Table 2. Characteristics at recruitment; mean age and prevalence of asthma and respiratory symptoms, smoking habits and socio-economic group in the two cohorts, by sex and among all.
Cohort recruited in 1996 (n=5709) Cohort recruited in 1996 (n=5709) Cohort recruited in 1996 (n=5709) Cohort recruited in 1996 (n=5709) Cohort recruited in 2006 (n=4552) Cohort recruited in 2006 (n=4552) Cohort recruited in 2006 (n=4552) Cohort recruited in 2006 (n=4552)
Women Men All p value1 Women Men All p value1
Age, mean (SD) 44.8 (13.5) 44.4 (13.2) 44.6 (13.3) 0.249 47.7(13.2) 47.6 (13.1) 47.7 (13.1) 0.731
Smoking habits, %
Smoker 27.7 23.9 25.8 <0.001 20.5 14.2 17.5 <0.001
Ex-smoker 19.0 25.0 22.0 23.4 23.9 23.6
Non-smoker 53.3 51.1 52.2 56.1 62.0 58.9
Physician-diagnosed asthma, % 8.6 9.1 8.8 0.461 12.1 9.9 11.1 0.016
Asthma medication, % 11.3 9.6 10.5 0.029 13.5 10.8 12.2 0.005
Recurrent wheeze, % 13.2 12.2 12.7 0.274 11.1 11.7 11.4 0.584
Attacks of shortness of breath, % 15.4 12.5 13.9 0.002 14.1 11.9 14.3 0.026
Allergic rhino-conjunctivitis, % 24.7 22.2 23.4 0.029 27.4 22.8 25.2 <0.001
Family history of asthma, % 24.6 18.6 21.6 <0.001 25.5 19.8 22.8 <0.001
Socioeconomic group, %
Professionals 2.8 7.6 5.3 <0.001 5.5 7.7 6.6 <0.001
Non-manual workers 43.7 27.8 35.6 47.4 30.1 39.1
Manual workers 53.5 64.6 59.1 47.1 62.1 54.3
1 p-value for differences by sex
SD=Standard deviation SD=Standard deviation SD=Standard deviation