Accuracy of Canadian CT Head Rule and New Orleans Criteria for Minor Head Trauma; a Systematic Review and Meta-Analysis

INTRODUCTION: The present meta-analysis has two objectives; primarily, the predictive values of Canadian computed tomography (CT) head rule (CCHR) and New Orleans Criteria (NOC) will be compared. Secondly, the possibility of interchangeable use of the two models in cases of contraindication will be evaluated. METHODS: An extensive search was performed in Medline, Embase, Scopus and Web of Science electronic databases from the inception of databases until the end of July 2020. All prospective and retrospective observational and diagnostic accuracy studies comparing NOC and CCHR on a single group of patients were included. Data were entered to STATA 14.0 statistical program, and analyses were performed using “metandi” command. RESULTS: Data from 14 articles were included (21140 samples). Summary sensitivity, specificity, and diagnostic odds ratio of CCHR in prediction of positive CT findings were 89.8% (95% CI: 79.6 to 95.2), 38.3% (95% CI: 34.0 to 42.8), and 5.5 (95% CI: 2.3 to 13.1), respectively. In addition, summary sensitivity, specificity, and diagnostic odds ratio of NOC in prediction of positive CT findings were 97.2% (95% CI: 89.7 to 99.2), 12.3% (95% CI: 7.4 to 19.8), and 4.8 (95% CI: 1.2 to 18.3), respectively. Summary sensitivity, specificity, and diagnostic odds ratio of CCHR in prediction of clinically important TBI (ciTBI) in mild TBI patients were 92.5% (95% CI: 79.5 to 97.5), 40.1% (95% CI: 34.8 to 45.6), and 8.3 (95% CI: 2.4 to 29.2), respectively. In addition, summary sensitivity, specificity, and diagnostic odds ratio of NOC in prediction of ciTBI were 98.3% (95% CI: 93.8 to 99.6), 8.5% (95% CI: 4.8 to 14.5), and 5.4 (95% CI: 1.5 to 20.0), respectively. CONCLUSION: The present meta-analysis demonstrated that both CCHR and NOC scores have a good predictive value in predicting the presence of abnormal findings in CT scan and ciTBI. The similar performance of CCHR and NOC models results in their interchangeable use in cases of contraindication.