Clinical value of urinary dipstick test in acute emergency department

Urinary tract infections are a common cause of referral to the emergency department. In the January issue of DMJ, Chernaya and colleagues report results of a quality control study including 500 patients who had performed urine culture while admitted to the Internal Medicine Emergency Department at Herlev Hospital. Positive culture of bacteria in the urine was compared with the results of a urinary dipstick test for leukocyte esterase (an indicator of the presence of leucocytes) and for the nitrite (indicator of the presence of nitrate-reducing bacteria). The authors report sensitivity and specificity of these two tests and positive predictive value and negative predictive of each test and of the combination of both tests. The study concluded that in women, prediction of urinary tract infection based on the results of the dipstick test is unreliable. In men, the combination of a negative leukocyte esterase and a negative nitrite, can rule out significant bacteriuria with 93% certainty.