Quantitative G6PD point-of-care test can be used reliably on cord blood to identify male and female newborns at increased risk of neonatal hyperbilirubinaemia: a mixed method study

IntroductionNew point-of-care (POC) quantitative G6PD testing devices developed to provide safe radical cure for P. vivax malaria may be used to diagnose G6PD deficiency in newborns at risk of severe neonatal hyperbilirubinaemia, improving clinical care, and preventing related morbidity and mortality. Methods: We conducted a mixed-methods study analyzing technical performance and usability of the "STANDARD G6PD" Biosensor when used by trained midwives on cord blood samples at two rural clinics on the Thailand-Myanmar border. ResultsIn 307 cord blood samples, the Biosensor had a sensitivity of 1.000 (95%CI 0.859-1.000) and a specificity of 0.993 (95% CI 0.971-0.999) as compared to gold standard spectrophotometry to diagnose G6PD deficient newborns using a receiving operator characteristic (ROC) analysis-derived threshold of [≤]4.8IU/gHb. The Biosensor had a sensitivity of 0.727 (95%CI: 0.498-0.893) and specificity of 0.933 (95%CI: 0.876-0.969) for 30-70% activity range in females using ROC analysis-derived range of 4.9 to 9.9IU/gHb. These thresholds allowed identification of all G6PD deficient neonates and 80% of female neonates with intermediate phenotypes. Need of phototherapy treatment for neonatal hyperbilirubinaemia was higher in neonates with deficient and intermediate phenotypes as diagnosed by either reference spectrophotometry or Biosensor. Focus group discussions found high levels of learnability, willingness, satisfaction, and suitability for the Biosensor in this setting. The staff valued the capacity of the Biosensor to identify newborns with G6PD deficiency early ("We can know that early, we can counsel the parents about the chances of their children getting jaundice") and at the POC, including in more rural settings ("Because we can know the right result of the G6PD deficiency in a short time. Especially for the clinic which does not have a lab"). Conclusions: The Biosensor is a suitable tool in this resource-constrained setting to identify newborns with abnormal G6PD phenotypes at increased risk of neonatal hyperbilirubinaemia.