Demographic variable | Total study population | COPD without asthma history | COPD with asthma history | P value* |
Total study population | 3 110 617 (100) | 2 655 739 (85.4) | 454 878 (14.6) | <0.001 |
Mean age in years (SD) | 59.3 (9.2) | 59.2 (9.4) | 59.9 (8.4) | <0.001 |
Male, N (%) | 2 002 486 (64.4) | 1 812 842 (68.3) | 189 644 (41.7) | <0.001 |
Female, N (%) | 1 108 131 (35.6) | 842 897 (31.7) | 265 234 (58.3) | <0.001 |
Non-Hispanic white, N (%) | 2 678 509 (86.1) | 2 322 923 (87.5) | 355 586 (78.2) | <0.001 |
Non-Hispanic black, N (%) | 145 384 (4.7) | 117 210 (4.4) | 28 175 (6.2) | <0.001 |
Hispanic, N (%) | 91 785 (3.0) | 72 687 (2.7) | 19 098 (4.2) | <0.001 |
Other race, N (%) | 194 938 (6.3) | 142 919 (5.4) | 52 019 (11.4) | <0.001 |
40–49 years, N (%) | 426 272 (13.7) | 373 492 (14.1) | 52 780 (11.6) | <0.001 |
50–59 years, N (%) | 1 148 202 (36.9) | 1 043 646 (39.3) | 104 556 (23.0) | <0.001 |
60–69 years, N (%) | 1 092 273 (35.1) | 832 106 (31.3) | 260 167 (57.2) | <0.001 |
70–79 years, N (%) | 443 870 (14.3) | 142 919 (15.3) | 37 376 (8.2) | <0.001 |
Current smoker, N (%) | 833 824 (26.8) | 792 915 (29.9) | 40 909 (9.0) | <0.001 |
Non-smoker, N (%) | 1 201 597 (38.6) | 167 286 (40.2) | 134 310 (29.5) | <0.001 |
Unknown smoking status, N (%) | 1 075 197 (34.6) | 795 538 (30.0) | 279 659 (61.5) | <0.001 |
*P value is comparing the statistical difference between COPD without asthma history group and COPD with asthma history group.