A cross-sectional, multi-center study was designed in to determine the prevalence of malnutrition and related morbidity among hospitalized children under the age of five years in Abyan and Lahj governorates. The assessment of the nutritional status was measured by standardized anthropometry within the first 24 hours after admission or at attendance in outpatient clinic. Body mass index (BMI) and height/length <-2 standard deviation scores (SDS, WHO reference) are the primary outcome variables, frequency of gastrointestinal (diarrhea and vomiting) and respiratory tract infections and the period of stay are the secondary outcomes. Gender, Family income, mother's education, access to health facility, feeding practice and history of measles vaccination are the independent variables.
The study population are children at age 1-4 years who attend the health facility to seek care for certain health problem, mothers were interviewed while a trained nurse measured the weight and height and upper mid-arm circumference of the sick child.
From each governorate; five health facilities were selected. These facilities were: the main governorate hospital, two district hospitals and two health centers from two different villages in two different districts.
Data was collected through a group of enumerators and two field supervisors. Training of two days were conducted in Lahj (Al-Hottah city) in 28th of February, 2022 and in Abyan (Zunjibar city) in 3rd of March, 2022 where enumerators were trained about the questionnaire and the selection of the targeted children (sick children seeking care in the selected health facility within the age of 12-59 months). IT personal trained the enumerators about applying the KOBO toolbox and upload the digital questionnaire to their mobiles. This method is most effective method to make the research team monitors in daily basis the process of data collection.
Sample size calculation: The formula that is used to calculate the sample size is Danieal formula of cross-sectional study in infinite population.15
The following simple formula (Daniel, 1999) can be used:

where n = sample size, Z = Z statistic for a level of confidence (1.96) , P = expected prevalence or proportion, here is 10% based on the prevalence of malnutrition in Abyan,9 and d = precision (d= 2). Accordingly; the sample size will be:

We add 10% to avoid non response, so the final sample size was 864 + 86 = 950
The samples size will be distributed equally for Lahj and Abyan (475 from each) then was distributed proportional to health facility category (175 children from each governorate hospital, 100 children from each district hospital and 50 children from each health center.)
Anthropometric measurements:16
- Weight: Children were weighed standing on the weight scale to the nearest 0.1kg. For the children who could not stand, weight was measured in infant weight scale.
- Height/Length: Height and length of children were measured using height scale and recorded to the nearest 0.1cm. Children equal or less than 87.0 cm were measured lying down, and children greater than or equal to 87.0 cm were measured in standing position.
- MUAC: Mid-upper arm circumference measurements were made using a flexible and non-stretch tape. MUAC measurements was taken on the mid-point of the left upper arm. All the selected sick children in the aged 12-59 months were measured to the nearest 0.1 cm. The MUAC is interpreted as both for graduated and color labeled. Red color [MUAC <115 mm], and <125 mm] were considered a moderately
- malnourished. While the green color [MUAC ≥ 125 mm] were categorized as normal according to WHO classification.
Operational definition of the Outcome indicators:17
Wasting: Weight‐for‐height (wasting) provides the clearest picture of acute malnutrition
Moderate Acute Malnutrition (MAM) is identified by moderate wasting WFH ≤-2 z score and ≥-3 z‐score for children 0‐59 months (or for children 6‐59 months, MUAC <115 mm and ≥ 125mm). Table 1.
Severe Acute Malnutrition (SAM) is identified by severe wasting < -3 z‐score for children 12‐59 months (or for children 12‐59 months, MUAC <115 mm) or the presence of bilateral pitting edema.
Global Acute Malnutrition (GAM) is the presence of both MAM and SAM in a population. A GAM value of more than 10 percent indicates an emergency. If GAM is exceeding 15% it is considered critical while at 11-14% is severe GAM and if GAM at level of >5% and less than 10% is considered poor indicator.
Chronic malnutrition (Stunting) (Height-for-age Z score (HAZ)) The HAZ measure indicates if a child of a given age is chronically malnourished (stunted). The height-for-age index of a child from the studied population is expressed in Z-score (HAZ).
Table 1. Anthropometric measurements and indicators
Measurement
|
Indicator
|
Nutritional status
|
Weight-for-height index (W/H)
|
≥ -2 z-score
|
Normal nutrition status
|
(<-3 z-score and/or oedema and/or < 115 mm (MUAC)
|
Acute severe malnutrition (SAM)
|
WHZ ≥-3 and <-2
|
Acute moderate malnutrition (MAM)
|
MUAC
|
> or = 125
|
Normal nutrition status
|
< 125 and > or = 115
|
Acute moderate malnutrition (MAM)
|
< 115
|
Acute severe malnutrition (SAM)
|
Stunting (Height for Age -HAZ)
|
≥ -2 z-score
|
Normal nutrition status
|
3 z-score ≤ H/A < -2 z-score
|
Stunting (moderate)
|
< -3 z-score
|
Stunting (Severe)
|
The indicators:
1. proportion of wasting (MAM, SAM and GAM) among the hospitalized children in Lahj and Abyan
= Number of hospitalized children have MAM/ all hospitalized children under study
= Number of hospitalized children have SAM/ all hospitalized children under study
2. Proportion of stunting (Chronic malnutrition) among the hospitalized children in Lahj and Abyan
= Number of hospitalized children have stunting/ all hospitalized children under study