All studies of contraceptive service interventions delivered to young people (more than 50% had to be aged over 25 years) in health care settings in developed countries were eligible for inclusion. All comparators were considered. Outcomes of interest were provision of contraception and/or advice (primary outcome), contraception use, pregnancy and behaviour modification (secondary outcomes).
Most studies were conducted in the United States; four were located in the United Kingdom. Health care settings varied. Many studies included a large proportion (or combination) of people with African American, Black, Hispanic and Latino origin. Types of service provided were new adolescent clinic services, outreach to existing services, advanced provision of emergency contraception, condom/general contraceptive provision and advice and services related to repeat pregnancy prevention. Descriptions of the intervention (including how it was delivered), comparators (where applicable) and study populations were generally lacking in detail. The main outcomes reported were pregnancy rates, and sexual behaviour or use of contraceptives measured by self-report. Other outcomes were reported in individual studies (such as sexually transmitted infections).
The authors did not state how many reviewers carried out the study selection.