To explore the application value of automated image-based bilirubin (AIB) detection by smartphone application in neonates with jaundice.

From January to December, 2018, a total of 300 neonates with jaundice were selected into this study. Venous blood was collected from all children to determine serum total bilirubin (TSB) concentration, transcutaneous jaundice tester was used to determine the transcutaneous bilirubin (TcB) concentration, and smartphone application program was used to automatically take pictures to detect the AIB concentration. Paired t test was used to compare the concentrations of AIB and TSB, TcB and TSB in neonates with jaundice. The Bland-Altman consistency test was used to analyze the consistency between different methods, and then the linear correlation analysis was used to analyze the correlation between two detection methods. The procedures followed in this study were in accordance with the standards established by the Committee of Investigation in Human Beings of Tangshan Maternal and Children Health Hospital, and this study was approved by the committee (Approval No. 202002901). Informed consent was obtained from each participates′ guardians.

①The concentrations of TSB, TcB and AIB of 300 children were (192.2±66.5) μmol/L, (195.3± 70.2) μmol/L and (198.7±52.6) μmol/L, respectively. There were no significant differences between the concentrations of AIB and TSB, TcB and TSB, respectively (t=1.333, 0.564, P=0.182, 0.586). The Bland-Altman consistency test results showed that AIB and TSB, TcB and TSB had strong consistency [96.0% (288/300), 97.0% (291/300)]. Linear correlation analysis between AIB and TSB, TcB and TSB showed positive correlation, respectively (r=0.601, 0.783, P=0.024, 0.018). ② There were no statistically significant differences between AIB and TSB, between TcB and TSB of children with gestational age>35 weeks (t=0.041, 0.188, P=0.974, 0.867); there was no significant difference between TcB and TSB in children with gestational age<35 weeks (t=1.385, P=0.175), but there was significant difference between AIB and TSB (t=2.931, P=0.002). There were strong consistency between AIB and TSB, TcB and TSB in neonates with jaundice at different gestational age and different age. ③ Receiver operating characteristics (ROC) curve analysis showed the following. The area under curve (AUC) of AIB and TcB for serum bilirubin levels were 0.693 (95%CI: 0.614-0.723, P=0.014) and 0.690 (95%CI: 0.604-0.776, P=0.027), respectively. According to the principle of maximum Youden index, the optimal critical value of serum bilirubin level determined by AIB was 193.247 μmol/L, and the sensitivity and specificity was 68.7% and 67.4%, respectively. The optimal critical value for the determination of serum bilirubin by TcB was 189.348 μmol/L, and the sensitivity was 75.0% and the specificity was 71.2%.

Both AIB and TcB have good consistency with TSB, and have high sensitivity and specificity. Smartphone applications are more suitable for children with jaundice who need follow-up after discharge.