Nine studies were included in the review (12,631 participants): six retrospective; and three prospective case series.
The positive predictive value of coagulation tests ranged from 0.03 (95% CI: 0.00 to 0.15) to 0.22 (95% CI: 0.09 to 0.43). The positive predictive value of bleeding history was reported by four studies and ranged from 0.02 (95% CI: 0.01 to 0.03) to 0.23 (95% CI: 0.06 to 0.54).
The likelihood ratio of coagulation tests ranged from 0.94 (95% CI: 0.56 to 1.57) to 5.10 (95% CI: 1.18 to 21.96). The likelihood ratio of bleeding history was reported by four studies and ranged from 1.27 (95% CI: 0.99 to 1.64) to 5.04 (95% CI: 3.48 to 7.31).
The difference in bleeding rates between patients with abnormal and normal coagulation tests ranged from -0.008 (95% CI: -0.070 to 0.069) to 0.166 (95% CI: 0.037 to 0.372).