Table 4.
Association between baseline characteristics and incidence of GOLD II (n = 33) in middle-aged smokers (n = 399).
| Characteristic | Odds ratio unadjusted (95% CI) | Odds ratio adjusted (95% CI) | P-value |
|---|---|---|---|
| Age (years) | |||
| 40–44 | 1.0a | 1.8 (1.2–2.6) (per 5 years) | 0.002 |
| 45–49 | 2.1 (0.5–8.7) | ||
| 50–54 | 2.9 (0.8–11.1) | ||
| 55–65 | 6.0 (1.7–21.5) | ||
| Pack yearsb | |||
| <20 | 1.0a | ||
| 20–29 | 2.1 (0.7–6.6) | ||
| ≥30 | 4.7 (1.5–14.9) | ||
| Childhood smoking (absent/present) | 3.5 (1.7–7.5) | 3.3 (1.5–7.3) | 0.002 |
| Cough (absent/present) | 3.1 (1.5–6.5) | 2.2 (1.0–4.8) | 0.05 |
| ≥1 GP contact for LRT | 3.0 (1.4–6.5) | 2.8 (1.3–6.4) | 0.01 |
a
Reference category.
b
Not included in multivariate analysis; Pack years = number of packs smoked per day times number of years smoked. LRT = lower respiratory tract problems in the previous 12 months.