Development and validation of a simple and multifaceted instrument, GERD-TEST, for the clinical evaluation of gastroesophageal reflux and dyspeptic symptoms

Table 1 Gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test

Q1. Have you been bothered by heartburn during the past week? (By heartburn we mean a burning pain or discomfort behind the breastbone in your chest)
Q2. Have you been bothered by acid regurgitation during the past week? (By acid regurgitation we mean regurgitation or flow of sour or bitter fluid into your mouth)
Q3. Have you been bothered by epigastric pain or burning during the past week? (Epigastric pain includes any type of pain of the stomach)
Q4. Have you been bothered by postprandial fullness during the past week? (Postprandial fullness refers to discomfort or a sensation of heaviness caused by the food you consume remaining in the stomach)
Q5. Have you been bothered by early satiation during the past week? (Early satiation refers to the inability to finish a normally sized meal)
Response scale for Q1-5:
1 = no discomfort at all, 2 = slight discomfort, 3 = mild discomfort, 4 = moderate discomfort, 5 = moderately severe discomfort, 6 = severe discomfort, 7 = very severe discomfort.
Q6. During the past week, how often have you felt dissatisfaction because you were unable to eat meals as you intended due to chest and stomach symptoms? (Not being able to eat as you intended refers to the inability to eat the sufficient amount of food you want to eat at an uninhibited, natural pace)
Q7. During the past week, how often have you felt dissatisfaction due to impaired sleep caused by chest and stomach symptoms?
Q8. During the past week, how often have you felt dissatisfaction due to impairment of your work, housework, or other daily activities caused by chest and stomach symptoms?
Q9. During the past week, how often have you felt dissatisfaction because you were in a bad mood due to chest and stomach symptoms?
Response scale for Q.6-9:
1 = not at all, 2 = slightly, 3 = moderately, 4 = quite a lot, 5 = extremely.
Q10. During the past week, how often have you wanted another drug in addition to the drug your doctor prescribed because of intense symptoms of heartburn and acid regurgitation?
1 = not at all, 2 = on 1 d, 3 = on 2 to 3 d, 4 = on 4 to 5 d, 5 = always.
Q11. During the past week, how have you felt about symptoms of heartburn and acid regurgitation as compared with the symptom severity before current treatment?
1 = extremely improved, 2 = improved, 3 = slightly improved, 4 = not changed, 5 = aggravated.
Q12. If 10 corresponds to your symptoms before current treatment and 0 is "symptom-free", what number corresponds to symptoms of heartburn and acid regurgitation during the past week? Please circle the applicable score below:
			0	………….. 1 ………….. 2 ………..... 3 ………..... 4….…….... 5 ………..... 6 ….……... 7 …..……... 8 ….…….... 9 ……….....	10
			|		|
			Symptom-free		Symptoms before current treatment
Q13. What proportion of the proton pump inhibitor prescribed to you did you take as instructed?
1 = took drug as instructed, 2 = generally took drug as instructed (took at least three-quarters of the drug prescribed), 3 = sometimes forgot (took at least half but less than three-quarters of the drug prescribed, 4 = took little (took less than half of the drug prescribed), 5 = did not take any.

Before therapy, questions about treatment efficacy and adherence (Q10–Q13) were excluded. The following scores were defined: Score of GERD symptom subscale (GERD-SS) = (Q1 + Q2)/2; Score of Epigastric pain/burning symptom (EPS-Sx) = Q3; Score of Postprandial distress symptom subscale (PDS-SS) = (Q4 + Q5)/2; Score of FD symptom subscale (FD-SS) = [Q3 + (Q4 + Q5)/2]/2; Score of dissatisfaction with daily life subscale (DS-SS) = (Q6 + Q7 + Q8 + Q9)/4; Residual symptom rate (%) = 100 × (GERD-SS score at 4 wk-1)/(GERD-SS score at 0 wk-1). GERD: Gastroesophageal reflux and dyspepsia-therapeutic efficacy; FD: Functional dyspepsia.

