Table 1.
Numbers of Reported Incident Myocardial Infarctions and Fatal Coronary Heart Disease (CHD) Deaths for the Agricultural Health Study (AHS) and CHD Deaths for the Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study, Person-Years (P-yrs) At Risk, Relative Risks (RRs) With 95% Confidence Intervals (CI) for Pack-Years of Cigarette Smoking and Cigarettes Smoked per day, Individually and Jointly
| Eventsa | P-yrs | RRb | 95% CI | RRb | 95% CI | RRb,c | 95% CI | |
|---|---|---|---|---|---|---|---|---|
| AHS cohort | ||||||||
| Never-smoker | 1941 | 885273.0 | 1 | 1 | 1 | |||
| Pack-years of smoking | ||||||||
| 1–19 | 1009 | 311082.0 | 1.26 | (1.17,1.36) | 1.25 | (1.10,1.41) | ||
| 20–29 | 338 | 76202.8 | 1.59 | (1.41,1.79) | 1.61 | (1.34,1.94) | ||
| 30–39 | 303 | 55397.2 | 1.67 | (1.46,1.92) | 1.77 | (1.43,2.18) | ||
| 40–49 | 247 | 36000.6 | 1.98 | (1.71,2.30) | 2.18 | (1.79,2.64) | ||
| 50–59 | 154 | 20566.6 | 2.18 | (1.752.71) | 2.42 | (1.81,3.25) | ||
| ≥60 | 404 | 41453.8 | 2.26 | (1.96,2.60) | 2.75 | (2.22,3.41) | ||
| pd | <.01 | <.01 | ||||||
| Cigarettes/day | ||||||||
| 1–9 | 314 | 94722.4 | 1.24 | (1.10,1.42) | 1 | |||
| 10–19 | 455 | 128144.0 | 1.53 | (1.27,1.84) | 1.09 | (0.88,1.33) | ||
| 20–29 | 918 | 188401.0 | 1.55 | (1.37,1.76) | 0.95 | (0.81,1.11) | ||
| 30–39 | 302 | 54168.9 | 1.80 | (1.58,2.04) | 0.87 | (0.72,1.06) | ||
| ≥40 | 466 | 75266.9 | 1.80 | (1.59,2.04) | 0.78 | (0.63,0.97) | ||
| pd | <.01 | .02 | ||||||
| ATBC cohort | ||||||||
| Never-smoker | 1 | 1 | 1 | |||||
| Pack-years of smoking | ||||||||
| 1–19 | 568 | 65513.1 | 1.54 | (1.42,1.68) | 1.54 | (1.41,1.68) | ||
| 20–29 | 799 | 69219.1 | 2.01 | (1.87,2.15) | 1.99 | (1.78,2.23) | ||
| 30–39 | 991 | 91442.3 | 2.10 | (1.97,2.24) | 2.10 | (1.84,2.40) | ||
| 40–49 | 1143 | 99164.1 | 2.11 | (2.00,2.24) | 2.17 | (1.90,2.48) | ||
| 50–59 | 996 | 70317.6 | 2.34 | (2.20,2.49) | 2.46 | (2.14,2.83) | ||
| ≥60 | 1482 | 90987.0 | 2.63 | (2.50,2.77) | 2.85 | (2.46,3.31) | ||
| pd | <.01 | <.01 | ||||||
| Cigarettes/day | ||||||||
| 1–9 | 619 | 54339.7 | 1.67 | (1.54,1.81) | 1 | |||
| 10–19 | 2499 | 190647.0 | 2.14 | (2.06,2.22) | 1.02 | (0.91,1.15) | ||
| 20–29 | 2193 | 185687.0 | 2.28 | (2.18,2.37) | 0.93 | (0.81,1.06) | ||
| 30–39 | 488 | 42109.4 | 2.43 | (2.23,2.66) | 0.87 | (0.74,1.03) | ||
| ≥40 | 180 | 13860.1 | 2.87 | (2.48,3.32) | 1.01 | (0.82,1.24) | ||
| pd | .01 | .01 | ||||||
aNumbers for events reflect smoking status at cohort exit and for AHS categories at one imputation.
bFor the AHS cohort, RRs in relation to never-smokers adjusted for age, calendar year, sex, state, body mass index, physician diagnosed hypertension, diabetes and regular use of alcohol, with entries based on M = 5 imputations. For the ATBC cohort, RRs in relation to Finnish mortality rates adjusted to represent never-smokers.
cModel includes main effects for both pack-years and cigarettes/day, with the RR for 1–9 cigarettes/day set to one for identifiability.
d p value for test of no linear trend.