Evaluating CASS and BATSS scores for predicting laparotomy in blunt abdominal trauma: meta-analysis from low- and...

Early identification of intra-abdominal injury (IAI) following blunt abdominal trauma (BAT) is critical to reducing mortality in low- and middle-income countries (LMICs) where access to contrast-enhanced computed tomography (CECT) is limited. The Clinical Abdominal Scoring System (CASS) and the Blunt Abdominal Trauma Scoring System (BATSS) are used to guide triage and operative decision-making; however, their diagnostic accuracy in LMICs remains uncertain and inconsistently reported. The objective of this study was to evaluate the pooled diagnostic accuracy of CASS and BATSS in predicting the need for laparotomy or the presence of IAI in adult BAT patients in LMICs.

We conducted a systematic review and meta-analysis in accordance with PRISMA 2020 guidelines. PubMed, Web of Science, Scopus, and Lens.org were searched from January 2009 to January 2025. Eligible studies evaluated adult patients with BAT in LMICs and reported diagnostic accuracy of CASS or BATSS for predicting IAI or need for laparotomy using CECT, laparotomy, or composite reference standards. Random-effects meta-analyses were used to pool sensitivity, specificity, and diagnostic odds ratios (DORs). Heterogeneity and publication bias were formally assessed.

Twelve studies encompassing 2,148 patients met inclusion criteria, including 7 BATSS studies and 5 CASS studies. For BATSS, pooled sensitivity was 57.9% and specificity 86.5%, with a pooled DOR of 70.1 (95% CI: 9.38-520.61). For CASS, pooled sensitivity was 77.2%, specificity was 90.6%, and pooled DOR was 50.4 (95% CI: 6.59-384.91). Substantial heterogeneity was observed for both systems (I²=88.5% for BATSS; I²=74.6% for CASS). BATSS showed better pooled performance at a cut-off ≥ 12; however, variation in thresholds across studies limited direct comparability of pooled estimates. Publication bias was detected for BATSS but not for CASS, indicating that BATSS estimates may be vulnerable to small-study effects or selective publication.

Based on a limited evidence base, both CASS and BATSS appear to have diagnostic value for identifying IAI in adult BAT patients in LMICs, although neither should be used as a standalone decision tool. CASS may be more useful for initial rule-out triage where imaging is unavailable, whereas BATSS may support rule-in decisions for definitive imaging or surgical intervention; however, these interpretations should be made cautiously because of high heterogeneity, small study numbers, variable thresholds, and publication bias affecting BATSS. Local validation, threshold optimization, and prospective multicenter evaluation are essential before routine implementation. When cautiously integrated into structured trauma protocols, these scoring systems may support triage and imaging prioritization in resource-constrained settings, but current pooled estimates should be interpreted as preliminary.