Outpatient visit frequency in patients with overlapping non-erosive reflux disease and epigastric pain syndrome: A multicenter study

Table 1 Baseline sociodemographic and clinical characteristics of study patients with non-erosive reflux disease and epigastric pain syndrome overlap, n (%)

Variables	All patients (n = 800)
Demographic characteristics
Age, years	45
Sex (male)	300 (33.33)
BMI	22.46
Occupational category
Manual labor	191 (23.88)
Mental labor	417 (52.13)
Mixed labor	192 (24.00)
Education level
Primary school	41 (5.13)
Secondary school	281 (35.13)
Tertiary education	478 (59.75)
Primary residence
Urban	695 (86.88)
Rural	105 (13.13)
Marital status (yes)	597 (74.63)
Clinical characteristics
Smoking history (yes)	135 (16.88)
Drinking history (yes)	319 (39.88)
History of intestinal inflammation (yes)	101 (12.63)
History of abdominal surgery (yes)	74 (9.25)
Disease duration, months
NERD	17
EPS	12
Triggering factors
Dietary discomfort	583 (72.88)
Weather variation	237 (29.63)
Physical fatigue	255 (31.88)
Emotional stress	382 (47.75)
Comorbidity
Chronic pharyngitis	168 (21.00)
Cardiovascular diseases	139 (17.38)
Endocrine and metabolic diseases	148 (18.50)
Medication classes (past 3 months)
PPIs	327 (40.88)
Histamine H2-receptor antagonists	43 (5.38)
Prokinetics	88 (11.00)
Mucosal protectives	117 (14.63)
Probiotics	78 (9.75)
Chinese herbal preparations	555 (69.38)
Outpatient visits (past 3 months)
1-2 times	461 (57.63)
3-4 times	168 (21.00)
≥ 5 times	171 (21.38)
Scale scores
GERD-Q	8
PHQ-4
Asymptomatic (0-2)	421 (52.63)
Mild (3-5)	242 (30.25)
Moderate (6-8)	109 (13.63)
Severe (9-12)	28 (3.50)
PHQ-15
Asymptomatic (0-4)	205 (25.63)
Mild (5-9)	278 (34.75)
Moderate (10-14)	204 (25.50)
Severe (15-30)	113 (14.13)
SRSS
Asymptomatic (10-19)	263 (32.88)
Mild (20-29)	357 (44.63)
Moderate (30-39)	158 (19.75)
Severe (40-50)	22 (2.75)
GSRS
Mild (15-30)	336 (42.00)
Moderate (31-45)	308 (38.50)
Severe (46-60)	126 (15.75)
Very severe (> 60)	30 (3.75)

BMI: Body mass index; NERD: Non-erosive reflux disease; EPS: Epigastric pain syndrome; PPIs: Proton pump inhibitors; GERD-Q: Gastroesophageal Reflux Disease Questionnaire; PHQ: Patient Health Questionnaire; SRSS: Self-Rating Scale of Sleep; GSRS: Gastrointestinal Symptom Rating Scale.

Table 2 Univariable analysis of factors associated with gastroenterology clinic visit frequency

Variables	Statistical method (U/H/ρ)	P value
Age	0.271	< 0.001
Sex	71866.502	0.27
BMI	-0.031	0.42
Occupational category	25.893	< 0.01
Education level	6.223	0.04
Primary residence	34345.502	0.28
Marital status	42422.502	< 0.01
Smoking history	41709.502	0.14
Drinking history	73831.002	0.31
History of intestinal inflammation	31924.002	0.08
History of abdominal surgery	24378.502	0.14
Disease duration of NERD	0.141	< 0.001
Disease duration of EPS	0.001	0.96
Comorbidity
Chronic pharyngitis	44300.002	< 0.001
Cardiovascular diseases	33179.502	< 0.01
Endocrine and metabolic diseases	42482.502	0.01
Triggering factors
Dietary discomfort	62988.502	0.92
Weather variation	65791.002	0.73
Physical fatigue	65318.002	0.12
Emotional stress	77004.502	0.33
Medication classes (past 3 months)
PPIs	66776.502	< 0.01
Histamine H2-receptor antagonists	14127.002	0.10
Prokinetics	25797.502	< 0.01
Mucosal protectives	33508.002	< 0.01
Probiotics	22819.502	< 0.01
Chinese herbal medicine	39091.002	< 0.001
GERD-Q	0.091	0.01
PHQ-4	0.131	< 0.001
PHQ-15	0.131	< 0.001
SRSS	0.171	< 0.001
GSRS	0.151	< 0.001

