title: Prospective pilot derivation of a decision tool for children at low risk for testicular torsion.
abstract: OBJECTIVE
  The purpose of this study was to derive a pilot clinical decision tool with 100% negative predictive value for testicular torsion based on prospectively collected data in children with acute scrotal pain.
  
  
  METHODS
  This was a prospective cohort study of a convenience sample of newborn to 21-year-old males evaluated for acute (72 hours or less) scrotal pain at an urban children's hospital emergency department (ED). A pediatric emergency medicine fellow or attending physician documented history and examination findings on a standardized data collection form. The study investigators used ultrasound (US), operative reports, or clinical follow-up to identify patients who had testicular torsion. Pearson's chi-square test and odds ratios (OR) were used to identify factors associated with the diagnosis of testicular torsion. The authors also used a recursive partitioning model to create a low-risk decision tool for testicular torsion.
  
  
  RESULTS
  Of the 450 eligible patients, 228 (51%) were enrolled, with a mean (± SD) age of 9.9 (± 4.1) years, including 21 (9.2%, 95% confidence interval [CI] = 5.8% to 13.7%) with testicular torsion. The derived clinical decision tool consisted of three variables: horizontal or inguinal testicular lie (OR = 18.17, 95% CI = 6.2 to 53.2), nausea or vomiting (OR = 5.63, 95% CI = 2.08 to 15.22), and age 11 to 21 years (OR = 3.9, 95% CI = 1.27 to 11.97). These variables had a sensitivity of 100% (95% CI = 98% to 100%) and negative predictive value of 100% (95% CI = 98% to 100%) for the diagnosis of testicular torsion.
  
  
  CONCLUSIONS
  Based on a decision tool derived with recursive partitioning, study patients with all of the following characteristics had no risk of testicular torsion: normal testicular lie, lack of nausea or vomiting, and age 0 to 10 years. Future research should focus on externally validating this tool to optimize emergent evaluation when testicular torsion is likely, while minimizing routine sonographic evaluation when patients are unlikely to have a serious condition requiring immediate management.
authors.affiliation: Department of Pediatrics, Section of Emergency Medicine, Baylor College of Medicine, Houston, TX, USA. mxshah@texaschildrens.org
authors.forename: Manish I
authors.initials: MI
authors.lastname: Shah
authors.forename: A
authors.initials: A
authors.lastname: Chantal Caviness
authors.forename: Donna R
authors.initials: DR
authors.lastname: Mendez
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003661:Decision Support Techniques; D004632:Emergency Medical Services / Q000379:methods*; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010146:Pain / Q000175:diagnosis*; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013086:Spermatic Cord Torsion / Q000175:diagnosis*; D055815:Young Adult