Risk factors for gastroesophageal reflux disease, reflux esophagitis and non-erosive reflux disease among Chinese patients undergoing upper gastrointestinal endoscopic examination

Table 1 Grading of reflux esophagitis in 2278 patients

Grade	Total number	%
None	1767	79.20
A	333	14.93
B	102	4.57
C	20	0.90
D	9	0.40
Total	2231	100.00

Table 2 Complications of reflux esophagitis

	Total number	%
Barrett’s esophagus	No 1190	98.76
	Yes 15	1.24
Esophageal stenosis	No 1191	98.76
	Yes 15	1.24
Esophagorrhagia	No 1186	98.18
	Yes 22	1.82

Table 3 Comparison between upper gastrointestinal endoscopy and RDQ (χ² test)

RDQ	Endoscopy		P value
	Negative	Positive
Negative	1530	173	0.002
Positive	237	291

P = 0.002, there is significant statistical difference between the two investigations.

Table 4 Comparison between upper gastrointestinal endoscopy and RDQ (Wilcoxon rank-sum test)

RDQ	Endoscopy					Total	U value	P value
	Negative	A	B	C	D
Negative	1530	131	34	5	3	1703
Positive	237	202	68	15	6	528	3.60	0.000
Total	1767	333	102	20	9	2231

Table 5 Association between variables determined using univariate analysis: GERD (n = 701) vs non-GERD (n = 1530) patients

Variables	GERDn (%)	P value	OR	Univariate (95% CI)
				Low	High
Age (yr)
> 65	106/239 (44.40)	< 0.0001	0.53	0.41	0.70
≤ 65	595/1992 (29.90)
Gender
Male	439/1263 (34.80)	< 0.0001	0.7	0.58	0.84
Female	262/968 (27.10)
Working burden
Heavy	64/147 (43.50)	0.694	1.04	0.86	1.27
Moderate	299/975 (30.70)	0.004	0.6	0.42	0.85
Mild	282/895 (31.50)
Marital status
Divorced/ widowed	6/14 (42.90)	< 0.0001	2.05	1.49	2.82
Single	52/261 (19.90)	0.478	0.68	0.24	1.97
Married	592/1752 (33.80)
Excessive eating
Yes	245/704 (34.80)	0.009	0.77	0.63	0.94
No	372/1276 (29.20)
Routine intake of greasy food
Yes	231/618 (37.40)	< 0.0001	0.65	0.53	0.80
No	375/1347 (27.80)
Routine intake of spicy food
Yes	196/512 (38.30)	< 0.0001	0.65	0.52	0.80
No	418/1463 (28.60)
Routine intake of acidic beverage
Yes	118/358 (33.00)	0.403	0.90	0.71	1.15
No	493/1606 (30.70)
Routine intake of strong tea
Yes	149/343 (43.40)	< 0.0001	0.51	0.4	0.64
No	451/1613 (28.00)
Routine intake of sweet food
Yes	225/683 (32.90)	0.122	0.85	0.70	1.04
No	375/1269 (29.60)
Heavy smoking
Yes	209/562 (37.20)	< 0.0001	0.68	0.55	0.83
No	407/1426 (28.50)
Excessive alcohol
Yes	185/503 (36.80)	0.002	0.71	0.57	0.88
No	434/1486 (29.20)
Routine intake of coffee
Yes	26/77 (33.80)	0.529	0.86	0.53	1.39
No	568/1869 (30.40)
Constipation
Yes	122/316 (38.60)	0.002	0.68	0.53	0.87
No	489/1641 (29.80)

GERD: Gastroesophageal reflux disease.

