A multilevel analysis of trends and factors associated with early sexual initiation among adolescent girls and young women in Tanzania (2004/05-2022): Insights from four Demographic and Health Surveys

Background Early sexual initiation is a significant public health issue worldwide, particularly in Tanzania, where access to reproductive healthcare services is limited. It is closely associated to a higher risk of sexually transmitted infections, unintended pregnancies, poor birth outcomes, and psychosocial challenges. In Tanzania, limited research has focused on the long–term trends and associated factors. We examined the trends in early sexual initiation and explored both individual and contextual factors. Methods A pooled weighted sample of 13,179 adolescent girls and young women (AGYW) from four rounds of the Tanzania Demographic and Health Surveys was used in this study. Given the complex survey design, multilevel logistic regression model was employed to examine the trends and factors associated with early sexual initiation from 2004/05 to 2022. Adjusted odds ratio (AOR) with corresponding 95% confidence intervals (CI) were estimated to assess the strength and magnitude of the association. Results The overall weighted prevalence of early sexual initiation among AGYW in Tanzania was 16.3% (95% CI: 15.4–17.2). The trend of early sexual initiation increased significantly over time, from 14.4% in 2004/05 to 17.4% in 2022. At the individual level, factors such as increase in age (AOR = 0.84, 95%CI: 0.82–0.88), secondary education (AOR = 0.48, 95%CI: 0.38–0.61), literacy (AOR = 0.59, 95%CI: 0.51–0.69), employment (AOR = 0.87, 95%CI: 0.78–0.97), belonging to richest quantile (AOR = 0.61, 95%CI: 0.49–0.77) were associated with lower likelihood of early sexual initiation. At the community level, geographical zones were associated with higher likelihood of early sexual initiation. Conclusion The complex interplay of factors influencing early sexual initiation among AGYW in Tanzania reveals significant insights into the dynamics of education, socioeconomic status, and access to contraception.​ This can be intervened by adopting a multifaceted approach that encompasses education, socioeconomic empowerment, and tailored sexual health services, to more effectively mitigate early sexual initiation and foster healthier outcomes among AGYW.