Utility of screening urinalysis to detect abdominal injuries in suspected victims of child physical abuse

Background: Urinalysis, liver enzymes (LE) and lipase are used to screen for abdominal injuries in children with suspected physical abuse (SPA). However, data on the utility of urinalysis is limited. Objectives: Describe the prevalence of hematuria in evaluations for SPA. Determine test characteristics of hematuria, LE and lipase to identify kidney and other abdominal injuries among children with SPA. Participants and setting: Children < 7 years receiving a urinalysis during evaluation for SPA by a hospital child protection team. Methods: Demographic, clinical, and laboratory data including presence of hematuria (blood on urine dipstick), elevated LE (> 80 U/L) and elevated lipase (> 100 U/L) were abstracted retrospectively. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for the overall study population and for patients without abdominal symptoms. Results: Ten percent of patients had hematuria (N = 237). Prevalence of abdominal and kidney injuries was 7 % and 1 % respectively. Of 3 patients with kidney injury, 2 had hematuria and all had elevated LE. Sensitivity (67 %) and NPV (99 %) of hematuria to detect kidney injuries were lower than LE and the same as lipase. Specificity (91 %) and PPV (8%) of hematuria to detect kidney injury were greater than LE and similar to lipase. Sensitivity of hematuria to detect any abdominal injury (50 %) was lower than LE (81 %). Sensitivity of hematuria to detect occult abdominal injury was 0 %. Conclusions: Hematuria alone did not lead to detection of kidney injury. Test characteristics of hematuria were largely similar or inferior to LE and lipase.