Mutually adjusted relative risk ratios (RRRs)* (with 95% confidence intervals) for the association between the GOLD severity stages and active/passive smoking exposure, respiratory infections before the age of 5 years, occupational exposure to vapours, gas, dust or fumes in a lifetime, socioeconomic class, and sex
| RRR (95% CI) | Comparison between RRRs† | ||
|---|---|---|---|
| Stage 0 | Stages I+ | ||
| *Also adjusted for the effect of the ECRHS countries (reference population: subjects with neither chronic symptoms nor airflow obstruction). | |||
| †p values obtained by the Wald test. | |||
| ‡ETS+/−: presence/absence of exposure to environmental tobacco smoke. | |||
| §p value for comparison between the adjusted RRRs for past smoking. | |||
| ¶p value for comparison between the adjusted RRRs for exposure to environmental tobacco smoke. | |||
| **Cigars, cigarillos. or pipe tobacco. | |||
| ††p value for comparison between the adjusted RRRs for current smoking. | |||
| Active/passive smoking exposure (v non-smoker and ETS−)‡ | |||
| Past smoker and ETS− | 1.05 (0.86 to 1.27) | 1.39 (1.04 to 1.86) | 0.10§ |
| Non-smoker and ETS+ | 1.18 (0.92 to 1.51) | 1.16 (0.75 to 1.80) | } 0.77¶ |
| Past smoker and ETS+ | 1.15 (0.84 to 1.56) | 1.41 (0.86 to 2.29) | |
| Smoker (<15 pack years) | 2.38 (2.05 to 2.77) | 1.22 (0.90 to 1.65) | } <0.001†† |
| Smoker (⩾15 pack years) | 4.15 (3.55 to 4.84) | 4.09 (3.17 to 5.26) | |
| Smoker (other tobaccos)** | 1.45 (0.91 to 2.31) | 3.25 (1.91 to 5.53) | |
| Respiratory infections (present v absent) | 1.47 (1.25 to 1.74) | 1.62 (1.24 to 2.12) | 0.53 |
| Occupational exposure (present v absent) | 1.47 (1.31 to 1.65) | 1.08 (0.88 to 1.31) | 0.006 |
| Socioeconomic class (low v high) | 1.22 (1.07 to 1.40) | 1.34 (1.05 to 1.71) | 0.51 |
| Sex (female v male) | 1.00 (0.89 to 1.12) | 0.55 (0.45 to 0.67) | <0.001 |