Table 4.

 Physical exercise and risk of symptomatic gastro-oesophageal reflux

	Number		Univariate		Multivariate*
	Cases	Controls	OR	95% CI	OR	95% CI
Physical exercise† of >30 minutes duration
Never	275	2231	1.0	(reference)	1.0	(reference)
<1/week	116	1020	0.9	(0.7–1.2)	1.0	(0.8–1.2)
1/week	233	3970	0.5	(0.4–0.6)	0.5	(0.4–0.7)
1–3/week	226	3775	0.5	(0.4–0.6)	0.6	(0.5–0.7)
>3/week	116	1432	0.7	(0.5–0.8)	0.7	(0.6–0.9)
p Value for linear trend					<0.0001

*In the multivariate logistic regression model adjustments were made for age, sex, body mass index, tobacco smoking, coffee use, table salt intake, and dietary fibre in bread. Alcohol use, tea drinking, and asthma medication were tested, but omitted from the final model since they did not contribute significantly to the explained variance.

†Data on physical exercise represent exposure previous to reflux outcome assessment.

OR, odds ratio; CI confidence interval.