comparison of urine culture and urine dipstick analysis in diagnosis of urinary tract infection

urine dipstick is a useful and commonly used test because of its rapidity and low cost; however its diagnostic accuracy is debatable. this research were carried out to determine sensitivity, specificity and positive and negative predictive values of nitrite (nit) and leukocyte esterase (le) testing in relation to urine culture. this research was conducted on 100 hospitalized patients with clinical signs and symptoms compatible with urinary tract infections (uti). urine culture and dipstick tests were carried out on urine samples of all patients. urinalysis le and nit studies were performed in fresh and uncentrifuged urine by using a manual urine analyzer (rapignost, co. marburg, germany). the urine culture was considered as gold standard. urine cultures were positive in 75 (75%) patients. dipstick tests of urine were positive in 79(79%) patients. sensitivity, specificity, positive predictive value (ppv) and negative predictive value (npv) of dipstick test were 76%, 12%, 72% and 14% respectively. although dipstick test of le and nit can avoid a large part of the cost incurred by urine culture, any method of urine screen (le and nit) shouldn't be substituted for a urine culture in the symptomatic patients in childhood.