Study design and Study Setting
A retrospective cohort study was conducted at Yekatit 12 hospital medical college, Addis Ababa. It is one of few hospitals with an established nutrition therapy unit. Children affected by SAM go through initial screening in regular OPD or emergency unit. Depending on the initial assessments and after cross checking their condition against admission criteria, they will be admitted to the nutritional rehabilitation center, where they receive appropriate treatment and follow up.
The Hospital uses a standardized national management protocol of severe acute malnutrition. According to the protocol, all SAM cases with co-morbidities and poor appetite shall be admitted in the SAM inpatient management section. Whereas those diagnosed for SAM without co-morbidities and with good appetite will be linked to the outpatient management section. After completing the inpatient management, those who satisfy the discharge criteria will be directed to community based feeding program for further follow up (14).
Study population and sampling technique
The study population encompasses 6-59 months old SAM affected children admitted at the Yekatit 12 hospital inpatient unit from 2013 to 2016. The following inclusion and exclusion criteria have been adopted accordingly.
Inclusion criteria: Since at the time of the study Ethiopia didn’t adopt the latest cut off points which is MUAC <115mm, all the criteria are used from the 2007 Ethiopian National Guideline for Management of SAM. Accordingly, children within the age range of 6 months to 5 years that fulfill the following criteria were included in the study.
- Weight-for-height/length ratio < 70% of median or less than – 3Z- score
- MUAC < 110 mm with Length >65cm
- Presence of bilateral pitting edema with complications or a fail in the appetite test (14)
Exclusion criteria: Drop out and transfer outs were excluded in this study because their outcomes couldn’t be traced.
The sample size was calculated using EPI info version 22.214.171.124 for a cohort study design. Based on other related studies conducted in a similar context, variables which are significantly associated with undesirable treatment outcomes were identified and were used to calculate the sample size. The computation was conducted based on the following assumptions; 95% confidence level with 80% power and an allocation ratio of 1:1 as unexposed to exposed ratio. Based on these assumptions, the computed optimal sample size (taking the largest) was 152 for each group (Table 1).
The study variables were categorized as dependent and independent variables. The reason in doing so was to assess which independent variables significantly affect the magnitude of the dependent variable.
The dependent variable was undesirable outcome which includes death, non-respondent and failure to respond. On the other hand, socio-demographic and admission characteristics, anthropometry, type of malnutrition, comorbidities, vaccination and breast-feeding status were considered as independent variables.
For a child admitted with SAM, the management procedure consists of 3 phases (phase1, transition and phase 2). Children were assessed based on the Ethiopian national management protocol for SAM which is in accordance with the WHO procedure for management of SAM. The ten steps of the WHO SAM management include: treat/prevent hypoglycemia, treat/prevent hypothermia and dehydration, correct electrolyte imbalance, treat/prevent infection, correct micronutrient deficiencies, start cautious feeding ,achieve catch up growth , provide sensory stimulation and emotional support and prepare for follow up after recovery.
If a child either failed to regain appetite, lose edema by day 4 after admission, gain more than 5g/kg/d by day 10 after admission or failed to gain more than 5g/kg/d for 3 successive days during phase 2 while being on treatment, he/she was termed as failure to respond. And those that had not reached the discharge criteria after 40 days in the inpatient unit were defined as non-responders.
Patients who were discharged after reaching the discharge criteria (weight for height/length > 85% of median on more than one occasion or no edema for 10 days and a target weight gain reached for two consecutive measurements, if the child is admitted with MUAC) were considered as cured. Whereas those who discontinued treatment or disappeared from nutritional rehabilitation ward before completing treatment were defined as dropouts. Patients whose treatment results are unknown due to transfer to another health facility were defined as transfer outs. And those patients who died from any cause during the course of treatment were defined as dead.
In this study, undesirable outcomes were considered to be: death, non-responder and failure to respond (drop out and transfer outs were excluded in this study because their outcomes couldn’t be traced).
Certain prominent comorbidities were selected under the assumption that it is highly probable that they might be correlated to SAM. This assumptions are based on findings on other studies. The comorbidities considered are the presence of shock, anemia, pneumonia and HIV.
Data collection procedure and data quality assurance
Inpatient register book of the Yekatit 12 Hospital which contained the admission, patient history and discharge information was used as the main data source. Children diagnosed with SAM within the study time frame were selected. Then, each patient record was examined based on the inclusion and exclusion criteria. Records which were complete and that fulfilled the inclusion criteria were included in the study. The data examination and selection producer was carried out by the principal investigator based on checklist adopted from the world health organization guideline for inpatient treatment of SAM 2003 manual.
Testing of the checklist for its completeness and clarity was done before the actual data collection took place and modifications were applied as needed.
Data management and analysis
Following the completion of data collection, the data were categorized and coded. Then, the collected data were entered into a computer using EPI-Info software program. The data entry and cleaning were done using EPI-Info 126.96.36.199 version which was later on exported to SPSS version 20.0 statistical software packages for analysis.
In this study, the dependent variable was undesirable outcome (which incorporates the variables, death, non-responder and failure to respond). Children with undesirable outcome were considered as event and all other outcomes were censored. Finally, the outcome of each subject was dichotomized into censored or undesirable outcome.
Descriptive statistics was used to summarize and describe the data. Regarding survival analysis, Life table analysis was used to estimate the cumulative proportion of survival among children with SAM at different time point. Kaplan Meier survival curve together with log-rank test was fitted to test for the presence of difference in undesirable outcome among groups; the time variable was assumed to be the time to the occurrence of undesirable outcome measured from admission to date of an event. Variables at P-value of <0.25 in the bivariate analysis were included in the final Cox regression analysis to identify the independent predictors of undesirable outcome. In addition, Crude and adjusted hazard ratio with their 95% Confidence Interval (CI) were estimated and summarized. The study result was also compared with the minimum standard presented by the “Sphere” project.