Table 2 Hazard ratios (HRs) of NPC deaths by smoking status in the combined cohort (both sexes)
From: Smoking and nasopharyngeal carcinoma mortality: a cohort study of 101,823 adults in Guangzhou, China
Total person-years of participants | Mortality rate of NPC per 10,000 person-years (95 % CI) | Crude HR (95 % CI) | Model 1 HR (95 % CI) | |
|---|---|---|---|---|
Never smokers | 409,095 | 0.22 (0.11–0.42) | 1.00 | 1.00 |
Smoking status | ||||
Daily smokers | 337,064 | 0.74 (0.50–1.10) | 3.57 (1.66–7.65)** | 2.95 (1.01–8.68)* |
Smoking amount (cigarettes/day) | ||||
1–14 | 162,244 | 0.49 (0.25–0.99) | 2.45 (0.94–6.37) | 1.74 (0.45–6.79) |
15+ | 174,820 | 0.97 (0.60–1.56) | 4.52 (2.01–10.14)** | 4.00 (1.29–12.35)* |
P for trend | <0.001 | 0.012 | ||
Smoking duration (years) | ||||
1–9 | 87,556 | 0.46 (0.17–1.22) | 2.36 (0.72–7.73) | 3.07 (0.69–13.62) |
10+ | 249,508 | 0.84 (0.55–1.29) | 3.94 (1.80–8.60)** | 2.93 (0.97–8.89) |
P for trend | 0.001 | 0.064 | ||
Smoking cumulative consumption (pack-years) | ||||
< 10 | 181,243 | 0.33 (0.15–0.74) | 1.65 (0.59–4.66) | 1.76 (0.45–6.89) |
10+ | 155,821 | 1.22 (0.78–1.91) | 5.52 (2.50–12.20)** | 4.03 (1.29–12.58)* |
P for trend | <0.001 | 0.014 | ||