Poor consistency between reflux symptom index and laryngopharyngeal pH monitoring in laryngopharyngeal reflux diagnosis in Chinese population

BACKGROUND: It is unknown whether the reflux symptom index (RSI) can replace pH monitoring as a diagnostic tool for laryngopharyngeal reflux (LPR) in Chinese people. The relationships between reflux parameters and LPR symptoms also require further research. METHODS: A total of 216 Chinese patients underwent laryngopharyngeal pH monitoring and filled out an RSI questionnaire. Laryngopharyngeal pH monitoring indicated a diagnosis of LPR for patients with 7 or more episodes of reflux or a reflex area index (RAI) of 6.3 or more. The RSI questionnaire indicated a diagnosis of LPR for patients with RSI scores of 14 or higher. RESULTS: Of the 216 patients, 85 were diagnosed with LPR as assessed by the RSI, and 72 were diagnosed with LPR through laryngopharyngeal pH monitoring. The Cohen's kappa coefficient comparing LPR diagnosis consistency between RSI score and laryngopharyngeal pH monitoring was 0.133 (P=0.007). This indicated the two diagnostic methods were consistent to a low degree; the total consistency rate was only 59.7% (129/216). The sensitivity of the RSI was 48.6% (35/72), and its specificity was 82.5% (94/114). For convenience, we named the nine symptom groups in the RSI sequentially as P1-P9. P1, P2, P3, P5, P6, and P7 were all correlated with at least one reflux parameter (P<0.05), but P4, P8, and P9 were not correlated with any reflux parameters (P>0.05). A total of 72 patients were diagnosed using pH monitoring, the gold standard for LPR diagnosis. The most common symptoms of LPR were found to be P9, P3, P8, P7, and P2 in these patients. The symptoms that most seriously affected patients were P9, P8, P3, P7, and P2. CONCLUSIONS: The consistency in diagnosis of LPR between the RSI and laryngopharyngeal pH monitoring was poor, meaning the RSI is not a suitable LPR initial screening tool and cannot replace pH monitoring. Additionally, reflux symptoms P4, P8, and P9 were not correlated with any reflux parameters. The most prevalent LPR symptom was P9, followed by P3, P8, P7, and P2. The most severe symptom was also P9, followed by P8, P3, P7, and P2.