Prospective Validation of Clinical Score for Males Presenting With an Acute Scrotum

Abstract

Objective: The objective was to validate the Testicular Workup for Ischemia and Suspected Torsion (TWIST) score among pediatric emergency medicine providers for the evaluation of pediatric males presenting with testicular pain and swelling (acute scrotum). Methods: We conducted a prospective cohort study of males 3 months to 18 years old presenting with an acute scrotum. History and physical examination findings, including components of the TWIST score (hard testicle, absent cremasteric reflex, nausea/vomiting, and high riding testicle) as well as diagnostic results (ultrasound, urine, sexually transmitted infection testing) were recorded. Testicular torsion was confirmed by surgical exploration. Frequencies of patient characteristics, TWIST components, and tests were calculated. We performed the kappa statistic for inter-rater reliability and calculated the test characteristics and receiver operator characteristics curves for the TWIST score (range = 0–7). Results: During the study period 258 males were enrolled in the study; 19 (7.4%) had testicular torsion. The mean (±SD) age was 9.8 (±0.3) years. The high-risk TWIST score of 7 had 100% specificity (95% confidence interval [CI] = 98%–100%) with 100% positive predictive value (95% CI = 40%–100%) for testicular torsion. The area under the curve was 0.82. The kappa statistic for the overall TWIST score was fair at 0.39. Conclusions: In this prospective validation of the TWIST score among pediatric emergency providers, the high-risk score demonstrated strong test characteristics for testicular torsion. The TWIST score could be used as part of a standardized approach for evaluation of the pediatric acute scrotum to provide more efficient and effective care.