Objectives: Physical examination, ultrasonography, and laboratory tests fail to reliably establish the preoperative diagnosis of tubal rupture in patients with ectopic pregnancy (EP), leading to a high rate of diagnostic laparoscopy. The aim of this study was to construct and to evaluate a clinical prediction rule for tubal rupture screening based on a self-assessment questionnaire, among patients with EP.
Methods: A standardized questionnaire was constructed via semistructured interviews of patients with acute pelvic pain. Features associated with tubal rupture were then identified in 141 prospectively included patients with tubal pregnancy, including 30 with tubal rupture, in five hospitals. Multiple logistic regression was used to select the best combination of independent features for predicting tubal rupture. Cross-validation was with the jackknife method. The main outcome measure was diagnostic accuracy of the questionnaire for ruling out tubal rupture.
Results: Eighty-nine items characterizing acute pelvic pain were identified. Among them, four contributed independently to the diagnosis of tubal rupture: vomiting during pain, diffuse abdominal pain, acute pain for longer than 30 minutes, and flashing pain. The presence of one or more of these features had 93% sensitivity (95% confidence interval [CI] = 84% to 100%) and 44% specificity (95% CI = 35% to 53%) for tubal rupture, with a negative likelihood ratio for ruling out tubal rupture of 0.16.
Conclusions: These results suggest that a standardized questionnaire may contribute to ruling out tubal rupture in patients with EP.
© 2012 by the Society for Academic Emergency Medicine.