Optimal Timing of the Salivary Pepsin Test for the Diagnosis of Laryngopharyngeal Reflux.

Objective: To investigate the optimal time point for diagnosing laryngopharyngeal reflux (LPR) through combining 24‐h hypopharyngeal‐esophageal multichannel intraluminal impedance‐pH (24‐h HEMII‐pH) monitoring and the multi‐time point salivary pepsin test (MTPSPT). Study Design: Prospective uncontrolled trial. Method: Patients with and without LPR symptoms were included as the test group and the control group, respectively. The patients in the test group underwent 24‐h HEMII‐pH and MTPSPT. The results of 24‐h HEMII‐pH were used as a diagnostic criterion for LPR, and the diagnostic value of salivary pepsin tests performed at different time points was compared by receiver operating characteristic (ROC) analysis. Results: A total of 153 patients were included. Based on 24‐h HEMII‐pH, the positive rate of LPR in the test group of patients was 84.00%. In the control group, only one person (3.57%) had a positive salivary pepsin test result. The area under the curve (AUC) of the MTPSPT was 0.827. In addition, we separately calculated the AUC of the combined salivary pepsin test at different time points, and found good diagnostic value (AUC = 0.799) when the test was combined with the waking, 1 and 2 h after breakfast and lunch, and 1 h after dinner tests. However, when the number of tests were further increased, the diagnostic value did not improve significantly. Conclusion: Salivary pepsin testing combined with waking, 1 h and 2 h after breakfast and lunch, and 1 h after dinner has almost the same diagnostic value as MTPSPT, and testing at these time points can be an effective method for diagnosing LPR. Level of Evidence: 3 Laryngoscope, 133:1706–1711, 2023 [ABSTRACT FROM AUTHOR]