Table 3

Incidence of asthma in women and men who reported they never had asthma at baseline

Outcome at follow-up	Number of incident cases		Person-years		Incidence per 1000 person-years (95% CI)		HR^* (95% CI)
Outcome at follow-up	Women	Men	Women	Men	Women	Men	Women/men
Asthma	152	82	36 733	34 351	4.14 (3.48 to 4.80)	2.39 (1.87 to 2.90)	1.74 (1.33 to 2.27)
Asthma by age at baseline:
20–27 years	34	20	9118	8538	3.73 (2.48 to 4.98)	2.34 (1.32 to 3.37)	1.58 (0.91 to 2.75)
28–35 years	52	17	11 761	10 709	4.42 (3.22 to 5.62)	1.59 (0.83 to 2.34)	2.76 (1.60 to 4.77)
≥36 years	66	45	15 854	15 104	4.16 (3.16 to 5.17)	2.98 (2.11 to 3.85)	1.40 (0.96 to 2.04)
Allergic asthma	44	39	27 403	27 189	1.61 (1.13 to 2.08)	1.43 (0.98 to 1.88)	1.12 (0.73 to 1.72)
Non-allergic asthma	81	23	27 403	27 189	2.96 (2.31 to 3.60)	0.85 (0.50 to 1.19)	3.51 (2.21 to 5.58)

↵* Cox regression analysis (based on age at asthma onset) for incidence of doctor-diagnosed asthma in subjects who reported they never had asthma at baseline. Excludes incident cases with age at asthma onset missing or age at onset ≥5 years before baseline (see methods).