Table 2.

Results of a Poisson regression analysis of 121,051 patients’ data, collected between 1992 and 2006 by the IVDK network

Variable	%	PR	95% CI
Sex: female	63.05	1.11	1.01–1.21
Atopic eczema (past or current)	18.30	1.16	1.05–1.28
Age group
≤ 32	25.95	1.00	(reference)
33–46	23.19	1.48	1.32–1.66
47–60	25.25	1.81	1.62–2.03
≥ 61	25.60	1.87	1.63–2.14
Study period
1992–1996	31.62	1.00	(reference)
1997–2001	34.17	0.81	0.74–0.89
2002–2006	34.22	0.77	0.70–0.85
Anatomical site
Trunk	3.61	1.00	(reference)
Axillae	0.78	0.43	0.15–0.99
Arm(s)	3.83	1.55	1.11–2.19
Hand(s)	29.04	3.15	2.41–4.21
Anogenital	2.56	0.62	0.36–1.02
Leg(s)	10.53	1.54	1.16–2.09
Foot/feet	3.49	1.53	1.09–2.17
Neck	1.32	0.84	0.47–1.42
Face	15.73	1.02	0.76–1.39
Scalp	3.00	0.69	0.43–1.07
Flexures	0.51	1.21	0.53–2.41
Generalised	8.40	1.23	0.90–1.70
“Other” site	8.66	0.71	0.50–1.01
Number of additional contact allergies
None	54.38	1.00	(reference)
1	23.84	2.28	2.05–2.53
2	11.87	3.60	3.22–4.02
3	5.56	4.39	3.85–5.01
4 or more	4.34	6.98	6.17–7.89

Risk quantified with the prevalence ratio (PR), accompanied by a 95% confidence interval (CI)–first part: non-occupational factors