Table 3 Inclusion criteria of NERD

Those who have the typical clinical symptoms of NERD, such as heartburn and reflux, persist or recur for more than 3 months, and the above symptoms have a negative impact on the quality of life of the patients.

Those who have atypical or extraesophageal symptoms, such as epigastric pain, abdominal distension, belching, non-cardiogenic chest pain, pharyngitis, cough, asthma, or foreign body sensation in the throat, which persist or recur for more than 3 months, the above symptoms have a negative impact on the patient’s quality of life: mild symptoms ≥ 2 days in a week, or moderate and severe symptoms ≥ 1 days in a week.

Reflux diagnostic questionnaire (RDQ) scale symptom score ≥ 12, which is for diagnosis of reflux diseases in the China gastroesophageal reflux Research Cooperation Group.

Those who have no esophageal mucosal lesions and Barrett esophageal manifestations by gastroscopy.

Tweny-four-hour esophageal impedance-PH monitoring: impedance records showed reflux events. At the same time, symptom association probability (SAP) is used to determine the relationship between symptoms and reflux. If SAP > 95%, symptoms will be considered related to reflux.