206 www.blackwellpublishing.com/journals/afm ORIGINAL ARTICLE Asia Pacific Family Medicine 2003; 2: 206–212 Blackwell Science, LtdOxford, UKAFMAsia Pacific Family Medicine1444-1683© 2003 Blackwell Publishing Asia Pty LtdDecember 200324206212Original ArticleAccuracy of urinalysis in detection of UTIS Othman et al. Correspondence: Dr Sajaratulnisah Othman, Department of General Practice, Monash University, 867 Center Road, Victoria 3165, Australia. Email: sajaratulnisah.othman@med.monash.edu.au Accepted for publication 25 June 2003. OR I G I NAL ART I CLE Accuracy of urinalysis in detection of urinary tract infection in a primary care setting Sajaratulnisah OTHMAN, 1 Yook Chin CHIA 2 and Chirk Jenn NG 2 1 Department of General Practice, Monash University, Victoria, Australia and 2 Department of Primary Care Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia Abstract Aim: To determine the accuracy of urinalysis in the detection of urinary tract infection (UTI) in symp- tomatic patients at primary care level. Methods: A cross sectional study was undertaken on 100 patients with symptoms of UTI presenting at the Primary Care Clinic of University Malaya Medical Center, Kuala Lumpur, Malaysia during the months of August to November 1999. Their urine samples were tested simultaneously using urine dip- stick, urine microscopy and urine culture. Urine culture was used as the gold standard and UTI was diagnosed when the urine culture showed a bacteria count of ≥10 5 organisms per mL. The sensitivity and specificity of each test was calculated. Results: The prevalence of UTI was 25% in symptomatic patients. The urine dipstick for leukocyte esterase, nitrite and red blood cell had sensitivities of 76, 56 and 76%, respectively. Their specificities were 60, 81 and 61%, respectively. Urine microscopy for leukocytes, red blood cells and bacterial count had sensitivities of 80, 52 and 84%, while their specificities were 76, 80 and 54%, respectively. Conclusion: The prevalence of UTI in the present study was low despite reported symptoms of UTI. Urinalysis is needed to support the diagnosis of UTI. In the present study, while there is accuracy in the urinalysis (as the sensitivities and specificities of various tests are comparable with other studies); lack of precision in each test because of the wide range of 95% confidence interval make it less reliable. Cau- tion should be made in interpreting each test. „ 2003 Blackwell Publishing Asia and Wonca Key words: primary care, urinalysis, urinary tract infection. Introduction Urinary tract infections (UTI) are a common condition seen in clinical practice. In a few local studies, UTIs are as frequent as 4% of all consultations. 1–3 Microbiolog- ically, a UTI exists when pathogenic microorganisms are detected in the urine, urethra, bladder, kidney, or prostate. According to standard teaching, growth of more than 10 5 organisms per mL from a properly col- lected midstream ‘clean catch’ urine sample indicates infection. In the study by Kass it was found that 95% of women with acute pyelonephritis have a urine cul- ture of ≥10 5 bacteria per mL. 4 He also found that repeated urine cultures in asymptomatic patients with counts ≥10 5 bacteria per mL produced similar counts, whereas with urine counts less than 10 5 bacteria per mL, repeat counts produced different results at differ- ent times. On this basis, urine culture of 10 5 per mL or more has been taken as significant bacteriuria. 4 Urine culture has been the gold standard for diag- nosing UTI. However, there are problems with this: • waiting for laboratory results might delay the diagnosis • the test is expensive • not all practicing physicians, especially in small health clinics and general practice clinics are able to use this facility. For women who have symptoms of UTI and char- acteristic urine analysis findings it might be more prac- tical and cost effective to manage acute uncomplicated cystitis without an initial urine culture. Carlson and Mulley made a decision analysis model to estimate the