Table 6 Association between variables determined using univariate analysis: Reflux esophagitis (n = 464) vs non-GERD (n = 1530) patients

Variables	REn (%)	P	OR	Univariate (95% CI)
				Low	High
Age (yr)
> 65	77/210 (36.70)	< 0.0001	2.09	1.55	2.82
≤ 65	387/1784 (21.70)
Gender
Male	322/1146 (28.10)	< 0.0001	1.94	1.56	2.43
Female	142/848 (16.70)
Working burden
Heavy	45/128 (35.20)	0.353	0.90	0.71	1.13
Moderate	189/865 (21.80)	0.006	1.74	1.17	2.59
Mild	191/804 (23.80)
Marital status
Divorced/ widowed	5/13 (38.50)	< 0.0001	0.48	0.33	0.70
Single	34/243 (14.00)	0.283	1.85	0.60	5.69
Married	392/1552 (25.30)
Excessive eating
Yes	147/606 (24.30)	0.346	1.12	0.89	1.41
No	259/1163 (22.30)
Routine intake of greasy food
Yes	129/516 (25.00)	0.090	1.23	0.97	1.57
No	263/1235 (21.30)
Routine intake of spicy food
Yes	112/428 (26.20)	0.037	1.31	1.02	1.69
No	283/1328 (21.30)
Routine intake of acidic beverage
Yes	76/316 (24.10)	0.593	1.08	0.81	1.44
No	326/1439 (22.70)
Routine intake of strong tea
Yes	108/302 (35.80)	< 0.0001	2.28	1.74	2.98
No	284/1446 (19.60)
Routine intake of sweet food
Yes	131/589 (22.20)	0.769	0.97	0.76	1.22
No	265/1159 (22.90)
Heavy smoking
Yes	153/506 (30.20)	< 0.0001	1.75	1.38	2.22
No	252/1271 (19.80)
Excessive alcohol
Yes	124/442 (71.90)	0.003	1.45	1.13	1.85
No	283/1335 (21.20)
Routine intake of coffee
Yes	21/72 (29.20)	0.167	1.44	0.86	2.43
No	371/1672 (22.20)
Constipation
Yes	67/261 (25.70)	0.275	1.18	0.87	1.60
No	336/1488 (22.60)

GERD: Gastroesophageal reflux disease.

Table 7 Association between variables determined using univariate analysis: NERD (n = 237) vs non-GERD (n = 1530) patients

Variables	NERDn (%)	P	OR	Univariate (95% CI)
				Low	High
Age (yr)
> 65	29/162 (17.90)	0.08	1.46	0.96	2.25
≤ 65	208/1605 (13.00)
Gender
Male	117/941 (12.40)	0.198	0.84	0.64	0.10
Female	120/826 (14.50)
Working burden
Heavy	19/102 (8.60)	0.547	1.10	0.81	1.48
Moderate	110/786 (14.00)	0.119	1.54	0.89	2.66
Mild	91/704 (12.90)
Marital status
Divorced/ widowed	1/9 (11.10)	0.007	0.5	0.30	0.83
Single	18/227 (7.90)	0.762	0.73	0.09	5.83
Married	200/1360 (14.70)
Excessive eating
Yes	98/557 (17.60)	< 0.0001	1.71	1.27	2.29
No	113/1017 (11.10)
Routine intake of greasy food
Yes	102/489 (20.90)	< 0.0001	2.29	1.71	3.07
No	112/1084 (10.30)
Routine intake of spicy food
Yes	84/400 (21.00)	< 0.0001	2.06	1.52	2.78
No	135/1180 (11.40)
Routine intake of acidic beverage
Yes	42/282 (14.900	0.41	1.17	0.81	1.68
No	167/1280 (13.00)
Routine intake of strong tea
Yes	41/235 (17.40)	0.043	1.47	1.01	2.14
No	167/1329 (12.60)
Routine intake of sweet food
Yes	94/552 (17.00)	0.001	1.67	1.24	2.25
No	110/1004 (11.00)
Heavy smoking
Yes	56/409 (13.70)	0.802	1.04	0.75	1.45
No	155/1174 (13.20)
Excessive alcohol
Yes	61/379 (16.10)	0.078	1.34	0.97	1.85
No	151/1203 (12.60)
Routine intake of coffee
Yes	5/56 (8.90)	0.36	0.65	0.26	1.64
No	197/1498 (13.20)
Constipation
Yes	55/249 (22.10)	< 0.001	2.14	1.51	3.01
No	153/1305 (11.70)

GERD: Gastroesophageal reflux disease; NERD: Non-erosive reflux disease.