Table 2 Patients' characteristics n (%)

	At baseline (n = 290)	Accomplished 4W
		PPI Tx (n = 198)
Age (mean ± SD, yr)	57.5 ± 13.9	57.9 ± 13.1
Sex
Male	178 (61)	126 (64)
Female	112 (39)	72 (36)
BMI (mean ± SD, kg/m2)	24.0 ± 3.9	24.2 ± 4.1
Endoscopic findings
NERD	107 (37)	64 (32)
Grade N	62 (21)	38 (19)
Grade M	45 (16)	26 (13)
ERD	183 (63)	134 (68)
Grade A	94 (32)	66 (33)
Grade B	60 (21)	47 (24)
Grade C	21 (7)	14 (7)
Grade D	8 (3)	7 (4)

NERD: Nonerosive reflux disease; ERD: Erosive reflux disease; PPI: Proton pump inhibitor.

Table 3 Internal consistency of each subscale for the gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test (n = 290)

Subscales	Cronbach's α
GERD-SS	0.78
Heartburn
Acid regurgitation
FD-SS	0.75
Epigastric pain/burning
Postprandial fullness
Early satiation
Dissatisfaction for daily life SS	0.82
Dissatisfaction for eating
Dissatisfaction for sleeping
Dissatisfaction for daily activity
Dissatisfaction for the mood

GERD: Gastroesophageal reflux and dyspepsia-therapeutic efficacy; FD: Functional dyspepsia.

Table 4 Pearson's r value of gastroesophageal reflux and dyspepsia therapeutic efficacy and satisfaction test scores with physical component summary and mental component summary of SF-8 and symptom scores with DS (before treatment; n = 290)

	PCS		MCS		Q6. Eating		Q7. Sleeping		Q8. Daily activity		Q9. Mood
	r	P value	r	P value	r	P value	r	P value	r	P value	r	P value	r	P value
Q1. Heartburn	-0.267	< 0.0001	-0.236	< 0.0001	0.331	< 0.0001	0.420	< 0.0001	0.479	< 0.0001	0.560	< 0.0001	0.558	< 0.0001
Q2. Acid regurgitation	-0.214	0.0003	-0.193	0.0012	0.379	< 0.0001	0.406	< 0.0001	0.458	< 0.0001	0.498	< 0.0001	0.553	< 0.0001
GERD-SS	-0.266	< 0.0001	-0.238	< 0.0001	0.393	< 0.0001	0.457	< 0.0001	0.517	< 0.0001	0.585	< 0.0001	0.614	< 0.0001
Q3. Epigastric pain or burning	-0.311	< 0.0001	-0.327	< 0.0001	0.452	< 0.0001	0.445	< 0.0001	0.483	< 0.0001	0.520	< 0.0001	0.595	< 0.0001
Q4. Postprandial fullness	-0.173	0.0037	-0.402	< 0.0001	0.554	< 0.0001	0.317	< 0.0001	0.448	< 0.0001	0.510	< 0.0001	0.568	< 0.0001
Q5. Early satiation	-0.222	0.0002	-0.354	< 0.0001	0.716	< 0.0001	0.336	< 0.0001	0.440	< 0.0001	0.463	< 0.0001	0.606	< 0.0001
FD-SS	-0.305	< 0.0001	-0.424	< 0.0001	0.658	< 0.0001	0.468	< 0.0001	0.560	< 0.0001	0.611	< 0.0001	0.716	< 0.0001
Q6. Eating	-0.307	< 0.0001	-0.378	< 0.0001
Q7. Sleeping	-0.216	0.0003	-0.407	< 0.0001
Q8. Daily activity	-0.356	< 0.0001	-0.494	< 0.0001
Q9. Mood	-0.307	< 0.0001	-0.496	< 0.0001
Dissatisfaction for daily life-SS	-0.370	< 0.0001	-0.553	< 0.0001
	Effect size	Small	Medium	Large
	r	0.1 ≤	0.3 ≤	0.5 ≤

GERD-TEST: Gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test; PCS: Physical component summary; MCS: Mental component summary; FD: Functional dyspepsia.

