Are Multiple Tests Necessary for Salivary Pepsin Detection in the Diagnosis of Laryngopharyngeal Reflux?

Objectives: To evaluate the necessity of multiple salivary pepsin tests within a day when diagnosing laryngopharyngeal reflux.

Study Design: Prospective cohort study.

Setting: Tertiary hospitals.

Methods: A total of 138 patients with signs and/or symptoms associated with laryngopharyngeal reflux were included. Salivary pepsin was detected on the day of 24-hour pH monitoring, and the results of salivary pepsin detected once in the morning and multiple times in 1 day were compared with the results of pH monitoring.

Results: Among the 138 patients, pH monitoring results were positive in 112. Salivary pepsin was positive in 47 cases in the morning, which was not consistent with the results of pH monitoring (kappa value = 0.117). With the pH monitoring results as the standard, the salivary pepsin detected once in the morning had a sensitivity of 38.4% (43/112) and a specificity of 84.6% (22/26) for the diagnosis of laryngopharyngeal reflux. When salivary pepsin was detected multiple times per day, 102 patients tested positive. The consistency with pH monitoring was moderate (kappa value = 0.587). The sensitivity was 86.6% (97/112), and the specificity was 80.8% (21/26). Of the 97 patients with positive results from pH monitoring and salivary pepsin detected multiple times a day, 54 had negative findings for a single detection in the morning, indicating that 55.7% (54/97) of the true positive cases were missed.

Conclusion: Although a single detection of salivary pepsin in the morning is more economical, the sensitivity is too low, and it is necessary to detect it multiple times a day.