Characteristics of included studies.

Background
Newborn screening for biliary atresia (BA) may facilitate earlier diagnosis and intervention for improved clinical outcomes.
Methods
We systematically reviewed the accuracy of population-based screening strategies for BA in the newborn using PRISMA-DTA guidelines. We included cohort or cross-sectional studies. The screening (index) tests included stool color card (SCC) and direct/conjugated bilirubin (DB/CB) and the reference standard was intraoperative cholangiogram. Meta-analysis was performed using random-effects logistic regression models.
Results
We included 15 studies (1,816,722 participants) that assessed 5 different population-based screening strategies. QUADAS-2 assessment revealed high risk of bias for patient selection in one study and uncertain risks for reference standard in multiple studies. High certainty evidence suggests that DB/CB assessed after birth had a summary sensitivity of 100% (95% CI 100,100) and specificity of 98.8% (98.8,98.9) (5 studies, 662141 participants). Moderate certainty evidence suggests that SCC screening at a month of age had summary sensitivity of 79.6% (95% CI 70.6, 86.4) and specificity of 99.9% (95% CI 99.9, 99.9) (7 studies, 996262 participants).
Conclusions
DB/CB in the first few days of life has the best diagnostic accuracy for population screening for biliary atresia in the newborn. Future research should focus on cost-effectiveness and combinations of screening strategies.