Table 1.

Characteristics : Characteristics of the study population.

	Asthma-allergy day-care centres		Ordinary day-care centres
	n	%	n	%
Age	1000	-	4886	-
1	49	4.9	203	4.2
2	219	21.9	916	18.8
3	221	22.1	976	20.0
4	192	19.2	1017	20.8
5	202	20.2	1168	23.9
6	116	11.6	606	12.4
Boys	545	54.5	2476	50.7
Parts of Sweden
South (Götaland)	416	41.6	2135	43.7
Central (Svealand)	394	39.4	1841	37.7
North (Norrland)	190	19.0	910	18.6