Table 2

Number of participants included in analysis stratified by smoking status and pulmonary function impairment, proportion who died during the follow up period, and proportion of deaths with either COPD listed as the underlying cause of death (UCD) or as any cause of death

NDeathsProportion of participants who died (%)Proportion who died with COPD as UCD (%)Proportion who died with any mention of COPD (%)
*Severe COPD = forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.70 and FEV1 <50% predicted; moderate COPD=FEV1/FVC <0.70 and FEV1 ⩾50–<80% predicted; mild COPD=FEV1/FVC <0.70 and FEV1 ⩾80%; symptoms only=presence of respiratory symptoms in the absence of any lung function abnormality; restrictive lung disease=FEV1/FVC ⩾0.70 and FVC <80% predicted.
From the First National Health and Nutrition Examination Survey 1971–5 and follow up to 1992.
Current smokers
    Severe COPD*483777.129.751.4
    Moderate COPD24711647.05.216.4
    Mild COPD2138539.92.47.1
    Respiratory symptoms only4949018.22.28.9
    Restrictive lung disease2248337.14.89.6
    No lung disease109716915.40.62.4
Former smokers
    Severe COPD242187.51957.1
    Moderate COPD813948.15.125.6
    Mild COPD963031.300
    Respiratory symptoms only1754022.905.0
    Restrictive lung disease823846.35.37.9
    No lung disease65212218.70.82.5
Never smokers
    Severe COPD20735.000
    Moderate COPD642539.1012.0
    Mild COPD1304232.300
    Respiratory symptoms only2234319.300
    Restrictive lung disease2057536.604.0
    No lung disease146723916.30.42.1
All subjects
    Severe COPD926570.723.147.7
    Moderate COPD39218045.94.417.8
    Mild COPD43915735.81.33.8
    Respiratory symptoms only89217319.41.25.8
    Restrictive lung disease51119638.43.17.1
    No lung disease321653016.50.62.3