The Sensitivity and Specificity of White Blood Cells and Nitrite in Dipstick Urinalysis in Association With Urine Culture in Detecting Infection in Adults From October 2016 to October 2019 at King Abdulaziz Medical City

Background Urinary tract infection (UTI) is one of the most common clinical presentations that exhaust the patients and confuse physicians. Some of the risk factors that contribute to UTIs are age, female gender, and diabetes. Urinalysis is used to detect abnormalities in the urine, such as the presence of leukocytes, blood, and nitrite. However, urinalysis accuracy depends on the patient and the analyzer. On the other hand, urine culture is considered gold standard for diagnosing UTI. For that, the aim of this study is to determine the sensitivity of white blood cells (WBC) and nitrite in dipstick urinalysis in detecting UTI. Methods A cross-sectional study was conducted at King Abdulaziz Medical City on adult patients aged 19-65 years who underwent dipstick urinalysis and culture at the same visit from October 2016 to October 2019. The data were collected from the medical records from all the departments by using a data collection sheet through Best Care system. The sample was selected conveniently, and it was determined to be 359 patients with a confidence interval of 95%. Data were analyzed using IBM SPSS version 20 (IBM Corp., Armonk, NY, USA). Chi-square test was used to analyze the association between the outcome and the results of the dipstick urinalysis and urine culture. P-value lower than 0.05 was considered significant. Results Three hundred and fifty-nine patients were included into the study with a majority of females (81.1%) with a mean age of 47.5 years. Two hundred and fifty-two patients were culture positive, WBC sensitivity and specificity were 62.7% and 100%, and nitrite sensitivity and specificity were 20.6% and 93.5%, respectively. Ninety-nine diabetic patients were culture positive; for diabetic patients, WBC sensitivity and specificity were 65.7% and 100% and nitrite sensitivity and specificity were 18.2% and 97.6%, respectively, while for non-diabetic patients, WBC sensitivity and specificity were 60.85% and 100% and nitrite sensitivity and specificity were 22.2% and 90.8%, respectively. Conclusion Our study showed that results of WBC are more sensitive and specific than those of nitrite in comparison to the gold standard (urine culture). Diabetics and non-diabetics have slightly different results. According to our results it is difficult to depend on the dipstick urinalysis without culture. More studies are recommended in this field.