Table 5 Comparison of gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test scores before and after 4 wk of proton pump inhibitor treatment (n = 198)

	Before Tx		After 4 wk PPI Tx		Cohen's d	P value
	mean	SD	mean	SD
Q1. Heartburn	3.64	1.31	1.77	0.97	1.63	< 0.0001
Q2. Acid regurgitation	3.17	1.37	1.66	0.95	1.29	< 0.0001
GERD-SS	3.40	1.20	1.71	0.91	1.59	< 0.0001
Q3. Epigastric pain or burning	3.11	1.40	1.75	1.02	1.11	< 0.0001
Q4. Postprandial fullness	3.05	1.34	1.95	1.06	0.91	< 0.0001
Q5. Early satiation	2.25	1.34	1.76	0.91	0.42	< 0.0001
FD-SS	2.88	1.13	1.80	0.85	1.08	< 0.0001
Q6. Eating	1.97	1.07	1.41	0.74	0.61	< 0.0001
Q7. Sleeping	2.14	1.07	1.29	0.63	0.97	< 0.0001
Q8. Daily activity	1.98	1.00	1.33	0.67	0.76	< 0.0001
Q9. Mood	2.55	1.06	1.57	0.80	1.05	< 0.0001
Dissatisfaction for daily life-SS	2.15	0.84	1.40	0.59	1.04	< 0.0001
	Effect size	Small	Medium	Large
	Cohen's d	0.2 ≤	0.5 ≤	0.8 ≤
	r	0.1 ≤	0.3 ≤	0.5 ≤

GERD-TEST: Gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test; PPI: Proton pump inhibitor; FD: Functional dyspepsia.

Table 6 Comparison of the gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test scores between responders and non-responders based on a "residual symptom rate ≤ 50%" definition

	Before Tx						After 4 wk PPI Tx						Δ (0W-4W)
Responder definition by	Responder (n = 153)		Non-responder (n = 41)		Cohen's d	P value	Responder (n = 153)		Non-responder (n = 41)		Cohen's d	P value	Responder (n = 153)		Non-responder (n = 41)		Cohen's d	P value
Residual Sx 50% ≥	mean	SD	mean	SD			mean	SD	mean	SD			mean	SD	mean	SD
Q1. Heartburn	3.79	1.29	3.34	1.09	0.36	0.025	1.45	0.61	3.05	1.07	2.21	< 0.0001	-2.34	1.24	-0.29	0.87	1.76	< 0.0001
Q2. Acid regurgitation	3.31	1.32	2.85	1.37	0.34	0.060	1.37	0.57	2.78	1.24	1.86	< 0.0001	-1.93	1.25	-0.07	1.17	1.51	< 0.0001
GERD-SS	3.55	1.19	3.10	0.99	0.39	0.014	1.41	0.53	2.91	1.08	2.21	< 0.0001	-2.14	1.11	-0.18	0.71	1.89	< 0.0001
Q3. Epigastric pain or burning	3.12	1.42	3.27	1.18	-	0.509	1.51	0.84	2.73	1.10	1.36	< 0.0001	-1.61	1.41	-0.54	1.03	0.81	< 0.0001
Q4. Postprandial fullness	3.05	1.39	3.15	1.15	-	0.636	1.79	0.96	2.61	1.18	0.81	< 0.0001	-1.25	1.32	-0.54	1.16	0.56	0.001
Q5. Early satiation	2.26	1.38	2.28	1.20	-	0.950	1.66	0.85	2.17	1.05	0.57	0.004	-0.60	1.13	-0.10	0.90	0.46	0.003
FD-SS	2.89	1.17	2.98	0.94	-	0.622	1.62	0.74	2.56	0.85	1.24	< 0.0001	-1.27	1.06	-0.42	0.82	0.84	< 0.0001
Q6. Eating	1.95	1.05	2.07	1.15	-	0.550	1.34	0.69	1.68	0.88	0.47	0.023	-0.61	0.88	-0.39	1.02	0.25	0.206
Q7. Sleeping	2.17	1.08	2.05	1.05	-	0.514	1.18	0.49	1.66	0.88	0.80	0.001	-0.99	1.02	-0.39	0.86	0.61	0.000
Q8. Daily activity	1.99	1.03	1.98	0.89	-	0.909	1.24	0.6	1.68	0.82	0.68	0.001	-0.75	1.05	-0.30	0.85	0.45	0.005
Q9. Mood	2.60	1.07	2.46	0.98	-	0.433	1.43	0.74	2.10	0.83	0.88	< 0.0001	-1.17	1.06	-0.37	0.80	0.80	< 0.0001
Dissatisfaction for daily life-SS	2.18	0.83	2.11	0.84	-	0.650	1.30	0.52	1.78	0.69	0.86	< 0.0001	-0.88	0.77	-0.36	0.64	0.71	< 0.0001
	Effect size	Small	Medium	Large
	Cohen's d	0.2 ≤	0.5 ≤	0.8 ≤

