Associations between parental respiratory disease history, combined life-course factors and symptomatic airflow obstruction (outcome)
| Model 5a | Model 5b | |
| Parental respiratory disease history | 1.29 (0.80–2.09) | 1.34 (0.84–2.14) |
| Childhood passive smoke exposure | 1.18 (0.91–1.52) | |
| Adulthood smoking | ||
| Ever-smoker | 1.71 (1.27–2.31)*** | |
| Persistent smoker | 5.42 (4.19–7.01)*** | |
| SC at 42 years of age | ||
| SC1 | 1.00 (ref) | |
| SC2 | 1.20 (0.87–1.67) | |
| SC3 | 1.29 (0.92–1.81) | |
| SC4 | 1.41 (1.00–1.99) | |
| Asthma | ||
| Childhood | 1.33 (1.02–1.72)* | |
| Adulthood | 6.44 (5.01–8.27)*** | |
| Pneumonia (childhood) | 1.33 (0.82–2.16) | 1.13 (0.71–1.79) |
| Occupational exposure | 1.00 (0.76–1.30) | 1.09 (0.84–1.40) |
| Cumulative SC | 1.03 (0.98–1.08) | |
| Cumulative smoking exposure | ||
| 0 (never) | 1.00 (ref.) | |
| 1 | 0.98 (0.63–1.52) | |
| 2 | 1.07 (0.68–1.67) | |
| 3 | 2.38 (1.55–3.64)*** | |
| 4 (persistent) | 5.39 (3.51–8.27)*** | |
| Cumulative asthma | ||
| 0 (never) | 1.00 (ref.) | |
| 1 | 2.51 (1.95–3.23)*** | |
| 2 (persistent) | 8.13 (5.98–11.07)*** | |
| Total effects estimate (se) | 0.614 (0.258)** | 0.603 (0.250)** |
| Total indirect effects estimate (se) | 0.359 (0.082)*** | 0.308 (0.075)*** |
| Model fit | ||
| AIC | 57 978.796 | 68 436.130 |
| BIC | 58 295.306 | 68 718.968 |
Data are presented as OR (95% CI) unless otherwise stated. All models were adjusted for sex and recent chest infection (past 3 weeks prior to when spirometry was performed at age 45 years). SC: social class (SC1: professional/managerial; SC2: unskilled nonmanual; SC3: skilled manual; SC4: unskilled manual); AIC: Akaike information criterion; BIC: Bayesian information criterion. *: p<0.05; **: p<0.005; ***: p<0.001.