¹Spearman’s correlation coefficient.

²Mann-Whitney U test.

³Kruskal-Wallis H test.

BMI: Body mass index; NERD: Non-erosive reflux disease; EPS: Epigastric pain syndrome; PPIs: Proton pump inhibitors; GERD-Q: Gastroesophageal Reflux Disease Questionnaire; PHQ: Patient Health Questionnaire; SRSS: Self-Rating Scale of Sleep; GSRS: Gastrointestinal Symptom Rating Scale.

Table 3 Multivariable ordinal logistic regression analysis of factors independently associated with higher outpatient visit frequency

Variables	OR (adjusted)	95%CI	P value
Age	1.02	1.00-1.04	0.02
Disease duration of NERD	1.004	1.001-1.007	< 0.01
GERD-Q	1.00	0.94-1.06	0.95
PHQ-4	1.08	1.01-1.16	0.02
PHQ-15	0.96	0.92-1.01	0.14
SRSS	1.03	1.00-1.05	0.06
GSRS	1.00	0.98-1.02	0.88
Mixed labor	3.37	2.11-5.40	< 0.001
Manual labor	1.91	1.22-3.00	0.01
Primary school	1.31	0.64-2.69	0.46
Secondary school	0.95	0.6-1.39	0.77
Married	2.05	1.27-3.30	< 0.01
PPIs	1.39	1.00-1.94	0.05
Prokinetics	1.12	0.70-1.80	0.63
Mucosal protectives	1.53	0.99-2.35	0.05
Probiotics	1.39	0.87-2.27	0.19
Chinese herbal preparations	6.64	4.31-10.24	< 0.001
Chronic pharyngitis	1.18	0.82-1.70	0.38
Cardiovascular diseases	1.72	1.12-2.64	0.01
Endocrine and metabolic diseases	0.88	0.60-1.31	0.53

For disease duration of non-erosive reflux disease, adjusted odds ratio and 95% confidence interval are presented with three decimal places to accurately reflect the precise values (adjusted odds ratio = 1.004, 95% confidence interval: 1.001-1.007), as rounding to two decimal places would incorrectly display as 1.00 and suggest no association. OR: Odds ratio; CI: Confidence interval; NERD: Non-erosive reflux disease; GERD-Q: Gastroesophageal Reflux Disease Questionnaire; PHQ: Patient Health Questionnaire; SRSS: Self-Rating Scale of Sleep; GSRS: Gastrointestinal Symptom Rating Scale; PPIs: Proton pump inhibitors.

Table 4 Interaction effects between significant predictors on outpatient visit frequency

Variables	OR (adjusted)	95%CI	P value
PPIs × age	0.99	0.97-1.01	0.23
PPIs × disease duration of NERD	1.00	0.99-1.00	0.38
PPIs × PHQ-4	1.02	0.92-1.14	0.65
Chinese herbal preparations × PHQ-4	0.95	0.83-1.08	0.39
PPIs × Chinese herbal preparations1	29.06	8.38-100.72	< 0.001
PPIs × Chinese herbal preparations2	3.03	0.72-12.76	0.13

¹Comparison of outpatient visits (past 3 months) 1-2 times vs 3-4 times.

²Comparison of outpatient visits (past 3 months) 3-4 times vs ≥ 5 times.

OR: Odds ratio; CI: Confidence interval; PPIs: Proton pump inhibitors; NERD: Non-erosive reflux disease; PHQ: Patient Health Questionnaire.