Table 2.

Duration, severity, and frequency of gastro-oesophageal reflux disease symptoms* in 58 case subjects and 106 control subjects

	Heartburn				Acid regurgitation				Dysphagia
	Cases	Controls	OR†	p Value	Cases	Controls	OR†	p Value	Cases	Controls	OR†	p Value
Symptom* in previous year	71%	84%	0.46	0.071	60%	76%	0.49	0.065	52%	41%	1.57	0.226
Symptom onset
Past year	2%	8%		0.072	13%	17%		0.381	27%	21%		0.255
1–5 y ago	15%	24%	2.33		16%	27%	0.76		33%	53%	0.48
5–10 y ago	13%	23%	2.10		24%	22%	1.40		18%	7%	2.00
>10 y ago	69%	45%	5.43		47%	33%	1.87		21%	19%	0.88
Symptom frequency
Everyday	12%	33%		0.005	8%	13%		0.416	25%	23%		0.056
>1×/week	23%	32%	2.07		13%	25%	0.92		16%	16%	0.89
1×/week	12%	14%	2.42		18%	16%	1.97		9%	27%	0.31
1×/month	33%	12%	7.38		26%	18%	2.44		12%	20%	0.55
<1×/month	21%	9%	6.53		36%	27%	2.33		38%	11%	3.00
Symptom severity
Mild	43%	17%		0.006	31%	31%		0.731	37%	21%		0.129
Moderate	48%	60%	0.32		51%	45%	1.16		37%	60%	0.35
Severe	9%	22%	0.17		18%	24%	0.77		27%	9%	0.82
Symptom awakens at night	43%	57%	0.58	0.136	45%	51%	0.78	0.558
Improved with antacids	74%	70%	1.08	0.905	63%	56%	0.95	0.864

*Symptom refers to heartburn, acid regurgitation, or dysphagia.

†Crude odds ratio computed without taking any other risk factors into account.