The state of child nutrition in Ethiopia: an umbrella review of systematic review and meta-analysis reports

Seven databases (PubMed, Embase, Scopus, Web of Sciences, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), and Google Scholars) were searched for SRM studies on child malnutrition and IYCF practices in Ethiopia, published from January 2015 to August 15, 2019. The search for malnutrition studies was focused on the four more prevalent undernutrition conditions of public health priority in Ethiopia; i.e., anemia, stunting, underweight, wasting, and underweight [1, 4]. The search for IYCF practice studies was focused on the child feeding indicators recommended by WHO/UNICEF. They were (a) early initiation of breastfeeding, (b) exclusive breastfeeding during the first 6 months, (c) continued breastfeeding up to 2 years and beyond, (d) dietary diversity, and (e) meal frequency. Thus, we specifically searched for SRM studies that reported on the magnitudes and determinants the 4 malnutrition conditions and the IYCF practice indicators mentioned above. For each condition, key search terms were identified and used to develop search strategies. The key terms and phrases used for searching studies on malnutrition were ‘anemia’, ‘stunting’, ‘wasting’, ‘underweight’, ‘risk factor’, ‘predictor’, determinant’, ‘meta-analysis’, ‘systematic review’, and ‘review’. The key terms and phrases used for searching studies on IYCF practice were ‘early initiation of breastfeeding’, ‘within one-hour breastfeeding’, ‘exclusive breastfeeding’, ‘duration of breastfeeding’, ‘complementary feeding’, ‘timely initiation of complementary feeding’, ‘feeding practices’, ‘dietary diversity’, ‘dietary quality’, ‘dietary frequency’, ‘meal frequency’, ‘minimum acceptable diet’, and ‘IYCF practices’. The literature search was done by two reviewers independently, with discrepancy resolved by consensus. A sample of the literature search strategy, PubMed search strategy, developed using a combination of MeSH terms and free texts is presented as a supplementary file (see Additional file 1). In addition to the systematic database searching, article searching was done using the reference list of the included studies and the ‘cited by’ and ‘related articles’ function of PubMed.

The search was restricted by language and period of publication. Only English language publications, done in the period 2015–2019, were eligible for inclusion. The time restriction was aimed to ensure the findings better reflect or relate to the current nutritional situation of the country. It was also for the magnitude and determinants of malnutrition might vary from time to time. For a study to be considered as systematic review or meta-analysis, it should have to meet the following predefined criteria: (a) presented a defined literature search strategy, (b) appraised included studies using a relevant tool, and (c) followed a standard approach in pooling studies and providing summary estimates. Studies were excluded due to any of the following reasons: (a) no report on the measures of interest for this study, (b) language other than English, and (c) narrative reviews, editorials, correspondence, abstracts, and methodological studies. When a study reported on more than one malnutrition conditions or IYCF practice indicators, all reports were extracted as long as they were reported following appropriate methods. The screening and selection of studies was conducted in two stages. First, title and abstract screening was done. Then, full-text reviewing was done.

Data from the included studies were extracted using a standardized data abstraction form, developed in excel sheet. For each study, the following data were extracted: (a) identification data (first author’s last name and publication year), (b) type of malnutrition condition or IYCF practice indicator assessed, (c) measure of magnitude (prevalence for malnutrition, coverage or level of practice for IYCF indicators) or measure of association (odds ratio or relative risk) with 95% confidence intervals, (d) number of studies included, (e) total number of samples included, (f) risk factors (determinant or predictor reported) for the main outcome variable(s) in the study, (g) publication bias assessment methods and scores, (h) quality assessment methods and scores, (i) data synthesis methods (random or fixed-effects model), and (j) the main conclusion of the study. When a study provided two different estimates (i.e., one based on random-effects model and the other based on fixed-effects model) on the same outcome, we extracted the estimate from random-effects model if the associated between-studies heterogeneity (Higgin’s I²) [25] was > 50% and estimate from fixed-effects model if the associated heterogeneity was < 50%.

The methodological quality of the included SRM studies was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) tool [26]. It consists of 11 questions that measure the quality of the approaches used for pooling the empirical studies included in the review and summarizing their estimates. The tool has been validated and frequently used for appraisal of the quality of SRM works. The quality scoring was done out of 11, with scores 8–11, 4–7, and < 3 indicating high, medium, and low qualities, respectively. The grading was done by two reviewers, with discrepancies resolved by discussion and consensus.

Both quantitative and qualitative approaches were used to summarize the estimates of the included studies. When two or more estimates were provided on the same topic, we presented the range of the estimates and also calculated a summary (pooled) estimate. The choice of the meta-analysis model was guided by the between-studies heterogeneity, which was assessed by Higgin’s I²-Statistics [25]. According to Higgins et al. I² < 49%, 50–75, and > 75% represents low, moderate, and high levels of heterogeneity, respectively. We intended to pool the estimates with fixed-effects models if the level of heterogeneity was < 50%. However, there was a high level of between-studies heterogeneity. Thus, the pooled (summary) prevalence estimates were calculated with the DerSimonian-Laird random-effects model, which accounts for both within-study and between-studies variations [27]. We intended to assess publication bias by visual inspection of funnel plots, Begg’s rank or Egger’s regression tests, as appropriate. However, it was not possible to assess publication bias as there were inadequate numbers of studies, which under-power any of these methods. A minimum of 10 studies is needed to evaluate publication bias [28]. Stata version 15.0 software (StataCorp, TX USA) was used for the quantitative analyses. A summary list of determinants of malnutrition and poor IYCF practices was prepared.

This study was done using data extracted from published studies. Thus, no study participants’ consent or ethical approval was needed.

