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.