GERD-TEST: Gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test; PPI: Proton pump inhibitor.

Table 7 Comparison of gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test scores between responders and non-responders based on a "patient's impression of improved or better" definition

	Before Tx						After 4 wk PPI Tx						Δ (0W-4W)
Responder definition by	Responder (n = 155)		Non-responder (n = 39)		Cohen's d	P value	Responder (n = 155)		Non-responder (n = 39)		Cohen's d	P value	Responder (n = 155)		Non-responder (n = 39)		Cohen's d	P value
Patients' impression improved ≤	mean	SD	mean	SD			mean	SD	mean	SD			mean	SD	mean	SD
Q1. Heartburn	3.72	1.31	3.41	1.25	-	0.169	1.62	0.88	2.38	1.14	0.82	0.000	-2.10	1.42	-1.03	1.25	0.78	< 0.0001
Q2. Acid regurgitation	3.30	1.39	2.69	1.20	0.45	0.007	1.55	0.86	2.05	1.19	0.53	0.015	-1.74	1.39	-0.64	1.44	0.79	< 0.0001
GERD-SS	3.51	1.23	3.05	1.01	0.39	0.017	1.59	0.83	2.22	1.08	0.71	0.001	-1.92	1.29	-0.83	1.10	0.87	< 0.0001
Q3. Epigastric pain or burning	3.17	1.42	2.92	1.31	-	0.306	1.65	0.98	2.15	1.16	0.50	0.014	-1.52	1.45	-0.77	1.11	0.54	0.001
Q4. Postprandial fullness	3.04	1.39	3.13	1.22	-	0.691	1.88	1.07	2.26	1.04	0.36	0.045	-1.16	1.33	-0.87	1.28	0.22	0.212
Q5. Early satiation	2.23	1.38	2.33	1.24	-	0.662	1.67	0.88	2.13	0.98	0.51	0.008	-0.56	1.13	-0.21	0.95	0.33	0.044
FD-SS	2.90	1.17	2.83	0.97	-	0.697	1.71	0.84	2.17	0.83	0.55	0.002	-1.19	1.10	-0.65	0.86	0.51	0.001
Q6. Eating	1.99	1.08	1.90	1.07	-	0.641	1.35	0.70	1.67	0.87	0.43	0.036	-0.64	0.89	-0.23	0.90	0.46	0.013
Q7. Sleeping	2.12	1.08	2.21	1.08	-	0.646	1.23	0.58	1.56	0.79	0.55	0.013	-0.89	1.04	-0.64	0.93	0.25	0.146
Q8. Daily activity	1.98	1.01	1.97	0.97	-	0.968	1.26	0.63	1.67	0.74	0.63	0.002	-0.72	1.02	-0.32	0.96	0.41	0.021
Q9. Mood	2.57	1.07	2.51	1.05	-	0.771	1.50	0.8	1.87	0.77	0.47	0.007	-1.07	1.06	-0.64	1.01	0.41	0.020
Dissatisfaction for daily life-SS	2.16	0.84	2.12	0.84	-	0.768	1.33	0.57	1.69	0.63	0.62	0.001	-0.83	0.77	-0.45	0.68	0.50	0.003
	Effect size	Small	Medium	Large
	Cohen's d	0.2 ≤	0.5 ≤	0.8 ≤

GERD-TEST: Gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test; PPI: Proton pump inhibitor.

