Sexual Health

Baseline sociodemographic and sexual and reproductive health characteristics of the AdSEARCH adolescent cohort study participants in rural Bangladesh: a cohort profile.

TL;DR

The AdSEARCH adolescent cohort study presents baseline sociodemographic and sexual and reproductive health characteristics of 2713 adolescents in rural Bangladesh, documenting gender differences in school attendance, income-generating activities, depression prevalence, SRH knowledge, gender attitudes, and violence exposure.

Key Findings

The AdSEARCH cohort enrolled 2713 adolescents from the Baliakandi Health and Demographic Surveillance System in rural Bangladesh, organized into five sub-cohorts by age and sex.

  • The cohort covered three age groups from girls and boys: girls aged 12, 14, and 16 years; and boys aged 14 and 16 years.
  • The study was run by the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b).
  • Seven rounds of data were collected at 4-month intervals over a 2-year follow-up period.
  • The cohort was drawn from the Baliakandi Health and Demographic Surveillance System.

The majority of adolescents were attending school, with school dropout rates higher among boys.

  • Approximately 90% of adolescents were attending school at baseline.
  • School dropouts were reported to be higher among boys compared to girls.
  • This gender disparity in dropout rates was noted as a distinguishing sociodemographic characteristic of the cohort.

Around 17% of adolescents were involved in income-generating activities, with this participation predominantly among boys.

  • Approximately 17% of all respondents reported involvement in income-generating activities.
  • Income-generating activity was described as 'mostly' a male phenomenon in this cohort.
  • This finding reflects a gender-differentiated economic participation pattern among rural Bangladeshi adolescents.

The mean age of menarche among girls in the cohort was 12.2 years.

  • This figure was derived from the female participants across the three girl cohort age groups (12, 14, and 16 years).
  • Age of menarche was reported as part of the sexual and reproductive health baseline characteristics.
  • This metric provides a biological reproductive health benchmark for future longitudinal follow-up analyses.

Overall, 6% of adolescents had major depressive disorder at baseline, with prevalence increasing with age.

  • The overall prevalence of major depressive disorder (MDD) was 6% across the full cohort.
  • MDD prevalence was observed to increase with age among adolescents.
  • This finding highlights a mental health burden within this rural adolescent population.
  • MDD was assessed as part of the broader SRH characterization of the cohort.

Gender differences were evident in knowledge about conception and contraception among adolescents.

  • Knowledge about conception and contraception differed by gender at baseline.
  • Specific knowledge levels and the direction of gender differences are noted but exact percentages are not provided in the abstract.
  • This finding forms part of the SRH knowledge baseline for longitudinal tracking of change over 2 years.

Egalitarian attitudes towards social norms and gender roles were substantially higher among girls than boys.

  • 52% of girls held egalitarian attitudes towards social norms and gender roles.
  • Only 11% of boys held egalitarian attitudes towards social norms and gender roles.
  • This represents a large gender gap of approximately 41 percentage points in egalitarian attitudes.

The majority of adolescents reported experiencing some form of violence or bullying, with social/verbal bullying being most common.

  • 43% of adolescents reported experiencing social/verbal bullying.
  • 38% reported experiencing physical violence.
  • 4% reported experiencing cyberbullying.
  • Multiple forms of violence exposure were documented as part of the baseline SRH characterization.

What This Means

This research describes the starting characteristics of a large group of 2,713 adolescents living in rural Bangladesh who are being followed over two years as part of a study on sexual and reproductive health. The young people were grouped by age and sex — girls aged 12, 14, and 16, and boys aged 14 and 16 — and researchers collected information from them seven times over the two-year period. At the start of the study, 90% were in school, though boys were more likely than girls to have dropped out, and about 17% were already earning income, mostly boys. Girls began menstruating at an average age of 12.2 years, and 6% of all adolescents showed signs of major depression, with older adolescents more affected. The study also found notable differences between boys and girls in several areas. Girls were far more likely than boys to hold egalitarian views about gender roles — 52% of girls compared to only 11% of boys. Boys and girls also differed in what they knew about conception and contraception. Additionally, violence was common in this group: 43% reported verbal or social bullying, 38% reported physical violence, and 4% reported cyberbullying, painting a picture of significant adversity faced by rural Bangladeshi adolescents. This research suggests that adolescents in rural Bangladesh face a complex mix of challenges including school dropout, early entry into work, mental health struggles, and widespread exposure to violence, all of which vary considerably by gender. Because this is a longitudinal study — meaning the same young people will be followed over time — future analyses will be able to track how these factors change as adolescents grow older and how they influence sexual and reproductive health outcomes. The findings are intended to inform health policies and programs designed specifically for adolescents in Bangladesh.

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Citation

Alam A, Shiblee S, Rana M, Sheikh S, Rahman F, Sathi S, et al.. (2025). Baseline sociodemographic and sexual and reproductive health characteristics of the AdSEARCH adolescent cohort study participants in rural Bangladesh: a cohort profile.. BMJ open. https://doi.org/10.1136/bmjopen-2025-102156