Sample size determination and sampling
SECONDARY
The sample size was determined using G-Power statistical software version 3.1.5. The assumption for the sample size was that two population proportions have an estimated prevalence (P1) of modern contraceptive use among secondary school students of 57% [However, only 224 participants who were currently sexually active adolescents were included in the analysis. The study included 273 sections from six schools, with 81 sections from grade nine, 76 from grade 10, 64 from grade 11, and 52 from grade 12. Using identification numbers, the number of research participants in each school and grade level was determined and allocated proportionally based on the population size.