Decrements of forced expiratory volume in one second(FEV1) in male offspring who smoke associated with various definitions of chronic obstructive pulmonary disease (COPD) death in a father compared with such offspring with no parental history of COPD death
| Family history | Effect on FEV1 mL | p-value |
| COPD anywhere on the death certificate | −235 (−64– −407) | 0.007 |
| COPD as first cause of death | −255 (+36– −546) | 0.086 |
| COPD anywhere on death certificate and death at <70 yrs | −319 (−2– −636) | 0.049 |
| COPD as first cause of death at <70 yrs | −478 (−12– −943) | 0.044 |
Values given in parentheses are 95% confidence intervals. All values are adjusted for age, height, maternal smoking, pack-yrs of personal smoking, parental social class, parental housing tenure, personal social class and personal housing tenure.