Statistical analysis
Statistical analyses were performed using a R software package (http://www.r-project.org). The chi-square test was used to compare differences in categorical variables between each group. The RSI, RFS score, treatment periods, and various parameters in the 24-h MII-pH monitoring between non-responders and responders with LPR were compared using Student’s t -test. Ap -value <0.05 was considered to be statistically significant. Significantly different parameters in the 24-h MII-pH monitoring between two groups were analyzed using the receiver operating characteristic (ROC) curve to determine the cut-off value to predict responders with LPR.