school, parent, and community meetings; leaflets and posters; radio messages; and through community drama troupes. Duration: 12 months Vaccine target: HPV Disease targeted: cervical cancer Number of doses: 3 doses
Outcomes	HPV vaccine uptake Adverse events
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No description.
Allocation concealment (selection bias)	Low risk	Allocation done by an independent statistician.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	This was cluster randomised and the outcome is an objective measure.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	HPV uptake is an objective outcome measure.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up.
Selective reporting (reporting bias)	Low risk	No selective reporting.
Other bias	Low risk	No other bias observed.