Diagnostic efficacy of urine dipstick in detecting chronic kidney disease

Background: Proponents of routine urine dipstick screening to identify patients at risk for ESRD in the primary care setting have argued that urine dipsticks are inexpensive, low risk, acceptable to patients, and now, more accurate. Proponents believe that urine dipstick screening has the potential to improve outcomes for people with early disease and increase awareness of CKD. Most primary care physicians agree that populations who are at high risk for CKD should be tested and appropriately treated to decrease complications of ESRD. However, proponents of mass screening may not appreciate the challenges, limitations, and potential harms of screening. Urine dipstick testing does not meet all of the criteria for a good screening test. The aim of the study: To elucidate the diagnostic efficacy of the urine dipstick in detecting chronic kidney disease by assessing its validity as a screening test for detecting CKD. Materials and methods: A community-based cross-sectional study was conducted among 287 subjects aged 20 years and above residing in the P.K. Garden area of Chennai during November 2018 to January 2019. Subjects were interviewed with a questionnaire and blood samples were collected to estimate serum creatinine and a urine sample was collected to estimate the proteinuria using urine S. Thirumavalavan, Noormohamed, Balaji S.M., R Vijaya Kumar. Diagnostic efficacy of urine dipstick in detecting chronic kidney disease. IAIM, 2019; 6(3): 137-142. Page 138 dipstick. eGFR was calculated using CKD – EPI equation and CKD was diagnosed using KDOQI CKD guidelines. Results: The prevalence of Chronic Kidney Disease (<60 ml/min eGFR) in the study group was 10.45%. The Area under Curve (AUC) of the ROC curve for urine dipstick in detecting CKD was 0.948 (0.900 – 0.996) and the 2+ proteinuria was closest to the ideal test point. When proteinuria criteria set at dipstick 2+ or more, the sensitivity was 83.33% and specificity was 98.36%, positive predictive value was 83.33% and κ coefficient of agreement of proteinuria with CKD was 0.81. Conclusion: The urine dipstick test can be used as an effective screening tool in detecting CKD in primary care level. Non Communicable Diseases screening at primary health care level should include the screening of proteinuria using urine dipstick especially for people with risk factors like Diabetes and Hypertension.

Urinalysis: The Usefulness and Limitations of Urine Dipstick Testing

The urinalysis is an essential part of the diagnostic work-up for kidney disease and other renal system disorders. The dipstick test allows rapid and simultaneous chemical analyses of urine, including factors such as pH, specific gravity, protein, glucose, ketones, occult blood, bilirubin, urobilinogen, nitrite, and leukocyteesterase. The chemical reactions on dipstick are complicated and can be affected by oxidizing, reducing, and discoloring substances in the urine. Therefore, false positive and false negative results are common in dipstick testing. To obtain reliable results with the dipstick, it is necessary to collect urine cleanly and examine the urine carefully. It is mandatory to clearly understand the principles of dipstick testing to evaluate abnormal findings. If the urine dipstick results suggest hematuria, proteinuria, or urinary tract infection, microscopy of the urine should be performed to confirm the findings.

The Effect of Semen Contamination on the Urine Dipsticks / 임상검사와정도관리

BACKGROUND: The dipstick methodology is the most fundamental urinalysis but interfered by many factors. We evaluated the effect of semen contamination on the urine dipsticks. METHODS: Thirty-two specimens for semen analysis were enrolled. After semen was directly applied on urine dipsticks, residual samples were diluted in pooled normal urine. Urine dipsticks were performed at each dilution titer. Seminal plasma separated by centrifugation of semen were also tested in the same manner. RESULTS: All semen showed positive results for blood, protein and leukocytes. The intensities of reaction for blood and leukocytes were correlated with sperm concentration. The negative conversion of blood and protein occurred at 1:100, and that of leukocytes occurred at 1:50. Seminal plasma showed nearly the same findings. CONCLUSIONS: Semen contamination of urine may cause false positive reaction especially for blood and protein on the urine dipsticks. It should therefore be considered when assessing unexplained, transient hematuria or proteinuria.

Evaluation of the urine dipstick analysis for detection of bacteriuria.

This retrospective study was performed to evaluate the urine dipstick [ Leukocyte esterase and nitrite test ] for detection of bacteriuria and pyuria. Of the 1000 specimens, 296 [ 29.6% ] had positive culture results. The dipstick[ either leukocyte esterase or nitrite test ] test for detection of bacteriuria had a sensitivity of 85%, specificity of 51%, positive predictive value of 42% and negative predictive value of 89%, and the leukocyte esterase test for the detection of pyuria had a sensitivity of 96%, specificity of 73%, positive predictive value of 75% and negative predictive value of 95%. The sensitivity and negative predictive value of the dipstick test in the pediatric group was the lowest values when compared with the other groups. We conclude that, 1.) The dipstick test may be used as a screening test for pyuria. 2.) This test can not be used as a screening test for urinary tract infection [UTI ]. 3.) In contrast to sex, age affect the results of the urine dipstick test. 4.) This test has good result in adult particularly old age but, not in children.

Screening for Asymptomatic Bacteriuria in Korean Preschool Children / 대한비뇨기과학회지

PURPOSE: To determine the incidence of asymptomatic bacteriuria in Korean preschool children, we performed national survey. MATERIALS AND METHODS: We surveyed kindergardens in seven representative cities of Korea. Before performing urine culture, we selected children by urine dipstick screening method(leukocyte esterase and nitrite test). And we analysed the incidence according to sex, age and socioeconomic status. RESULTS: Total registered population was 2,239 children and male to female ratio was 1.16. Overall, asymptomatic bacteriuria was found in 1.03%(23 children). In the male the incidence was 0.3%(3 children) and in the female it was 2.0%(19 children). Less than 4 years old children showed higher incidence (2.9%) than those of any other age groups, such as, 0.5% in 4, 1.1% in 5 and 1.3% in 6 years old. High, middle and low socioeconomic status groups showed the incidence as 0%, 0.9% and 1.4%, respectively The number of leukocyte esterase positive children was 184(8.2%) and that of nitrite positive children was 115(5.1%). Among them urine culture was performed in 175children and 23 children showed significant bacteriuria(colony count> 100,000/ml), so predictability of asymptomatic bacteriuria by dipstick test was 13.1% Radiologic study was performed in 9 children who had bacteriuria, but none of them showed urological abnormalities. CONCLUSIONS: From the above data, we found that asymptomatic bacteriuria is more common in female, younger age and lower socioeconomic status among the Korean preschool children. Considering cost-benefit aspects of the screening for asymptomatic bacteriuria, however, we should re-evaluate the necessity of our study on these particular age groups.