Table 2.
Hazard ratios and 95% confidence intervals for the incidence of myocardial infarction, ischemic stroke, and mortality according to smoking behavior change
| Smoking behavior change | Event (n) |
Duration (person-years) |
IR | Hazard ratio (95% confidence interval) | 5-year absolute risk (%) (95% CI) | Risk difference (95% CI) | No. Needed to Treat | ||
|---|---|---|---|---|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | |||||||
| Cardiovascular disease events | |||||||||
| Myocardial infarction | |||||||||
| Quitter | 1,171 | 314,614.7 | 3.7 | 1.00 (0.93–1.07) | 0.81 (0.76–0.87) | 0.80 (0.75–0.86) | 1.54 (1.45, 1.63) | -0.38 (-0.49, -0.27) | 2.6 |
| Reducer I | 573 | 129,894.0 | 4.4 | 1.19 (1.08–1.30) | 1.04 (0.95–1.14) | 1.03 (0.94–1.13) | 1.98 (1.81, 2.14) | 0.06 (-0.12, 0.24) | 16.7 |
| Reducer II | 823 | 226,066.8 | 3.6 | 0.98 (0.91–1.06) | 0.99 (0.92–1.07) | 0.99 (0.92–1.07) | 1.90 (1.77, 2.03) | -0.02 (-0.16, 0.12) | 50 |
| Sustainer | 2,856 | 768,275.4 | 3.7 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 1.92 (1.84, 1.99) | Ref. | Ref. |
| Increaser | 1,091 | 277,276.4 | 3.9 | 1.06 (0.99–1.14) | 1.06 (0.99–1.14) | 1.05 (0.98–1.13) | 2.02 (1.90, 2.14) | 0.10 (-0.03, 0.23) | 10 |
| P value | 0.001 | < 0.001 | < 0.001 | ||||||
| Ischemic stroke | |||||||||
| Quitter | 1,420 | 313,782.0 | 4.5 | 1.00 (0.94–1.06) | 0.82 (0.77–0.87) | 0.80 (0.75–0.85) | 1.90 (1.80, 2.00) | -0.46 (-0.59, -0.33) | 2.2 |
| Reducer I | 699 | 129,406.0 | 5.4 | 1.19 (1.10–1.30) | 1.01 (0.93–1.09) | 1.00 (0.92–1.08) | 2.35 (2.18, 2.52) | -0.01 (-0.20, 0.18) | 100 |
| Reducer II | 948 | 225,652.8 | 4.2 | 0.93 (0.86–1.00) | 0.95 (0.89–1.02) | 0.95 (0.89–1.02) | 2.25 (2.11, 2.39) | -0.11 (-0.27, 0.05) | 9.1 |
| Sustainer | 3,466 | 766,293.8 | 4.5 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 2.36 (2.28, 2.44) | Ref. | Ref. |
| Increaser | 1,304 | 276,608.2 | 4.7 | 1.04 (0.98–1.11) | 1.05 (0.98–1.11) | 1.04 (0.97–1.10) | 2.44 (2.31, 2.57) | 0.08 (-0.07, 0.23) | 12.5 |
| P value | < 0.001 | < 0.001 | < 0.001 | ||||||
| Mortality | |||||||||
| All-cause mortality | |||||||||
| Quitter | 2,881 | 316,956.8 | 9.1 | 1.11 (1.07–1.16) | 0.92 (0.88–0.96) | 0.90 (0.86–0.94) | 3.63 (3.50, 3.77) | -0.40 (-0.56, -0.24) | 2.5 |
| Reducer I | 1,520 | 131,023.4 | 11.6 | 1.43 (1.35–1.51) | 1.15 (1.09–1.22) | 1.14 (1.08–1.21) | 4.55 (4.34, 4.77) | 0.52 (0.29, 0.75) | 2.0 |
| Reducer II | 1,832 | 227,806.9 | 8.0 | 0.99 (0.94–1.04) | 1.02 (0.97–1.07) | 1.02 (0.97–1.07) | 4.10 (3.93, 4.28) | 0.07 (-0.13, 0.27) | 14.3 |
| Sustainer | 6,294 | 774,303.1 | 8.1 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 4.03 (3.94, 4.13) | Ref. | Ref. |
| Increaser | 2,405 | 279,628.3 | 8.6 | 1.06 (1.01–1.11) | 1.07 (1.02–1.12) | 1.06 (1.01–1.11) | 4.24 (4.08, 4.40) | 0.21 (0.02, 0.40) | 4.8 |
| P value | < 0.001 | < 0.001 | < 0.001 | ||||||
| Myocardial infarction mortality | |||||||||
| Quitter | 122 | 316,956.8 | 0.4 | 1.08 (0.87–1.33) | 0.81 (0.65–1.00) | 0.79 (0.64–0.98) | 0.15 (0.12, 0.18) | -0.04 (-0.08, 0.00) | 25 |
| Reducer I | 69 | 131,023.4 | 0.5 | 1.48 (1.13–1.92) | 1.18 (0.90–1.54) | 1.16 (0.89–1.51) | 0.22 (0.17, 0.27) | 0.03 (-0.03, 0.09) | 33.3 |
| Reducer II | 76 | 227,806.9 | 0.3 | 0.94 (0.73–1.21) | 0.94 (0.73–1.21) | 0.94 (0.73–1.21) | 0.18 (0.14, 0.22) | -0.01 (-0.06, 0.04) | 100 |
| Sustainer | 276 | 774,303.1 | 0.4 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 0.19 (0.17, 0.21) | Ref. | Ref. |
| Increaser | 104 | 279,628.3 | 0.4 | 1.05 (0.83–1.31) | 1.06 (0.84–1.33) | 1.05 (0.84–1.32) | 0.20 (0.16, 0.24) | 0.01 (-0.04, 0.06) | 100 |
| P value | 0.046 | 0.099 | 0.084 | ||||||
| Ischemic stroke mortality | |||||||||
| Quitter | 46 | 316,956.8 | 0.1 | 1.04 (0.73–1.46) | 0.69 (0.48–0.98) | 0.67 (0.47–0.95) | 0.05 (0.04, 0.07) | -0.03 (-0.05, -0.01) | 33.3 |
| Reducer I | 25 | 131,023.4 | 0.2 | 1.37 (0.88–2.11) | 0.91 (0.59–1.41) | 0.89 (0.58–1.39) | 0.07 (0.04, 0.10) | -0.01 (-0.04, 0.02) | 100 |
| Reducer II | 31 | 227,806.9 | 0.1 | 0.97 (0.65–1.45) | 0.98 (0.65–1.46) | 0.98 (0.66–1.46) | 0.08 (0.05, 0.11) | 0.00 (-0.03, 0.03) | NA |
| Sustainer | 108 | 774,303.1 | 0.1 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 0.08 (0.06, 0.10) | Ref. | Ref. |
| Increaser | 43 | 279,628.3 | 0.2 | 1.11 (0.78–1.57) | 1.02 (0.71–1.45) | 1.01 (0.71–1.44) | 0.08 (0.06, 0.10) | 0.00 (-0.03, 0.03) | NA |
| P value | 0.684 | 0.291 | 0.222 | ||||||
IR, incidence rate per 1,000 person-years
Model 1: Unadjusted
Mode 2: Adjusted for age, sex, income, area of residence, alcohol consumption, duration of smoking, physical activity, body mass index, and comorbidities (hypertension, dyslipidemia, chronic kidney disease, and chronic obstructive pulmonary disease)
Mode 3: Model 2 + adjusted for fasting glucose, duration of diabetes, and use of insulin