Table 3.

Data items to be extracted from included articles by study type and section

Study type	Section	Items
All	Study details	Study rationale, question(s), objectives, design, start date, end date, HPV vaccine initiation coverage, HPV vaccine completion coverage, factors found to be barriers for HPV vaccination, factors found to support or enhance HPV vaccination and factors found not to be associated with HPV vaccination.
	Study participants	Population description, US state or region, setting, inclusion criteria, exclusion criteria, method of selection, informed consent, number of participants, age, sex, clinical characteristics, social characteristics and Native American tribe.
	Funding and conflict of interest	Study funding sources and possible conflicts of interest.
Randomised controlled trial	–	Total number randomised, clusters, baseline imbalances, withdrawals and exclusions.
	Intervention and comparison group	Group name, number randomised to group, theoretical basis, duration of treatment period, timing, delivery, providers, cointerventions, economic information, resource requirements, integrity of delivery and compliance.
	Outcome	Outcome name, time points measured, time points reported, outcome definition, person measuring/reporting, unit of measurement, scales, is outcome/tool validated, imputation of missing data, assumed risk estimate and power.
Quantitative study	–	Method of follow-up, criteria for matching, exposure(s), outcome(s), confounder(s), effect modifier(s), measurement method, bias, statistical methods, missing data, outcome data, main results (point estimates and confidence intervals) and limitations reported and not reported.
Qualitative study	–	Qualitative approach, research paradigm, research characteristics and reflexivity, context, sampling strategy, data collection methods, data collection instruments, units of study, data processing methods, data analysis methods and main findings or themes.

HPV, human papillomavirus.