ACCURACY OF URINE DIPSTICK TO PREDICT URINARY TRACT INFECTIONS IN AN EMERGENCY DEPARTMENT
Abstract
Background: Urine dipstick is a useful and commonly used test in the Emergency Department because of its rapidity and low cost; however its diagnostic accuracy is debatable. Our objective was to compare the urine dipstick and urinalysis for Urinary Tract Infection in a developing country, where there are significant cost considerations. Methods: This was an observational study of adults’ patients presenting to Section of Emergency section (SEM) of the Aga Khan University Hospital, from March to May 1998. The patient’s urine sample was tested immediately, using the Multistix 10SG. The sample was sent within one hour to the hospital laboratory for analysis, while the urinary specimen was sent for culture, where appropriate. The dipstick results were compared with the results of automated urinalysis in the laboratory, leukocyte counts on microscopy and urine culture. Sensitivity, Specificity, and predictive values were also calculated. Results: We evaluated 984 samples of urine during the study period. The sensitivity of nitrite test was 81% and that of leukocyte esterase 77% for positive cultures. However, the sensitivity for combined nitrite and leukocyte esterase test was 94%. Nitrite test was more specific (87%) than leukocyte esterase test (54%) or both tests taken together (50%). The predictive value of nitrite and leukocyte esterase together for a negative urine culture was 95%. Leukocyte esterase test sensitivity increased as the number of white blood cells on microscopy increased. Similarly the predictive value of leukocytes on microscopy for a positive culture increased as the number of leukocytes increased. Conclusion: Dipstick alone cannot accurately predict urinary tract infection in emergency department.Key Words: urine dipstick, urinary tract infection, and emergency departmentReferences
Hurlbut TA, Littenburg B. The diagnostic accuracy of rapid dipstick tests to predict urinary tract infections. Am J Clin Pathol 1991; 96:582-6.
Bonnarddeaux A, Sommerville P, Kaye M. A study on the reliability of dipstick urinalysis. Clin Nephrol 1994; 41:167-72.
Propp DA, Weber D, Ciesla ML. Reliability of a urine dipstick in emergency department patients. Ann Emerg Med 1989; 18 (5): 560-3.
Press SM, Smith AD. Incidence of negative hematuria in patients with acute urinary lithiasis presenting to the emergency room with flank pain. Urology 1995; 45(5): 753-7.
Ohly N, Teece S. Accuracy of negative dipstick urine analysis in ruling out urinary tract infection in adults. Emerg Med J 2003; 20 (4): 362-3
Zainal D, Baba A. The value of positive nitrites in screening asymptomatic bacteriuria amongst Malaysian school children. Southeast Asian J Trop Med Public Health 1996; 27 (1): 184-8.
Ames Multireagent Strip. Bayer Diagnostics, Division of Bayer Australia Limited.
Christenson RH, Tucker JA, Allen E. Results of dipstick tests, visual inspection, microscopic examination of urine sediment, and microbiological cultures of urine compared for simplifying urinalysis. Clin Chem 1985; 31: 448-50.
Mariani AJ, Luangphinith, S, Loo S, Scottolini A, Hodges CV. Dipstick chemical urinalysis: an accurate cost-effective screening test. J Urol 1984; 132: 64-6.
Wigton RS, Hoellerich VL, Ornato JP, Leu V, Mazzotta LA, Cheng IH. Use of clinical findings in the diagnosis of urinary tract infection in women. Arch Intern Med 1985; 145: 2222-7.
Wiggelinkhuizen J, Maytham D, Hanslo DH. Dipstick screening for urinary tract infection. S Afr Med J. 1988; 74: 224-8.
Fowlis GA, Waters J, Williams G. The cost effectiveness of combined tests (Multistix) in screening for urinary tract infections. J R Soc Med.1994; 87: 681-2.
Shaw ST, Poon SY, Wong ET. “Routine urinalysis.” Is the dipstick enough? JAMA. 1985; 253: 1596-1600.
Carroll KC, Hale DC, VonBoerum DH. Laboratory evaluation of urinary tract infections in an ambulatory clinic. Am J Clin Pathol 1994;101:100-3.
Semeniuk H, Church D. Evaluation of the leukocyte esterase and nitrite urine dipstick screening tests for detection of bacteriuria in women with suspected uncomplicated urinary tract infections. J Clin Microbiol 1999; 37: 3051-2.
Nostrand JD, Junkins AD, Bartholdi RK. Poor predictive ability of urinalysis and microscopic examination to detect urinary tract infection. Am J Clin Pathol 2000; 113: 709-13.
Lammers RL, Gibson S, Kovacs D, Sears W, Strachan G. Comparison of test characteristics of urine dipstick and urinalysis at various test cutoff points. Ann Emerg Med 2001;38:505-12.
Wenk RE, Dutta D, Rudert J, Kim Y, Steinhagen C. Sediment microscopy, nitriuria, and leukocyte esteriuria as predictors of significant bacteriuria. J Clin Lab Automation 1982;2:117-21.
Sewell DL, Burt SP, Gabbert NJ, Bumgardner RV. Evaluation of the Chemstrip 9TM as a screening test for urinalysis and urine culture in men. Am J Clin Pathol 1985; 83:740-3.
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