Table 4.
Exhaled CO Variable | No. Events/Individuals at Risk* | Model 1 HR (95% CI) | P value | Model 2 HR (95% CI) | P value | Model 3 HR (95% CI) | P value |
---|---|---|---|---|---|---|---|
Log CO† | 416/4139 | 1.72 (1.50–1.98) | <0.0001 | 1.62 (1.40–1.88) | <0.0001 | 1.46 (1.18–1.82) | 0.0006 |
1st quartile‡ | 92/836 | Referent | … | Referent | … | Referent | … |
2nd quartile | 80/922 | 0.76 (0.56–1.02) | 0.070 | 0.75 (0.55–1.01) | 0.057 | 0.74 (0.55–1.00) | 0.052 |
3rd quartile | 109/991 | 1.12 (0.84–1.48) | 0.43 | 1.05 (0.78–1.39) | 0.76 | 1.03 (0.77–1.37) | 0.84 |
4th quartile | 135/1390 | 2.19 (1.66–2.89) | <0.0001 | 1.94 (1.45–2.58) | <0.0001 | 1.66 (1.14–2.40) | 0.008 |
CO, carbon monoxide; HR, hazards ratio; CI, confidence interval.
Model 1 is adjusted for age and sex. Model 2 is adjusted for age, sex, systolic and diastolic blood pressure, total/HDL cholesterol, diabetes, and examination cycle. Model 3 is adjusted for age, sex, BMI, systolic and diastolic blood pressure, total/HDL cholesterol, diabetes, examination cycle, and smoking status.
Number of attendees at risk: 14943 in the total sample; 3674, 4037, 3871, and 3361 across increasing quartiles of exhaled CO, respectively.
Risk estimates correspond to 1 unit change in log CO (in ppm).
Exhaled CO quartiles are defined as 0 to <4, ≥4–<5, ≥5–<6, and ≥6 ppm, respectively.