Comparative evaluation of biochemical and microscopic urinalysis in pediatric population

ABSTRACT

The authors determined the value of performing urine microscopy on biochemically negative urine sepcimens in a pediatric population. The 746 urine specimens of patients who were either visited or admitted to the Department of Pediatrics, National Police Hospital, from March 1991 to July 1992 were reviewed on the basis of comparative evaluation of biochemical and microscopic urine analysis. Eight reactions of Clinitek(r) 200 were used as biochemical indicators, namely, pH, nitrite, albumin, glucose, ketone, urobilinogen, bilirubin, and blood. Out of 746 urine specimens studied, 186 were true positive. Thirty-six specimens reacted biochemically in the absence of positive microscopic findings (false postive), 492 specimens were true negatives. Thirty-two specimens had negative biochemical indicators, in spite of positive microscopy. The sensitivity of the biochemical parameters for predicting significant microscopy of urinary sediment is 85% and the specificity is 99%. The positive predictive value is 69.7% and the negative predictive value is 99.3%. The sensitivity of blood for RBC is 94%. and the specificity is 99%. The predictive value of a positive result is 84.6% and that of a negative result is 99.7%. We therefore conclude that urine microscopy is less necessary in biochemically negative urine specimens from asymptomatic pediatric patients, with hopefully resultant time and cost effectiveness.