Table 3.
Individual and joint effects of smoking and drinking on NPC adjusted for age, sex, education, cohort & occupational status
| Category | Total person-years of participants | Mortality rate of NPC per 10,000 person-years (95 % CI) | No of deaths | Model 2 HR (95 % CI) |
|---|---|---|---|---|
| Smoking and drinking status | ||||
| Never smoker and never drinker | 390,148 | 0.21 (0.10–0.41) | 8 | 1.00 |
| Never smoker and daily drinker | 6265 | 1.60 (0.22–11.33) | 1 | 4.19 (0.47–37.22) |
| Daily smoker and never drinker | 240,998 | 0.50 (0.28–0.88) | 12 | 2.95 (1.01–8.68)* |
| Daily smoker and daily drinker | 56,597 | 1.06 (0.48–2.36) | 6 | 3.38 (0.95–11.97) |
| Smoking amount and drinking status (cigarettes/day)a | ||||
| Never smoker and never drinker | 390,148 | 0.21 (0.10–0.41) | 8 | 1.00 |
| Never smoker and daily drinker | 6265 | 1.60 (0.22–11.33) | 1 | 4.49 (0.51–39.90) |
| Level 1 smoking amount and never drinker | 125,001 | 0.32 (0.12–0.85) | 4 | 2.15 (0.56–8.18) |
| Level 1 smoking amount and daily drinker | 21,113 | / | 0 | / |
| Level 2 smoking amount and never drinker | 115,997 | 0.53 (0.28–1.02) | 8 | 3.55 (1.12–11.31)* |
| Level 2 smoking amount and daily drinker | 35,485 | 1.28 (0.58–2.86) | 6 | 4.86 (1.34–17.61)* |
| Smoking duration and drinking status (years)b | ||||
| Never smoker and never drinker | 390,148 | 0.21 (0.10–0.41) | 8 | 1.00 |
| Never smoker and daily drinker | 6265 | 1.60 (0.22–11.33) | 1 | 4.21 (0.47–37.41) |
| Level 1 smoking duration and never drinker | 71,958 | 0.42 (0.13–1.29) | 3 | 3.52 (0.81–15.34) |
| Level 1 smoking duration and daily drinker | 9877 | / | 0 | / |
| Level 2 smoking duration and never drinker | 169,040 | 0.53 (0.28–1.02) | 9 | 2.67 (0.87–8.23) |
| Level 2 smoking duration and daily drinker | 46,720 | 1.28 (0.58–2.86) | 6 | 3.61 (1.01–12.93)* |
| Smoking cumulative consumption and drinking status (pack-years)c | ||||
| Never smoker and never drinker | 390,148 | 0.21 (0.10–0.41) | 8 | 1.00 |
| Never smoker and daily drinker | 6265 | 1.60 (0.22–11.33) | 1 | 4.65 (0.52–41.41) |
| Level 1 smoking cumulative consumption and never drinker | 143,711 | 0.28 (0.10–0.74) | 4 | 2.10 (0.55–8.11) |
| Level 1 smoking cumulative consumption and daily drinker | 22,306 | / | 0 | / |
| Level 2 smoking cumulative consumption and never drinker | 97,286 | 0.82 (0.41–1.64) | 8 | 3.69 (1.15–11.82)* |
| Level 2 smoking cumulative consumption and daily drinker | 34,291 | 1.75 (0.79–3.89) | 6 | 4.77 (1.30–17.50)* |
Model 2 – adjusted for age, sex, education, cohort & occupational status with smoking and alcohol interaction terms
*p < 0.05
aLevel 1: smoked 1–14 cigarettes per day, Level 2: smoked more than 15 cigarettes per day
bLevel 1: 1–9 years of smoking duration, Level 2: more than 10 years of smoking duration
cLevel 1: less than 10 pack-years of smoking cumulative consumption, Level 2: more than 10 pack-years of smoking cumulative consumption