Table. 1—

1 Cases examined, included and not included in the study, and reasons for exclusion by sex and age

	Sex		Age yrs				Total
	Male	Female	19–29	30–39	40–49	50–60
Examined cases n	153	266	128	123	109	59	419
Included cases n	107	202	89	94	81	45	309
Excluded cases n	46	64	39	29	28	14	110
Reason for exclusion n
Probable asthma, but inclusion criteria not fulfilled	9	26	16	7	10	2	35
Asthma, but debut >12 months ago	17	18	13	11	6	5	35
Chronic bronchitis or COPD	2	3	0	1	2	2	5
Not obstructive lung disease	16	13	7	9	9	4	29
Asthma, but could not or did not want to participate	2	4	3	1	1	1	6