A Quantification of the Impact of Awaiting Results of a Urinalysis upon Emergency Department Length of Stay

BackgroundDespite the popular conception that ordering a urinalysis causes a significant increase in emergency department (ED) length of stay (LOS), there is little research on its actual impact.ObjectivesThis study investigated the quantitative impact of obtaining the results of a urinalysis, compared with the quantitative impact of obtaining the results of any laboratory testing of blood (“blood testing”), upon ED LOS in the National Hospital Ambulatory Medical Care Survey–Emergency Department (NHAMCS-ED) dataset.MethodsThe NHAMCS-ED dataset was queried from 2006–2015, comparing LOS in visits where urinalysis was ordered, blood testing was ordered, both were ordered, or neither.ResultsThere were 1,232,279,000 ED visits with LOS data found in the study period. Urinalysis was performed in 24.2% of visits, blood testing in 36.7%, both in 18.2%, and none in 57.4%. Median LOS was 153 min. No blood or urine testing had a median LOS of 109, urinalysis only 161 min, blood testing only 221 min, and both, 250 min.ConclusionUrinalysis does increase LOS, but blood testing increases it more, with additive effects when both are ordered.