Association between passive smoking, COPD, respiratory symptoms and clinically significant COPD among never-smoking participants of the Health Survey for England (data including participants reporting presence of asthma)
| COPD* | Respiratory symptoms† | Clinically significant COPD‡ | |
| Adjusted OR (95% CI)§ | Adjusted OR (95% CI)§ | Adjusted OR (95% CI)§ | |
| n | 8849 | 6004 | 6004 |
| Age (years) | |||
| 40–49 | 1.00 | 1.00 | 1.00 |
| 50–59 | 1.06 (0.82 to 1.35) | 1.33 (1.14 to 1.56) | 1.17 (0.75 to 1.82) |
| 60–69 | 1.30 (1.02 to 1.67) | 2.04 (1.74 to 2.39) | 2.13 (1.41 to 3.22) |
| 70–79 | 1.88 (1.45 to 2.46) | 2.93 (2.45 to 3.50) | 3.59 (2.35 to 5.49) |
| 80+ | 2.98 (2.16 to 4.13) | 3.90 (3.06 to 4.96) | 5.54 (3.31 to 9.28) |
| Sex | |||
| Male | 1.00 | 1.00 | 1.00 |
| Female | 0.93 (0.78 to 1.12) | 1.38 (1.22 to 1.56) | 0.96 (0.71 to 1.28) |
| Asthma | |||
| No | 1.00 | 1.00 | 1.00 |
| Yes | 4.51 (3.70 to 5.50) | 7.17 (5.85 to 8.80) | 10.20 (7.65 to 13.59) |
| Year | |||
| 1995 | 1.00 | 1.00 | 1.00 |
| 1996 | 0.81 (0.66 to 0.98) | 0.99 (0.88 to 1.10) | 0.71 (0.54 to 0.94) |
| 2001 | 0.64 (0.52 to 0.80) | – | – |
| Passive smoking exposure (h/week) | |||
| 0 | 1.00 | 1.00 | 1.00 |
| 1–19 | 1.16 (0.97 to 1.40) | 1.19 (1.05 to 1.34) | 1.19 (0.88 to 1.61) |
| 20+ | 1.25 (0.90 to 1.72) | 1.70 (1.39 to 2.08) | 1.47 (0.89 to 2.43) |
↵* Lower limit of normal (LLN) criteria24 25: participants with FEV1/FVC values >1.645 SD below the mean reference value.
↵† Respiratory symptoms: any of dyspnoea, wheeze, chronic cough or phlegm.
↵‡ Lower limit of normal (LLN) criteria24 25: participants with FEV1/FVC values >1.645 SD below the mean reference value plus respiratory symptoms.
↵§ Adjusted for age, sex, passive smoking exposure, year of study and history of asthma.
COPD, chronic obstructive pulmonary disease.