To evaluate physical health status of left-behind children in some rural areas of China, and to provide evidence-based medical evidence for left-behind children′s health care services.

Cross-sectional studies about physical health status of left-behind children in China were searched from China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), VIP, and Wanfang Database. Retrieval time was set from the inception of each database to August 2019. Two researchers independently screened the studies according to the inclusion criteria and exclusion criteria of this study, and evaluated the quality of each literature and extracted data from each literature. After cross-checking by these two researchers, Meta-analysis of physical health status of left-behind children in some rural areas of China was conducted by RevMan 5.3 software. The Agency for Healthcare Research and Quality (AHRQ) recommendation for cross-sectional study analysis criteria was used to evaluate the methodological quality of included literature. I² test was used for the heterogeneity analysis among the studies. Fixed effect model Meta-analysis was used when P≥0.10 and/or I²≤50%, and random effect model Meta-analysis was used when P<0.10 and/or I²>50%. The evaluation indexes of health situation of left-behind children included detection rate of nutritional diseases (nutritional anemia, malnutrition and zinc deficiency) and detection rate of growth retardation, and rate of underweight.

①A total of 9 articles involving 14 588 cases of children were included. They were from Anhui, Guangdong, Henan, Hubei, Hunan, Shandong, and Shaanxi Province, respectively. According to the definition of left-behind children in this study, they were divided into left-behind children group (n=8 010) and non-left-behind children group (n=6 578). ②The methodological quality evaluation results of included studies showed that there were 1 low-quality study, 5 medium-quality studies and 3 high-quality studies. ③Meta-analysis showed that there was no statistical difference between two groups in detection rate of malnutrition, and detection rate of growth retardation (P>0.05). The detection rate of nutritional anemia, detection rate of zinc deficiency, and rate of underweight in left-behind children group all were significantly higher than those in non-left-behind children group, and all the differences were statistically different (OR=1.93, 1.64, 1.22; 95%CI: 1.20-3.11, 1.19-2.27, 1.03-1.44; P=0.006, 0.003, 0.200).

Current evidence shows that left-behind children still have more health problems than non-left-behind children in parts of China. The detection rates of nutritional anemia and zinc deficiency, and rate of underweight are higher than those of non-left-behind children. However, due to the limitation of quantity and quality of studies included in this research, and the heterogeneity among the studies, large-sample, multi-center and high-quality studies are still needed to conduct to fully grasp the health problems of left-behind children in China, and then providing better health care services for them.