Comparing Urine Analysis and Urine Dipstick Tests Used in the Diagnosis of Renal Injury in Children With Blunt Abdominal Trauma in Shiraz, Iran

Abstract

Background: Blunt abdominal trauma (BAT) is the most common cause of abdominal injury and is responsible for renal injury in children. Urine dipstick is used in various clinical conditions, and its use in the diagnosis of microscopic hematuria is very common in adults, but its efficacy in children with BAT is unclear. Objective: To determine the accuracy of urine dipstick test and compare it with microscopic urine analysis (UA) in predicting urinary system injury. Methods: This prospective cross-sectional study was conducted on children with BAT who were referred to the Acute Care II of the Emergency Medicine Department of Shiraz Namazi Hospital in south of Iran (April-October 2018). The results of the urine dipstick test were compared with the results of UA, abdominal computed tomography (CT) scan as the gold standard, and the point-of-care ultrasound (POCUS). The diagnostic tests (sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, and accuracy) were calculated. Results: A total of 380 patients were enrolled, with a mean ± standard deviation age of 6.3 ± 3.45 years. We obtained a sensitivity, specificity, and accuracy of 71.43% (95% CI, 41.90-91.61), 96.99% (95% CI, 94.69-98.49), and 96.05% (95% CI, 93.57-97.77), respectively, with a negative predictive value (NPV) of 98.89% (95% CI, 97.48-99.51) for the dipstick test in comparison with UA. In comparing the results of the dipstick and UA tests with CT scan, no difference was found in terms of sensitivity (P = 0.35), specificity (P = 0.65), accuracy (P = 0.72), and area under the curve (P = 0.97). Conclusion: Due to no difference in diagnostic values between the urine dipstick and UA tests, dipstick can be considered as an alternative means of UA in the management algorithm of pediatric BAT. Also, with higher specificity and NPV of the dipstick test in comparison with the UA test, based on the negative results of dipstick, hematuria can be ruled out in children with BAT.