In 2018, the Federal Ministry of Health (FMoH) of Nigeria and World Health Organisation (WHO) contracted Preston Associates to conduct a research on assessment of barriers to accessing health services for disadvantaged adolescents in Nigeria. The assessment was conducted over a one month period in Bayelsa, Borno and Sokoto States and the FCT.

The methodology as outlined in the WHO handbook for conducting an assessment on adolescent health services barriers was adopted by Preston Associates. This included literature review, quantitative data mining, and national and subnational qualitative data collection through Focus Group Discussions (FGDs) and Key Informant Interviews (KIIs) with adolescents and gate keepers.