This multicenter prospective observational study was conducted in 29 institutions in Japan. One or more investigators per institution were members of the GERD Society, a Japanese collaborative research group comprised of experts in the clinical practice of GERD treatment. This study was conducted in accordance with the Declaration of Helsinki (sixth revision, 2008) after obtaining approval from the ethics committee of each institution or the central ethics committee of Nishi Clinic, Osaka, Japan. The study was registered with the University Hospital Medical Information Network Center Clinical Trials Registry in Japan (reference number UMIN000006614).
The study design is shown in Fig. 5. Eligible patients were asked to complete the following questionnaires to assess the clinical characteristics of the patients. GERD/DF symptoms and quality of life were assessed using the GERD-TEST17 and the SF-818 at weeks 0, 2, and 4. Psychiatric assessments were performed using the HADS19 at weeks 0 and 4. All questionnaires were completed by the study participants themselves and mailed to the data center.
Outpatients with symptoms of gastroesophageal reflux were included in this study. Patients were considered to have symptoms of gastroesophageal reflux disease if they had moderate or severe heartburn or acid regurgitation at least once a week or mild heartburn or acid regurgitation at least twice times a week during the 2 weeks preceding this study, according to the Montreal definition20. After upper gastrointestinal endoscopy, patients received a PPI at the dose approved in Japan; i.e. omeprazole 20 mg once daily, lansoprazole 30 mg once daily or rabeprazole 10 or 20 mg once daily.
Eligibility criteria were (1) an endoscopic diagnosis of LA grade N, M or A GERD according to the modified LA classification system (Fig. 6)6; (2) age > 20 at time of consent; and (3) providing written informed consent.
Exclusion criteria were (1) concurrent or prior illnesses that may affect study results (eg, Zollinger-Ellison syndrome, inflammatory bowel disease, irritable bowel syndrome, esophageal stricture, eosinophilic esophagitis, esophageal achalasia, malabsorption, cerebrovascular disease); (2) vomiting associated with other illnesses, peptic ulcers except in the scarring stage, or other symptoms of severe liver disease, kidney disease, heart disease, psychiatric illness, metabolic, neurological or collagen disease; (3) confirmed or suspected malignancy; (4) history of gastrointestinal surgery or vagotomy; (5) history of hypersensitivity to PPIs or their excipients; (6) eradication of H. pylori within 6 months prior to enrolment; (7) pregnancy, possible pregnancy or breastfeeding; (8) medications with a PPI or histamine type 2 receptor antagonist within the week prior to enrollment; and (9) study ineligibility as determined by the physician. Prohibited drugs were those that could affect study results (PPIs, histamine type 2 receptor antagonists, prokinetic agents, gastric mucosal protectants, and anticholinergics other than the study drug) and those that could interact with any of the study drugs.
Details of questionnaires for data collection
The GERD-TEST is a 13-item patient-reported questionnaire developed to investigate the symptoms of GERD and dyspepsia, their impact on the patient’s daily life, and the patient’s impression of the treatment. GERD-SS is defined as the mean of heartburn (Q1) and acid regurgitation (Q2) scores, and the FD symptom subscale (FD-SS) is defined as the mean of pain symptoms /heartburn (Q3) and postprandial distress. symptoms [postprandial fullness (Q4) and early satiation (Q5)]. The DS-SS is divided into dissatisfaction with food (Q6), dissatisfaction with sleep (Q7), dissatisfaction with daily activity (Q8), and dissatisfaction with mood (Q9). Questions 10 to 13 are about the effects of PPI treatment. The details of the GERD-TEST were discussed in our previous report21.
The SF-8 is a questionnaire used to assess the health status of patients and consists of a summary of the physical component and a summary of the mental component22. Further details about the SF-8 have already been reported22.
The HADS is a well-established measure of psychiatric bias with subscales for anxiety and depression, each comprising seven items19. A higher score indicates a higher level of anxiety or depression. Anxiety and depression scores were compared between the three groups in the present study.
Therapeutic Response to PPI Treatment
The efficacy of PPI therapy in patients with GERD was assessed using the following three indices, as previously reported21: (1) the rate of residual GERD-SS symptoms: 100 (%) × (GERD-SS score week 4 − 1)/(GERD-SS score week 0 − 1), (2) the impression that the patient has treatment: Q11 score on GERD-TEST (score of feeling that GERD symptoms have improved compared to before current drug; 1 = much improved, 2 = improved, 3 = somewhat improved, 4 = no change and 5 = worse), and (3) GERD Symptom Numerical Rating Scale score (GERD Test Q12): a numeric rating of the relative intensity of GERD symptoms (0 points = no symptoms, 10 points = same severity of symptoms as before treatment).
Data from patients who underwent upper GI endoscopy; questionnaires completed within 4 weeks prior to the start of treatment; provided information on sex, age, height and body weight; and had a treatment compliance rate ≥ 75% were analyzed. Patients with symptoms of gastroesophageal reflux were divided into three groups according to endoscopic findings: LA grade N, LA grade M and LA grade A. Data are expressed as mean ± standard deviation. The statistical methods used to compare patient characteristics and treatment effects among the three groups were analysis of variance followed by Tukey’s test and Fisher’s exact test. The size of the difference between the groups was assessed by the effect size (Cohen’s D). Cohen D values ≥0.20, ≥0.50, and ≥0.80 were defined as small, medium, and large effects, respectively23. JMP12.0.1 software (SAS Institute Inc., Cary, NC, USA) was used for data analysis, and a p a value
Ethical approval and consent to participate and publish
All procedures complied with the ethical standards of the committee responsible for human experimentation (institutional and national) and the Declaration of Helsinki of 1964 and later versions. Informed consent or a proxy was obtained from all patients for their participation in the study.