| Practice Volume | <50 (reference) | 2994 | . | <0.0001 |
| 50 - 99 | 4007 | 0.87 (0.77 - 0.99) | ||
| 100 - 149 | 824 | 1.09 (0.89 - 1.33) | ||
| 150+ | 598 | 0.50 (0.39 - 0.63) | ||
| Smoking Status | Current (reference) | 1631 | . | <0.0001 |
| Former | 5439 | 1.29 (1.13 - 1.46) | ||
| Never | 1353 | 1.63 (1.38 - 1.91) | ||
| Gender | Male (reference) | 4402 | . | 0.0522 |
| Female | 4021 | 1.10 (0.99 - 1.21) | ||
| Year of Diagnosis | 2012 (reference) | 952 | . | <0.0001 |
| 2013 | 1403 | 1.26 (1.03 - 1.53) | ||
| 2014 | 1479 | 1.80 (1.48 - 2.18) | ||
| 2015 | 1579 | 2.50 (2.07 - 3.02) | ||
| 2016 | 1663 | 3.27 (2.71 - 3.95) | ||
| 2017 | 1347 | 4.22 (3.47 - 5.13) |