Table 8 Comparison of gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test scores between responders and non-responders based on a "numeric rating scale ≤ 5" definition

	Before Tx						After 4 wk PPI Tx						Δ (0W-4W)
Responder definition by	Responder (n = 176)		Non-responder (n = 19)		Cohen's d	P value	Responder (n = 176)		Non-responder (n = 19)		Cohen's d	P value	Responder (n = 176)		Non-responder (n = 19)		Cohen's d	P value
NRS 5 ≥	mean	SD	mean	SD			mean	SD	mean	SD			mean	SD	mean	SD
Q1. Heartburn	3.68	1.32	3.11	0.99	0.45	0.022	1.69	0.89	2.37	1.30	0.73	0.027	-1.99	1.42	-0.74	1.15	0.90	< 0.0001
Q2. Acid regurgitation	3.19	1.37	2.95	1.22	-	0.423	1.56	0.84	2.32	1.16	0.87	0.006	-1.63	1.39	-0.63	0.83	0.75	< 0.0001
GERD-SS	3.43	1.21	3.03	1.02	-	0.106	1.62	0.81	2.34	1.21	0.85	0.012	-1.81	1.27	-0.68	0.87	0.91	< 0.0001
Q3. Epigastric pain or burning	3.08	1.38	3.11	1.41	-	0.940	1.66	0.95	2.37	1.21	0.73	0.014	-1.42	1.40	-0.74	1.37	0.49	0.040
Q4. Postprandial fullness	3.04	1.35	3.00	1.25	-	0.896	1.90	1.05	2.42	1.12	0.50	0.053	-1.14	1.32	-0.58	1.17	0.43	0.051
Q5. Early satiation	2.22	1.33	2.32	1.29	-	0.753	1.69	0.89	2.26	0.93	0.64	0.012	-0.53	1.06	-0.05	1.03	0.45	0.058
FD-SS	2.85	1.13	2.88	1.02	-	0.899	1.73	0.82	2.36	0.82	0.77	0.002	-1.13	1.08	-0.53	0.83	0.57	0.004
Q6. Eating	1.94	1.05	1.89	0.99	-	0.841	1.35	0.69	1.63	0.68	0.40	0.095	-0.59	0.92	-0.26	0.81	0.36	0.101
Q7. Sleeping	2.10	1.05	2.21	1.08	-	0.679	1.23	0.55	1.84	1.01	1.02	0.010	-0.88	1.00	-0.37	0.90	0.51	0.022
Q8. Daily activity	1.97	1.01	2.00	0.94	-	0.881	1.26	0.59	1.95	0.91	1.10	0.001	-0.71	1.04	-0.05	0.40	0.67	< 0.0001
Q9. Mood	2.55	1.08	2.42	0.84	-	0.534	1.51	0.78	2.05	0.85	0.70	0.008	-1.05	1.08	-0.37	0.50	0.65	< 0.0001
Dissatisfaction for daily life-SS	2.13	0.83	2.13	0.84	-	0.989	1.34	0.53	1.87	0.77	0.95	0.004	-0.81	0.78	-0.26	0.43	0.73	< 0.0001
	Effect size	Small	Medium	Large
	Cohen's d	0.2 ≤	0.5 ≤	0.8 ≤

GERD-TEST: Gastroesophageal reflux and dyspepsia-therapeutic efficacy and satisfaction test; PPI: Proton pump inhibitor.

Table 9 Type of symptoms responding to the therapeutic efficacy as assessed by the patients (Multivariate analysis)

	Q11. Patient's impression		Q12. Numeric rating scale
	β	P value	β	P value
ΔGERD-SS (0-4 wk)	0.371	< 0.0001	0.411	< 0.0001
ΔFD-SS (0-4 wk)	0.037	0.6541	-0.092	0.2656
R2 (P value)	0.155	< 0.0001	0.133	< 0.0001
	Effect size	Small	Medium	Large
	β	0.1 ≤	0.3 ≤	0.5 ≤
	R2	0.02 ≤	0.13 ≤	0.26 ≤