Diagnostic Correlation and Agreement Between the Reflux Symptom Score-12 and the Reflux Symptom Index in Vietnamese Outpatients with Suspected Laryngopharyngeal Reflux: A Preliminary Study

Objective: Clinical diagnosis of laryngopharyngeal reflux (LPR) remains challenging due to nonspecific symptoms and limited access to objective testing. While the reflux symptom index (RSI) is widely used as a symptom-based screening instrument, the newly developed reflux symptom score-12 (RSS-12) incorporates symptom severity, frequency, and quality of life impact. This study aimed to evaluate the correlation and agreement between RSS-12 and RSI in Vietnamese patients with suspected LPR. Methods: A cross-sectional study was conducted between January and October 2024. Adult outpatients with symptoms suggestive of LPR completed both the RSS-12 and the RSI questionnaires. Spearman’s correlation coefficient and Cohen’s kappa were used to assess the relationship and agreement between the 2 tools. Results: Among 102 participants (70.6% female, mean age 48.7 ± 13.9 years), the mean RSI score was 11.3 ± 7.2, with 57 patients (55.9%) scoring > 13, suggesting suspected LPR. In comparison, the mean RSS-12 score was 36.5 ± 33.7, with 71 patients (69.6%) scoring > 11, identifying a higher proportion of potential LPR cases than RSI. A strong positive correlation was found between RSI and RSS-12 scores (Spearman’s rs = 0.801, P < .001), with substantial agreement (Cohen’s κ = 0.712, P < .001). Conclusion: Reflux symptom score-12 demonstrated strong correlation and substantial agreement with RSI in identifying suspected LPR. With its broader symptom assessment and quality of life focus, RSS-12 may serve as a reliable alternative or complementary tool to RSI in routine clinical practice. However, agreement between the 2 instruments does not establish diagnostic accuracy or clinical significance.