Table 3.

Scores for each question of GerdQ in CDQ-positive and -negative participants

	Web-based population			Mail-survey population
	CDQ < 6 (n = 135)	CDQ ≥ 6 (n = 227)	p-value	CDQ < 6 (n = 40)	CDQ ≥ 6 (n = 87)	p-value
GerdQ
1. How often did you have a burning feeling behind your breastbone (heartburn)?	0.38 ± 0.71	0.96 ± 0.89	<0.001	0.14 ± 0.50	0.84 ± 0.93	<0.001
2. How often did you have stomach contents (liquid or food) moving upwards to your throat or mouth (regurgitation)?	0.36 ± 0.63	0.68 ± 0.80	<0.001	0.26 ± 0.64	0.83 ± 0.92	<0.001
3. How often did you have a pain in the centre of the upper stomach?	2.65 ± 0.70	2.42 ± 0.83	<0.001	2.66 ± 0.74	2.29 ± 0.91	<0.001
4. How often did you have nausea?	2.57 ± 0.74	2.53 ± 0.70	0.37	2.77 ± 0.66	2.74 ± 0.69	0.72
5. How often did you have difficulty getting a good night’s sleep because of your heartburn and / or regurgitation?	0.18 ± 0.51	0.32 ± 0.63	<0.001	0.06 ± 0.28	0.29 ± 0.63	<0.001
6. How often did you take additional medication for your heartburn and / or regurgitation, other than what the physician told you to take?	0.23 ± 0.65	0.49 ± 0.84	<0.001	0.08 ± 0.39	0.33 ± 0.77	<0.001

Values are mean ± standard deviation. p-values calculated using Student’s t-test.

CDQ, Carlsson-Dent questionnaire.