Correlation coefficients for key variables (95% confidence intervals) (upper diagonal = United States; lower diagonal = Canada)
| Standard tar | Standard nicotine | Standard CO | Percent ventilation | Total nicotine | Percent nicotine | Filter weight | |
|---|---|---|---|---|---|---|---|
| Standard tar | 1.00 | 0.98 (0.96 to 0.99) | 0.97 (0.93 to 0.99) | −0.92 (−0.96 to −0.84) | 0.44 (0.10 to 0.68) | −0.07 (−0.41 to 0.29) | −0.79 (−0.89 to −0.61) |
| Standard nicotine | 0.97 (0.93 to 0.99) | 1.00 | 0.95 (0.90 to 0.98) | −0.90 (−0.95 to −0.81) | 0.51 (0.20 to 0.73) | −0.01 (−0.35 to 0.34) | −0.77 (−0.88 to −0.58) |
| Standard CO | 0.99 (0.98 to 0.99) | 0.95 (0.89 to 0.98) | 1.00 | −0.95 (−0.98 to −0.90) | 0.32 (−0.05 to 0.61) | −0.16 (−0.49 to 0.21) | −0.73 (−0.87 to −0.51) |
| Percent ventilation | −0.90 (−0.96 to −0.78) | −0.84 (−0.93 to −0.65) | −0.92 (−0.97 to 0.83) | 1.00 | −0.33 (−0.61 to 0.03) | 0.11 (−0.25 to 0.44) | 0.66 (0.40 to 0.82) |
| Total nicotine | 0.00 (−0.41 to 0.41) | 0.08 (−0.34 to 0.48) | 0.01 (−0.41 to 0.42) | 0.06 (−0.36 to 0.46) | 1.00 | 0.70 (0.47 to 0.84) | −0.23 (−0.53 to 0.13) |
| Percent nicotine | −0.27 (−0.61 to 0.16) | −0.17 (−0.55 to 0.26) | −0.27 (−0.61 to 0.16) | 0.28 (−0.15 to 0.62) | 0.94 (0.85 to 0.97) | 1.0 | 0.26 (−0.10 to 0.56) |
| Filter weight | −0.46 (−0.74 to −0.06) | −0.45 (−0.73 to 0.05) | −0.43 (−0.72 to 0.02) | 0.30 (−0.13 to 0.63) | 0.46 (0.05 to 0.73) | 0.52 (0.14 to 0.77) | 1.0 |