A number of additional limitations of this study are worth noting. Firstly, the meta-analysis was based on data drawn from only five countries which may affect the generalizability of some of the findings to other eligible LMICs. Secondly, potentially important risk factors were excluded because of lack of (insufficient or reliable) data. However, the absence of evidence is not necessarily evidence of absence of the significance of the excluded risk factors [48]. Thirdly, we broadened the definition of severe hyperbilirubinemia to include all severity types: mild, moderate, severe, extreme hyperbilirubinemia as well as acute and chronic bilirubin encephalopathy. However, risk factors may vary for various levels of severity of hyperbilirubinemia, ABE and kernicterus [8]. Fourthly, we were unable to determine regional differences in risk factors even among the three regions (South Asia, Sub-Saharan Africa and Middle-East/North Africa) covered in this study. Fifthly, the diagnostic criteria for the reported risk factors were not uniform across all studies. Lastly, the sources of heterogeneity could not be identified by methods such as meta-regression or subgroup analysis due to fewer number of studies. Notwithstanding, the clinical risk factors reported in this study are consistent with findings in several studies that have investigated the causes of severe neonatal hyperbilirubinemia in LMICs and thus warrant attention.