When considering the pros and cons of PPI testing in an Asian population, the major pro is that there will be a high prevalence of poor or intermediate metabolizers who may have an increased serum level of PPI, resulting in a higher sensitivity, lower required dose of PPI, and less cost in testing. The con is mainly related to the increased proportion of ENRD patients. Up to 50% of ENRD patients, whose condition is termed functional heartburn, report sufficient heartburn relief with PPI treatment.[6][11] Therefore, a higher proportion of false positive cases may occur, which can lead to a decrease in test specificity.