The database search provided a total of 207 articles, of which 19 were eligible for full-text review. The remaining studies which were not SRM studies were excluded because the objective of this study was to include only SRM studies on the topics of interest. After full text reviewing, 8 studies were found eligible for inclusion. Additionally, one article was found by hand searching of the reference lists of the included studies. Thus, a total of 9 studies [4, 16‐23] were included in the current umbrella review. The study selection and screening process is shown in Fig. 1. We aimed to include anemia in this umbrella review, but no SRM report was found on it.

All SRM studies included in this review were observational in design. They included a total of 255 studies, providing a total sample of 214,458 under-5 children. The number of studies per SRM ranged from 14 (lowest) [23] to 70 (highest) [21]. The sample size per meta-analysis ranged 13,531 (lowest) [23] to 55,000 (highest) [21]. All studies were published from 2017 to 2019. The specific malnutrition conditions assessed by the SRM studies were stunting, wasting, and underweight. Two meta-analyses were done on the prevalence and the determinants of stunting, underweight, and wasting [4, 16]. The specific IYCF practice indicators assessed were exclusive breastfeeding, early initiation of breastfeeding, timely initiation of complementary feeding, dietary diversity, meal frequency, and minimum acceptable diet. Seven studies were done on both the magnitude and the determinants of IYCF practices [17‐23]. The overall characteristics of the included studies, including the topic they addressed, is shown in Table 1.

Table 2 shows the methodological quality of the included studies, evaluated using the AMSTAR tool for assessment of the methodological quality of SRM studies [26]. The quality scoring was done out of 11 points and ranged from 5 to 10, with a mean score of 7.8 points, indicating an overall moderate quality. The AMSTAR criteria more frequently satisfied across the studies were the ones about the assessment of publication bias and disclosure of conflict of interest. The AMSTAR criteria less frequently satisfied were the ones about inclusion and exclusion of studies and priori design.

The SRM studies on the magnitude and determinants of malnutrition included a total of 41 cross-sectional studies, covering a total sample of 57,757 under-5 children. The summary pooled prevalence of stunting, as defined by WHO height-for-age Z-scores below 2 standard deviations (SD) from the median of the reference population, was 42% (95%CI = 37–46%). The summary pooled prevalence of underweight, as defined by WHO weight-for-age Z-scores below 2SD from the median of the reference population, was 33% (95%CI = 27–39%). The summary pooled prevalence of wasting, as defined by WHO weight-for-height Z-scores below 2SD from the median of the reference population, was 15% (95%CI = 12–19%). The summary estimates of the prevalence of malnutrition are shown in Table 3.

The multi-dimensional factors, i.e. dietary and non-dietary factors, found linked to any of the three malnutrition conditions are shown in Table 4. Of these, the most frequently mentioned dietary factors founded linked to high risk of malnutrition (stunting, underweight, and wasting) were late initiation of breastfeeding, non-exclusive breastfeeding during the first 6 months, late initiation of complementary feeding, and low diversity and frequency of complementary feeding. Environmental factors found often associated with a high risk of malnutrition were an unimproved household water source, unimproved household toilet facility, and rural place of residence. Health factors found often associated with a high risk of malnutrition were childhood infection, home delivery, lack of immunization, family planning, antenatal and postnatal care, and poor utilization of micronutrient supplements like iron, vitamin A, and prophylaxis medications like deworming. There was significant variation in the magnitude of malnutrition by children’s sex and age; such that, there was a significant difference in the prevalence of stunting, wasting, and underweight by age and sex.

Seven SRM studies were done on the magnitude and determinants of suboptimal IYCF practice indicators. The specific IYCF indicators assessed were early initiation of breastfeeding, exclusive breastfeeding, timely initiation of complementary feeding, minimum dietary diversity, minimum meal frequency, and minimum acceptable diet. No SRM report was found on the duration of breastfeeding. The reported estimate of the level of early initiation of breastfeeding ranged from 61% (95%CI = 51–72%) to 67% (95%CI = 62–71%) and the pooled prevalence (calculated summary) estimate was 65% (65–55%); such that, two-thirds of children were fed with breast milk within the first 1 h after birth. The reported estimate of the level of exclusive breastfeeding ranged from 59% (95%CI = 54–65%) to 60% (95%CI = 56–65%) and the pooled prevalence (calculated summary) estimate was 60% (95%CI = 59–60%). The reported estimate of the level of timely initiation of complementary feeding ranged from 61% (95%CI = 52–70%) to 63% (95%CI = 57–68%) and the pooled prevalence (calculated summary) estimate was 62% (95%CI = 61–63%). The reported estimate of the proportion of children who met the minimum dietary diversity ranged from 18% (95%CI = 11–25%) to 23% (95%CI = 18–29%) and the pooled (calculated summary) estimate was 20% (95%CI = 19–21%). The summary estimates of the proportion of children who met the minimum meal frequency and the minimum acceptable diet were 56.0% (95%CI = 45–66%) and 10.0% (95%CI = 7–14%), respectively. Table 3 shows the reported and calculated (pooled) summary estimates of IYCF practices.

Seven SRM studies [17‐23] examined factors associated with sub-optimal IYCF practices and reported a number of health, sociodemographic, and environmental factors. Home delivery (i.e., instead of intuitional delivery), not attending antenatal care, postnatal care, and nutritional counseling services were the main health-related factors often found linked to sub-optimal IYCF practices. Low caregivers’ educational status, poor household socioeconomic status (low wealth category), low caregivers’ media exposure, paternal involvement in child’s care, household family size, and maternal breastfeeding experience were the main sociodemographic found linked to poor IYCF practices. Like the case of malnutrition, there was also significant variation in IYCF practices by children’s sex and age. Rural residence was the main environmental or household factor found linked to poor IYCF practices.