Table 4.

Risk of urticaria in relation to demographic characteristics of patients with celiac disease.

Subgroup	Observed events (N)	Expected events (N)*	HR; 95% CI	P-value	Absolute risk/100,000 PYAR	Excess risk/100,000 PYAR	Attributable percentage (%)
Sex
Females	310	201	1.54; 1.36–1.75	<0.001	154	54	35
Males	143	99	1.45; 1.21–1.75	<0.001	118	37	31
Age
0–19 yrs	250	188	1.33; 1.16–1.53	<0.001	172	43	25
20–39 yrs	106	45	2.38; 1.90–2.98	<0.001	179	104	58
40–59 yrs	74	46	1.60; 1.24–2.08	<0.001	100	37	38
≥60	23	22	1.03; 0.66–1.61	0.913	53	2	3
Calendar period
-1989	67	34	1.98; 1.27–3.10	0.037	79	39	49
1990–1999	214	131	1.63; 1.40–1.89	<0.001	134	52	39
2000–2008	172	118	1.46; 1.24–1.72	<0.001	222	70	32

HR, Hazard ratio; CI, Confidence interval; PYAR, Person-years at risk.

Reference is general population comparator cohort.

^*Expected number of events in patients with celiac disease was derived from the observed number of events divided by the HR.