Data collection
malaria
MALARIA
Trained study staff collected data from adolescents at school, whose parents had provided consent and who had themselves provided assent to participate. Data collected included demographic and dietary surveys, and anthropometric measurements. A structured questionnaire comprising questions on socio-demographics, household possessions, physical activity (International Physical Activity Questionnaire for Adolescents), water, sanitation and hygiene practices (WASH), food frequency and preferences, and socio-emotional development (Strengths and Difficulties Questionnaire, Child Outcomes Research Consortium) was used to collect data.In addition, a finger prick was used to assess hemoglobin levels and malaria status. Hemoglobin status was assessed using a portable battery-operated photometer (Hemocue 201 + machine) [Anthropometric measurements (height and weight) were taken as double measurements, according to WHO standards. Height was measured using a Seca stadiometer (ShorrBoard, USA) and recorded to the nearest 0.1 cm. During the measurement, participants stood in the Frankfurt anatomical position. Shoes were taken off and prominent body parts (occipital, shoulder, buttocks and heel) touched the stadiometer. Weight was measured with the Seca 874 weighing scale (Seca, Germany) and recorded to the nearest 0.1 kg. Heavy clothes and shoes were taken off. Both the weighing scale and length board were calibrated daily.The questionnaire was prepared in English and translated to Swahili and back translated to English to ensure consistency. It was piloted in two schools out of the selected schools. Twenty-four enumerators, three laboratory personnel, and one supervisor participated in the data collection. The data collection team received training for three days on the objectives and methodology of the study and the process of data collection by the principal investigator. Data collectors were supervised throughout the activity and daily meetings were held to monitor progress. Daily data cleaning and checks were done to check for accuracy.