Table 2.

Correlation of risk of developing symptoms of acute gastroenteritis with number of glasses of drinking water from Lilla Edet water treatment plant consumed per day

Exposure	Cases, n (%)	Controls, n (%)	Total (N)	OR	95% CI	P
0 glass/no answer	106 (9)	1111 (91)	1217	1
1 glass	21 (20)	82 (80)	103	2·68	1·60–4·51	<0·001
2 glasses	36 (23)	121 (77)	157	3·12	2·04–4·76	<0·001
3–5 glasses	99 (32)	206 (68)	305	5·04	3·69–6·88	<0·001
6–10 glasses	89 (48)	98 (52)	187	9·52	6·71–13·35	<0·001
>10 glasses	28 (46)	33 (54)	61	8·89	5·17–15·28	<0·001

OR, Odds ratio; CI, confidence interval.