Study design, setting, and participants
Patients who visited a tertiary care otolaryngology clinic with LPR symptoms were investigated prospectively. In this study, sticking or lump sensation in the throat, troublesome cough, frequent throat clearing, and hoarseness or voice problems, were defined as LPR symptoms. Patients were examined with laryngoscopy by an ENT specialist during routine laryngeal examination, and LPR-related findings, such as ventricular obliteration, subglottic edema, thick endolaryngeal mucous, and posterior commissure hypertrophy were noted. Laryngeal endoscopic findings were recorded using the reflux finding score (RFS) to assess clinical severity of each patient.7
Inclusion criteria were age between 19 and 75 years and safe tolerance to unsedated laryngoscopy. Patients with history of malignancy or radiotherapy in head and neck region, and current pregnancy were excluded in this study. Patients with LPR symptoms matching the aforementioned criteria underwent 24-h MII-pH monitoring. All patients were instructed to discontinue PPI intake for 2 weeks and antacid or H2 blocker intake for 1 week before 24-h MII-pH monitoring. They were advised lifestyle changes and prescribed high-dose PPIs twice (30 min before meals) daily for at least 2 months. Patients lost to follow-up within 2 months were excluded from this study.
All patients completed the reflux symptom index (RSI) questionnaire before treatment and during the monthly visit during treatment. The RSI is a highly validated survey with nine questions to assess the level of severity of LPR and estimate the response to treatment. It estimates the level of symptoms and their severity through a 6-point Likert scale, which ranges from 0 to 5. A high score indicates more severe symptoms, whereas 0 indicates no symptom.8
Patients with suspected LPR were classified into those with LPR (proximal all reflux episodes ≥1) and those with no reflux (proximal all reflux episodes = 0). Patients with LPR were divided into non-responders and responders according to the improvement of subjective symptoms in the RSI questionnaire. Those showing a ≥50% decrease in the follow-up RSI score compared to the pre-treatment RSI score during treatment were defined as responders; others were defined as non-responders.