Which Urine Sampling Method is Suitable for Women Visiting the Emergency Department?

ABSTRACT

BACKGROUND: Urinalysis is a useful laboratory test in the diagnosis of various diseases. In sampling for the urinalysis, there is much concern about contamination that can lead to misdiagnosis in the mid-stream urine sampling method. We conducted this study to determine, in terms of concordance of results and contamination in culture, whether there was any superiority in mid-stream sampling methods with or without disinfection measures compared to the catheterization method. MATERIALS AND EMTHODS We used three kinds of urine sampling methods sequentially, mid-stream non-clean catch, mid-stream clean catch, and catheterization, for ambulatory, non-pregnant, non-menstruating female patients who visited NHIC Ilsan Hospital emergency department during a one-week period in September 2001. Each sample was electrophotometrically analyzed for leukocyte esterase, nitrite, and blood by using a reagent strip and was cultured immediately or after overnight refrigeration. RESULTS: Of the 41 patients, 9 had culture-proven urinary tract infections. The concordance rates(kappa) for nitrite, blood, and leukocyte esterase were 0.875, 0.403, and 0.406 between non-clean catch and catheterized samples and 0.875, 0.481, and 0.560 between clean catch and catheterized samples, respectively. The contamination rate of the non-clean catch, the clean catch, and the catheterized samples were statistically different 51.2%, 29.3% and 0%, respectively. CONCLUSION: We found that cleaning with disinfectant was effective for reducing the contamination rate, even though the best urine sampling method for zero contamination was catheterization. We recommend considering cost, patients' comfort, an acceptable threshold for contamination, and the necessity for a culture before choosing a urine sampling method for women who visit the emergency department.