Table 2.
Hazard ratios (95% CI) for lung cancer risk associated with smoking status, UK Biobank, 2006–2016
| Smoking status | No. of cases | HR (95% CI)a |
|---|---|---|
| Never smokers | 179 | 1 (reference) |
| Heavy smokersb | 654 | 19.9 (16.8–23.6) |
| Current smokers | 365 | 27.6 (23.0–33.1) |
| Former smokers, quit-time ≤ 15 years | 289 | 14.8 (12.2–17.8) |
| Other current smokers | ||
| 20–29 pack-years | 106 | 20.7 (16.3–26.4) |
| <20 pack-years | 58 | 9.83 (7.30–13.2) |
| Missing pack-year information | 73 | 8.88 (6.75–11.7) |
| Other former smokers | ||
| ≥30 pack-years, quit-time >15 years | 63 | 6.29 (4.70–8.42) |
| 20–29 pack-years, quit-time ≤ 15 years | 45 | 7.45 (5.37–10.3) |
| 20–29 pack-years, quit-time > 15 years | 50 | 4.23 (3.08–5.79) |
| <20 pack-years, quit-time ≤ 15 years | 18 | 3.40 (2.10–5.53) |
| <20 pack-years, quit-time > 15 years | 80 | 1.92 (1.47–2.50) |
| Missing pack-years information | 123 | 2.38 (1.89–3.00) |
aHRs were adjusted for sex and education.
bIndividuals who had a smoking history of ≥30 pack-years and currently smoked or had quit within the past 15 years.