Effect of Hygiene and Menstrual Hygiene Interventions on Learning and Psychosocial Wellbeing in Madagascar

140 secondary schools were randomly assigned to one of four arms: (1) control, (2) infrastructure only, (3) sensitization + free sanitary pads, or (4) the full combined package. Outcomes are assessed via girls' surveys, teacher/director surveys, and school-level surveys at baseline (Oct 2024), midline, and endline.

This registration draws on two overlapping analytic samples. The first is the full 140-school evaluation sample (35 schools/arm; approximately 3,080 girls, ~22/school), used for the cognitive/academic composite, self-reported psychosocial well-being (GAD-7, PHQ-9), and health outcomes that do not require biospecimen collection or laboratory processing - self-reported infectious disease symptoms, mid-upper-arm circumference (MUAC), and self-reported urinary tract infection. These are collected during the social-science endline survey (May-June 2026), concurrent with the parent trial's learning and psychosocial data collection. The second is a 80-school biomarker subsample (approximately 20 schools/arm; ~1,360 girls, ~17/school), used specifically for salivary cortisol and blood-based C-reactive protein (CRP) drawn from a venipuncture. These outcomes require biospecimen collection, cold-chain transport, and laboratory assay, and are therefore restricted to the subset of schools logistically accessible for that purpose. They are collected at a separate endline health/biomarker visit at a Basic Health Center (July-August 2026, ~19 months post-baseline).

This registration covers the biomarker outcomes component of the trial, with data collection and analysis completing by approximately December 2026; the broader parent Kilonga 2 trial (registered with the AEA RCT Registry, AEARCTR-0014423) has a longer overall completion date of December 2027, covering the full set of learning and psychosocial endpoints. The biospecimen collection protocol includes additional biomarkers, cortisol and C-reactive protein, as registered secondary outcomes.

This trial was registered with ClinicalTrials.gov retrospectively, after participant enrollment had already begun. At inception (October 2024), the study was designed and IRB-approved (Paris School of Economics IRB #2024-046, approved September 17, 2024) as a social science evaluation focused on learning outcomes, and was prospectively registered with the AEA RCT Registry (AEARCTR-0014423) on September 23, 2024. Registration with ClinicalTrials.gov was initiated upon expanding the study to include health-related biomarker secondary endpoints, in order to comply with ICMJE requirements for biomedical journal publication. The Pre-Analysis Plan covering these health endpoints will be timestamped on the Open Science Framework prior to the start of health data collection in July 2026.

Inclusion criteria

• Girl identified in the Kilonga 2 evaluation sample (randomly selected during the December 2024-January 2025 baseline from class registers across the 140 participating schools); participants were 11-20 years old at baseline enrollment and are approximately 12-21 years old at the time of endline/health-outcomes data collection (May-August 2026)
• Full evaluation sample (n~3,080; ~22 girls/school): all girls in the Kilonga 2 sample across the 140 schools are eligible for the cognitive, self-reported psychosocial, and non-biospecimen health outcomes, collected at the social-science endline.
• Biomarker subsample (n~1,360; ~17 girls/school): girls attending one of the 80 schools selected for the health biomarker subsample (logistically accessible for biospecimen collection and cold-chain maintenance) are additionally eligible for salivary cortisol and blood-based C-reactive protein outcomes.
• Informed consent obtained from parent/legal guardian, and assent obtained from the participant herself

Exclusion criteria

• Adolescents not meeting the inclusion criteria above
• Adolescents (or their parent/legal guardian) who refuse to participate or who withdraw consent/assent at any time
• Adolescents for whom sample collection is judged impossible or contraindicated at the time of collection (e.g., health status precluding collection)