A multistage random sampling technique was used to randomly select a cross-sectional study sample from a stratified listing of Egyptian primary school children aged 6-11 years, available at the time of study design. The study sample was determined based on the Egypt demographic health survey 2015. 18 All details of the selected schools in cities and villages in every single governorate were provided. The process was totally computerized. A total national sample of 33354 children was eligible for the study. The exclusion criteria were applied to 154 children leaving 33150 children as a final total sample to be included in the study. The study was carried out in a time frame from the beginning of January 2018 till the end of January 2020 at 59 primary schools. (Fig1) All types of schools (public, private and language schools) were included. All the socioeconomic strata were represented with weighted rural-urban representation. Two full-days’ workshop training was provided to field work team consisted, primary care physicians, pediatricians and nurses. Workshop training was conducted in each of the chosen 7 governorates of Egypt with providing more sessions to the teams of large regions. A pilot study of 50 children was designed to test all items of the project and also to test and standardize the capabilities of the involved team before proceeding to the main data collection. The field work included the school health supervisor, field team supervisors, doctors and nurses. The trained team made visits to all selected schools to complete a socio-demographic questionnaire, provide clinical examination and take body measurements. Children were sent to a chosen standardized laboratory center in every studied region to provide blood and stool sample to be examined.
Inclusion and exclusion criteria: Recruitment for the study was based on following inclusion criteria: Egyptian children of both sexes, aged from 6 to 11 years. The exclusion criteria were: children less than 6 years or more than 11 years old, children whose mothers/guardians or caregivers refused medical examination and investigation, receiving drugs known to cause short stature including chronic use of steroids, attention-deficit/hyperactivity disorder medications and anticonvulsants during the time of examination.
The mother/guardian or caregiver of each participating child was interviewed for potential determinants of child nutritional status including socio-demographic characteristics. Socioeconomic standard (SES) was assessed by updated scaling score of SES developed by Fahmy et al., 2015.19 Physical assessment and hemoglobin (Hb) level assessment were carried out to all children.
Measurements: Each child was instructed to stand on the center of a digital balanced scale (Beurer model GS 11, Germany) for measuring the weight and height assessed by Harpenden fixed stadiometer. Weight and height of each child was measured after calibrating to the nearest 0.1 kg and 0.1 cm, respectively. Horizontal Frankfurt plane with occiput, shoulder, buttocks, and heel touching the wall and the arms was down and relaxed. Each child was measured while wearing light clothes after removing shoes, belt, cap, hair style or any other material that could interfere with their actual height and weight. Body mass index (BMI) was calculated according to equation “(weight (in kg)/height squared (m2)”. Each of the three measurements was applied to WHO 2007 standard deviation growth charts.20 Anthropometric data on the height for age of children is used to quantify stunting. A child is stunted if their height for age Z score (HAZ) is <2 SD below the WHO median where the HAZ of child i is measured as HAZij = hij − h – j/ σj where hij is the height of child i in group j; where the group is based on the child’s sex and age. h − j is the median height of group j in the new WHO reference population and σj is the standard deviation value of group j in the new WHO reference population.20 Two dates were so important for the determination of the exact age at the time of measurement, the exact birth date (day/month/year) from an official document and the exact date of body measurements.
Laboratory investigations: Students were subjected for anemia screening using the HemoCue (HemoCue® Hb 201+) photometer. Hemoglobin concentration was read to the nearest 0.1 g/dL. Children with blood hemoglobin concentration level <11.5 g/dL were considered anemic according to age specific cut off levels established by WHO.21
Assessment of stunted children: Based on a past review of literature reported that the percentage of familial cause of stunting was 38%.22 Sample size has been calculated using the following equation: n = (z2×p × q)/ D2 at CI 95% and it was 356. To avoid drop out, 400 children with short stature were selected randomly for follow-up for a year. Twenty stunted children were missed during follow-up leaving 380 children. A specific approach inspired from consensus of European Society for Pediatric Endocrinology 2008 was followed to assess the etiological profile of stunting.8 A high specialty center was chosen to ensure presence of all required laboratory investigations and to avoid annoying the children by stressful transportation to many places. The initial evaluation included an accurate height measurement, detailed medical and nutritional history, birth weight, physical examination in addition to family history of short stature and pubertal age of both parents. Target height was calculated by the method of mid-parental height, the average of the mother’s and father’s height ± 6.5 cm (addition in boys or subtractions in girls).8 Then calculation of the growth velocity was performed after 1 year follow up of their height, which considered normal when it is at least 4 cm per year.23 All stunted children were investigated for bone age by radiography, and then assessed by radiologist according to published standards of Greulich and Pyle’s atlas of skeletal development. 24 Stunted children who had decreased growth velocity, symptoms of pathological disorders or severely stunted were investigated for: Stool analysis, complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), kidney function tests, liver function tests, serum electrolytes (calcium, phosphorus and alkaline phosphatase), bicarbonate, thyroid profile (Thyroid stimulating hormone (TSH), free thyroxin (T4)) and anti-tissue trans-glutaminase IgA and IgG (cases which tested positive were confirmed by endoscopic biopsy for celiac disease). After exclusion of other causes of short stature and systemic diseases with high clinical suspicion of GHD (height <-3 S.D from mean or height ≤2 S.D of the corrected mid-parental height and delayed maturation of bone), Growth hormone (GH) levels (after appropriate provocation test) and insulin like growth factor-1 (IGF-1) were investigated. GHD was diagnosed when GH peak level is under 10 ng/l and low IGF-1.23 Karyotyping was done for severe stunted female (<-3 SD.) without other causes even if no specific stigmata for Turner syndrome.8 Idiopathic cause was diagnosed when child with short stature, a subnormal growth velocity, delayed bone age, no other medical cause, and normal provocative test of growth hormone.25
Only data relevant to each child were entered in record then questionnaires containing socio-demographic data together with added laboratory investigations and findings of clinical examination were reviewed for completeness by the investigators. Dealing with any missing, unclear or incomplete data were done accordingly with the regional and field supervisor.
Patient and public involvement: This work aimed to screen the prevalence of short stature, malnutrion and anemia among Egyptian primary school children. To improve the relevance of research, research oriented to mothers and the public. The interviewed mothers recommended generalizing the screening over a large population and conducting it in the most crowded districts. Hence we asked them to tell every mother in their residence areas to communicate with their regional family health facilities and asking for simple growth monitoring of their children to early detect if there are any deviation in their children growth to be early corrected. A special day per governorate had been organized to thank all participants, disseminate the results and provide an in-depth group health education session. For other mothers, the main aim of the health education session was to correct wrong information and to build knowledge base for new mothers so they know well basics of proper nutrition.
Statistical analysis: Analysis of data was done using the Statistical Package for Social Sciences™ (Version 22.0; IBM Corp., Armonk, NY, USA). Frequency was used to describe the characteristics of the study population and to estimate the prevalence of underweight, overweight, obesity, anemia and short stature. Chi-square test was used for categorical variables. OR=ad/bc was applied to assess degree of risk where OR=1ànil, OR>1àrisky exposure, OR<1à Protective exposure. P-value <0.05 was set to be significant.