2.1. Study Design and Participants
STUNTING
This study is a part of the project “Ready to Use Supplementary Foods (RUSF) to Prevent Stunting Among Children Under Five Years in Kurram Agency”, a community-based non-randomized cluster-controlled clinical trial, undertaken from January 2018 to December 2020 in the low-resource rural areas of the tribal district Kurram of Khyber Pakhtunkhwa, Pakistan.In Pakistan, community health services at household levels are provided through the Lady Health Workers Program. One Lady Health Worker (LHW) is responsible for 100–150 households in her covered (assigned) area. In the current study, each LHW-covered area was considered an independent cluster. Furthermore, the clusters were refined using the expanded program on immunization (EPI) maps. Intervention and control clusters were selected based on natural segregation, especially prominent demarcation, to avoid contamination of the intervention between the study groups.A total of 80 matched clusters were included in the main trial, 40 each in the intervention and control arms. The overall sample size of the project was 7200 study participants from all four groups (pregnant and lactating women, 6–23 months, and 24–59 months children). Among the total participants, there were 1840 children between the ages of 24 and 59 months. In the current study, the impact of MNP supplementation was investigated in a sub-sample of 24–59-month-old-children. The trial is registered with ISRCTN 94319790.In this study, the MNP effect on plasma micronutrient level was evaluated in those households that had at least one child between 24 and 48 months old at the time of enrollment in both the intervention and control arms. Households with children aged 24–48 months were identified using the expanded program on routine immunization (EPI) maps in the respective areas. First, a line listing of the households in the clusters was performed and then systematic random sampling was used to select households containing at least one child aged 24–48 months. In the third step, one eligible participant from each household was included in the trial.