Assessing sensitivity, specificity and accuracy of a modified rapid urease kit for clinical diagnosis of Helicobacter pylori

Background: Rapid urease test is increasingly used as a cheap and quick procedure with high specificity for clinical detection of Helicobacter pylori worldwide. Objectives: To evaluate the functionality of a rapid urease kit manufactured by Pasteur institute of Iran in 2002, with some modifications compared with other common kits. During a clinical trial in Baghiatallah hospital, Tehran, the sensitivity, specificity and accuracy of the kit was investigated. Methods: This was an experimental study in which 91 patients suspected of having H pylori infection were examined. Following collection of history and clinical symptoms, the endoscopic signs of all patients were also recorded. Each endoscopic specimen was carefully examined in three ways with no previous knowledge of operator as follows: 1. Detection of urease test using modified rapid urease kit. 2. Detection of urease test using certified commercial kit. 3. Pathologic examination as the gold standard method. Findings: Regarding the results of present study, employing modified rapid urease kit produced positive results on 78.8% of pathologically positive samples. When negative pathologic samples were tested with modified kit, 89.7 % of samples found to be negative. The differences observed between the results of two tests were statistically significant (p=0.001). Using modified rapid urease kit also produced a false positive rate of 4.4%. Conclusion: Based on our data, it was shown that the sensitivity, specificity and accuracy of the modified kit were 78.8%, 89.7% and of 83.5%, respectively