A Comparison of the Three Objective Measures of Gastroesophageal Reflux Disease: Johnson-DeMeester Score, DeMeester Score, and Percent Time pH<4

Abstract

Purpose: The Johnson-DeMeester (JD) and DeMeester (D) scoring systems, as well as, percent total time pH < 4, have been used to determine the presence of abnormal gastroesophageal reflux (GERD) in clinical and research settings. While all methods are commonly used in practice, no prior study has compared them. The goal of this study was to compare these three objective measures of GERD in a large cohort of adult patients undergoing ambulatory 24-hour pH monitoring. Methods: A retrospective study was performed on 160 patients who underwent 24-hour pH testing off proton-pump inhibitors for at least 1 week for the evaluation of GERD. For each 24-hour pH study, both JD and D composite scores were calculated using the following parameters: percent total time pH<4, percent upright time pH<4, percent supine time pH<4, total number of reflux episodes, number of reflux episodes>5 minutes, and time of longest reflux episode. An abnormal JD score was defined as a score>22.0, and an abnormal D score defined as a score>14.7. The JD and D scores were compared to each other and in their ability to detect the presence of acid reflux expressed as the percent total time pH < 4, using a normal threshold of 4.5%. Results: The study cohort consisted of 52% (83/160) males and 66% (106/160) Caucasians, with a mean (SD) age of 46 (12) years. There was significant correlation between the JD and D composite scores (R2 0.961, p<0.001). The JD and D scores agreed in classifying normal vs. abnormal results in 96% of the studies (153/160), in which 102 study results were normal and 51 studies were abnormal by both scoring systems (kappa 0.903, p=0.000). Disagreement occurred in seven of 160 studies, primarily (4/7) due to differences in upright reflux, where the JD score was normal (range 16.9 to 20.5) and the D score was abnormal (range 14.9 to 18.5). The JD and D scores significantly correlated with percent total reflux (R2=0.793 and R2=0.919, respectively). Furthermore, the JD and D scores significantly correlated to percent upright reflux (R2 = 0.380 and R2= 0.564, respectively) and percent supine reflux (R2=0.789 and R2= 0.628, respectively). When using a value of 4.5% for the normal threshold of total percent time acid reflux, the JD score misclassifi ed 12% (19/16) of patients and the D score misclassified 8% (12/160) of patients, p=0.257. Conclusion: There was a strong agreement (kappa 0.903) between the JD score and D score in classifying a 24-hour pH test as normal or abnormal, with a significant correlation of each scoring system to percent total time pH < 4. Physicians can reliably utilize either the JD score, D score, or total percent time < pH 4 to determine if a patient has a normal or abnormal degree of acid reflux.