The Need for Preoperative Laboratory Tests for Elective Surgery: A Systematic Review (Preprint)

BACKGROUND Preoperative laboratory testing is routinely performed before elective surgery to identify potential perioperative risks. However, growing evidence suggests that indiscriminate testing may offer limited clinical benefit while increasing healthcare costs OBJECTIVE This systematic review aimed to evaluate the clinical utility, necessity, and cost-effectiveness of preoperative laboratory tests in patients undergoing elective surgery METHODS This systematic review was conducted in accordance with the PRISMA 2020 guidelines. A comprehensive literature search was performed in PubMed, the Cochrane Library, and Google Scholar for studies published between January 2015 and December 2024. Eligible studies assessed the clinical relevance, utility, or cost-effectiveness of preoperative laboratory testing in elective surgical patients. Two reviewers independently screened studies, extracted data, and synthesized findings narratively. Methodological quality was assessed using the Newcastle–Ottawa Scale for observational studies. This review was not registered in PROSPERO RESULTS Thirty-two studies met the inclusion criteria, including reviews, cohort studies, cross-sectional studies, retrospective studies, and clinical audits. Most studies reported that routine laboratory tests such as complete blood count, renal and liver function tests, and coagulation profiles were unnecessary for low-risk patients undergoing elective surgery, with no significant impact on perioperative outcomes. Selective, indication-based testing guided by clinical assessment was found to be more effective and cost-efficient. In contrast, targeted testing remained beneficial for high-risk patients, elderly individuals, and those undergoing major or complex procedures. CONCLUSIONS Routine preoperative laboratory testing for all elective surgical patients is clinically inefficient and economically unjustified. A selective, patient-centered testing strategy based on clinical evaluation and surgical risk should be adopted to enhance patient safety and optimize healthcare resource utilization.