Multiple linear regression analyses with percentage predicted FEV1 and FEV1/FVC as dependent variables
| 1976–8 (n=1034) | 1991–4 (n=1104) | |
| FEV1 (% predicted) | ||
| Smoking | –2.3 (–4.3 to –0.3) | –2.7 (–4.2 to –1.2) |
| Asthma | –2.4 (–10.4 to 5.6) | –10.0 (–13.5 to –6.4) |
| FEV1/FVC (% predicted) | ||
| Smoking | –1.1 (–2.5 to 0.2) | –1.9 (–2.8 to –1.0) |
| Asthma | –1.8 (–7.2 to 3.5) | –7.8 (–9.9 to –5.6) |
Figures in the table are regression coefficients in units of the dependent variable for smokers relative to non-smokers and asthmatics relative to non-asthmatics, respectively. In brackets are shown the 95 % confidence intervals of the regression coefficients.