Table 2. Eligibility criteria.

Category	Inclusion criteria	Exclusion criteria
Population	Adult patients (≥18 y) undergoing surgery	―a
Predictive tool	ML-based models explicitly developed to predict intraoperative bleeding risk	Models predicting only postoperative bleeding or failing to distinguish intraoperative or postoperative outcomes
Outcome reporting	Reported at least one performance metric: area under the curve (AUC), sensitivity, or specificity	―
Study design	Primary research: retrospective or prospective cohort studies, case-control studies	Conference abstracts, reviews, case reports, editorials, letters
Publication status	Full text in Chinese or English (including peer-reviewed preprints)	Non–peer-reviewed manuscripts, publications not in Chinese or English
Data source	―	Nonclinical or invalid sources: animal experiments, simulated datasets, nonhospital data

^aNot applicable.