Perceived food intolerance and irritable bowel syndrome in a population 3 years after a giardiasis-outbreak: a historical cohort study

Table 2 Perceived food intolerance in Giardia exposed (n = 764) and a control group (n = 1100) 3 years after an outbreak of giardiasis in Bergen, Norway, 2004

		Perceived food intolerance^a
Group		No		Yes^b						Severity of perceived food intolerance
						Unadjusted		Adjusted^c		Light		Moderate		Severe		P
	N	n	%	n	%	OR	95 % CI	OR	95 % CI	n	%	n	%	n	%
Exposure status
Exposed	764	276	36.1	488	63.9	1.94	1.61 to 2.35	2.00	1.65 to 2.42	238	31.2	168	22.0	82	10.7	<0.001
Control	1100	576	52.4	524	47.6	1.94	1.61 to 2.35	2.00	1.65 to 2.42	368	33.5	116	10.5	40	3.6	<0.001
IBS status
IBS	501	98	19.6	403	80.4	5.16	4.04 to 6.60	5.03	3.93 to 6.45	147	29.3	167	33.3	89	17.8	<0.001
No-IBS	1344	748	55.7	596	44.3	5.16	4.04 to 6.60	5.03	3.93 to 6.45	451	33.6	113	8.4	32	2.4	<0.001
Within IBS
Exposed	348	65	18.7	283	81.3	1.20^d	0.75 to 1.92	1.25	0.78 to 2.01	105	30.2	111	31.9	67	19.3	0.418
Control	153	33	21.6	120	78.4	1.20^d	0.75 to 1.92	1.25	0.78 to 2.01	42	27.5	56	36.6	22	14.4	0.418
Within No-IBS
Exposed	406	207	51.0	199	49.0	1.31^d	1.04 to 1.66	1.36	1.07 to 1.72	130	32.0	55	13.5	14	3.4	<0.001
Control	938	541	57.7	397	42.3	1.31^d	1.04 to 1.66	1.36	1.07 to 1.72	321	34.2	58	6.2	18	1.9	<0.001

Abbreviations: IBS irritable bowel syndrome, P p-value from Pearson’s chi square test (exact), CI confidence interval, OR odds ratio
^aThe question pertaining to these categories was: “Do certain types of food give you abdominal symptoms?” with four alternatives: none, light, moderate, severe
^bFour level response variable dichotomized to no (none) vs. yes (light, moderate or severe)
^cAdjusted for gender and age
^dThe Breslis reasonably high, howeverow-Day test was non-significant

ISSN: 1471-230X