Urinalysis in Acute Care of Adults: Pitfalls in Testing and Interpreting Results

Abstract

Abstract Background.  Rapid urine tests for infection (urinalysis, dipstick) have low up-front costs. However, many false positives occur, with important downstream consequences, including unnecessary antibiotics. We studied indications, collection technique, and results of urinalyses in acute care. Methods.  This research was a prospective observational study of a convenience sample of emergency department (ED) patients who had urinalysis performed between June 1, 2012 and February 15, 2013 at an urban teaching hospital. Analyses were conducted via t tests, χ2 tests, and multivariable logistic regression. Results.  Of 195 cases included in the study, the median age was 56 and 70% of participants were female. There were specific symptoms or signs of urinary tract infection (UTI) in 74 cases (38%; 95% confidence interval [CI], 31%–45%), nonspecific symptoms or signs in 83 cases (43%; 95% CI, 36%–50%), and no symptoms or signs of UTI in 38 cases (19%; 95% CI, 14%–25%). The median age was 51 (specific symptoms), 58 (nonspecific symptoms), and 61 (no symptoms), respectively (P = .005). Of 137 patients who produced the specimen without assistance, 78 (57%; 95% CI, 48%–65%) received no instructions on urine collection. Correct midstream clean-catch technique was used in 8 of 137 cases (6%). Presence of symptoms or signs was not associated with a new antibiotic prescription, but positive urinalysis (OR, 4.9; 95% CI, 1.7–14) and positive urine culture (OR, 3.6; 95% CI, 1.1–12) were. Of 36 patients receiving antibiotics, 10 (28%; 95% CI, 13%–43%) had no symptoms or nonspecific symptoms. Conclusion.  In this sample at an urban teaching hospital ED, urine testing was not driven by symptoms. Improving practice may lower costs, improve efficiency of care, decrease unnecessary data that can distract providers and impair patient safety, decrease misdiagnosis, and decrease unnecessary antibiotics.