Table 4 Risk of incident myocardial infarction by number of cigarettes per day (cig/day), tar and nicotine yield per cigarette (mg/cig) and tar and nicotine intake per day (mg/day) in women: Hazard ratio (HR) and 95% confidence interval (95% CI)
Smoking habits | Number of participants (N) | Number of events (N) | Age- and survey-adjusted model* HR (95% CI) | MI risk factor-adjusted model+ HR (95% CI) |
|---|---|---|---|---|
Never-smokers++ | 2,613 | 49 | 1.00 | 1.00 |
Ex-smokers | 693 | 15 | 1.95 (1.09-3.48) | 1.93 (1.07-3.47) |
Occasional smokers | 139 | 2 | 1.56 (0.38-6.44) | 1.60 (0.39-6.65) |
Regular smokers | ||||
Number of cigarettes smoked per day | ||||
Light smokers (1 - 19 cig/day) | 480 | 8 | 1.83 (0.86-3.90) | 1.68 (0.79-3.57) |
Heavy smokers (≥ 20 cig/day) | 272 | 6 | 3.76 (1.57-8.97) | 3.86 (1.57-9.50) |
Tar yield per cigarette# | ||||
1 - 12 mg/cig | 328 | 5 | 1.52 (0.60-3.85) | 1.60 (0.63-4.07) |
≥ 13 mg/cig | 424 | 9 | 3.35 (1.62-6.94) | 2.74 (1.31-5.72) |
Nicotine yield per cigarette# | ||||
0.1 - 0.8 mg/cig | 300 | 5 | 1.58 (0.63-3.98) | 1.67 (0.66-4.24) |
≥ 0.8 mg/cig | 452 | 9 | 3.22 (1.55-6.68) | 2.63 (1.26-5.50) |
Tar intake per day# | ||||
1 - 129 mg/day | 324 | 4 | 1.27 (0.46-3.54) | 1.31 (0.47-3.65) |
130 - 259 mg/day | 238 | 5 | 2.72 (1.08-6.88) | 2.30 (0.90-5.87) |
≥ 260 mg/day | 190 | 5 | 5.37 (2.07-13.94) | 4.67 (1.76-12.40) |
Nicotine intake per day# | ||||
1 - 8 mg/day | 368 | 4 | 1.09 (0.39-3.03) | 1.01 (0.36-2.81) |
9 - 16 mg/day | 235 | 6 | 3.84 (1.62-9.12) | 3.88 (1.61-9.35) |
≥ 17 mg/day | 149 | 4 | 5.88 (2.06-16.76) | 5.55 (1.88-16.35) |