title: Emergency physician ultrasonography for evaluating patients at risk for ectopic pregnancy: a meta-analysis.
abstract: OBJECTIVE
  Ectopic pregnancy is a common concern in emergency departments (EDs) and remains the leading cause of first-trimester mortality. Pelvic ultrasonography by emergency physicians has been investigated as a diagnostic test for ectopic pregnancy. We present a meta-analysis of the use of emergency physician ultrasonography in the evaluation of patients at risk of ectopic pregnancy.
  
  
  METHODS
  A structured search was performed of both MEDLINE and EMBASE. Inclusion criteria were that (1) the study reported original research on ED patients at risk for ectopic pregnancy; (2) an emergency physician performed and interpreted the initial pelvic ultrasonography; and (3) follow-up was conducted on all patients. Sensitivity was defined as the proportion of patients with ectopic pregnancy for which ED ultrasonography demonstrated no intrauterine pregnancy. A random-effects model was used to obtain summary test characteristics.
  
  
  RESULTS
  The initial search showed 576 publications, abstract review yielded 60 with potential relevance, and 10 studies were included. There was a total of 2,057 patients, of whom 152 (7.5%) had ectopic pregnancy. The pooled sensitivity estimate was 99.3% (95% confidence interval [CI] 96.6% to 100%), negative predictive value was 99.96% (95% CI 99.6% to 100%), and negative likelihood ratio was 0.08 (95% CI 0.025 to 0.25), all without significant heterogeneity.
  
  
  CONCLUSIONS
  The results of this meta-analysis suggest that in a wide variety of clinical settings, the use of bedside ultrasonography performed by emergency physicians as a diagnostic test for ectopic pregnancy provides excellent sensitivity and negative predictive value. Visualization of an intrauterine pregnancy by an emergency physician is generally sufficient to rule out ectopic pregnancy.
authors.affiliation: Department of Emergency Medicine, University of California, San Francisco, CA 94143, USA. jstein@medicine.ucsf.edu
authors.forename: John C
authors.initials: JC
authors.lastname: Stein
authors.forename: Ralph
authors.initials: R
authors.lastname: Wang
authors.forename: Naomi
authors.initials: N
authors.lastname: Adler
authors.forename: John
authors.initials: J
authors.lastname: Boscardin
authors.forename: Vanessa L
authors.initials: VL
authors.lastname: Jacoby
authors.forename: Gloria
authors.initials: G
authors.lastname: Won
authors.forename: Ruth
authors.initials: R
authors.lastname: Goldstein
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kohn
mesh_terms: D016001:Confidence Intervals; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D019095:Point-of-Care Systems / Q000592:standards / Q000706:statistics & numerical data; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014463:Ultrasonography