TABLE 1.
Baseline Demographics, Clinical Characteristics, and Health Care Costs of Study Cohorts Before and After Propensity Score Matching
| Before Matching | P Valuea | After Matching | P Valuea | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Apixaban n = 8,250 | Warfarin n= 14,051 | Apixaban n = 7,107 | Warfarin n= 7,107 | |||||||
| Demographics | ||||||||||
| Age | ||||||||||
| Mean (SD) | 78.0 (9.0) | 78.2 (9.0) | 0.03 | 78.2 (9.1) | 78.1 (8.8) | 0.54 | ||||
| Median | 76 | 77 | 77 | 77 | ||||||
| n | % | n | % | n | % | n | % | |||
| Gender | ||||||||||
| Male | 4,249 | 51.5 | 7,757 | 55.2 | < 0.001 | 3,740 | 52.6 | 3,688 | 51.9 | 0.38 |
| U.S. geographic region | < 0.001 | 0.82 | ||||||||
| South | 5,707 | 69.2 | 7,807 | 55.6 | 4,675 | 65.8 | 4,717 | 66.4 | ||
| Midwest | 1,582 | 19.2 | 4,168 | 29.7 | 1,514 | 21.3 | 1,504 | 21.2 | ||
| West | 775 | 9.4 | 1,640 | 11.7 | 737 | 10.4 | 705 | 9.9 | ||
| Northeast | 186 | 2.3 | 436 | 3.1 | 181 | 2.6 | 181 | 2.6 | ||
| Race/ethnicity | < 0.001 | 0.85 | ||||||||
| White | 7,385 | 89.5 | 12,507 | 89.0 | 6,373 | 89.7 | 6,371 | 89.6 | ||
| Black | 481 | 5.8 | 977 | 7.0 | 440 | 6.2 | 436 | 6.1 | ||
| Other | 192 | 2.3 | 329 | 2.3 | 167 | 2.4 | 160 | 2.3 | ||
| Unknown | 192 | 2.3 | 238 | 1.7 | 127 | 1.8 | 140 | 2.0 | ||
| Clinical characteristics | ||||||||||
| Charlson Comorbidity Index score | ||||||||||
| Mean (SD) | 3.0 (2.5) | 3.4 (2.6) | < 0.001 | 3.0 (2.4) | 3.0 (2.4) | 0.97 | ||||
| Median | 3 | 3 | 3 | 3 | ||||||
| CHADS2 score | ||||||||||
| Mean (SD) | 2.7 (1.4) | 2.9 (1.4) | < 0.001 | 2.7 (1.4) | 2.7 (1.3) | 0.37 | ||||
| Median | 3 | 3 | 3 | 3 | ||||||
| CHA2DS2-Vasc score | ||||||||||
| Mean (SD) | 4.6 (1.6) | 4.7 (1.6) | < 0.001 | 4.6 (1.6) | 4.6 (1.6) | 0.66 | ||||
| Median | 4 | 5 | 4 | 4 | ||||||
| HAS-BLED score | ||||||||||
| Mean (SD) | 3.1 (1.2) | 3.2 (1.2) | < 0.001 | 3.0 (1.1) | 3.1 (1.1) | 0.22 | ||||
| Median | 3 | 3 | 3 | 3 | ||||||
| Baseline conditions | n | % | n | % | n | % | n | % | ||
| Previous bleeding | 1,561 | 18.9 | 3,375 | 24.0 | < 0.001 | 1,339 | 18.8 | 1,350 | 19.0 | 0.81 |
| Previous stroke | 970 | 11.8 | 2,216 | 15.8 | < 0.001 | 842 | 11.9 | 834 | 11.7 | 0.84 |
| Thrombocytopenia | 316 | 3.8 | 691 | 4.9 | < 0.001 | 252 | 3.6 | 274 | 3.9 | 0.33 |
| CHF | 2,580 | 31.3 | 5,045 | 35.9 | < 0.001 | 2,224 | 31.3 | 2,234 | 31.4 | 0.86 |
| Diabetes | 3,165 | 38.4 | 6,204 | 44.2 | < 0.001 | 2,775 | 39.1 | 2,717 | 38.2 | 0.32 |
| Hypertension | 7,543 | 91.4 | 12,841 | 91.4 | 0.91 | 6,469 | 91.0 | 6,513 | 91.6 | 0.19 |
| Renal disease | 2,580 | 31.3 | 5,135 | 36.6 | < 0.001 | 2,231 | 31.4 | 2,227 | 31.3 | 0.94 |
| MI | 1,362 | 16.5 | 2,597 | 18.5 | < 0.001 | 1,141 | 16.1 | 1,115 | 15.7 | 0.55 |
| Dyspepsia | 1,771 | 21.5 | 3,022 | 21.5 | 0.94 | 1,449 | 20.4 | 1,436 | 20.2 | 0.79 |
| PVD | 4,724 | 57.3 | 8,494 | 60.5 | < 0.001 | 4,076 | 57.4 | 4,010 | 56.4 | 0.26 |
| TIA | 590 | 7.2 | 1,115 | 7.9 | 0.03 | 495 | 7.0 | 504 | 7.1 | 0.77 |
| CAD | 4,075 | 49.4 | 7,167 | 51.0 | 0.02 | 3,485 | 49.0 | 3,435 | 48.3 | 0.40 |
| Baseline medications | n | % | n | % | n | % | n | % | ||
| ACE inhibitor | 3,589 | 43.5 | 6,479 | 46.1 | < 0.001 | 3,130 | 44.0 | 3,136 | 44.1 | 0.92 |
| Amiodarone | 1,115 | 13.5 | 1,638 | 11.7 | < 0.001 | 839 | 11.8 | 819 | 11.5 | 0.60 |
| ARB | 1,999 | 24.2 | 2,801 | 19.9 | < 0.001 | 1,576 | 22.2 | 1,590 | 22.4 | 0.78 |
| Beta blocker | 6,190 | 75.0 | 10,166 | 72.4 | < 0.001 | 5,235 | 73.7 | 5,276 | 74.2 | 0.43 |
| H2-receptor antagonist | 592 | 7.2 | 1,013 | 7.2 | 0.93 | 474 | 6.7 | 515 | 7.3 | 0.18 |
| PPI | 2,697 | 32.7 | 4,372 | 31.1 | 0.01 | 2,198 | 30.9 | 2,254 | 31.7 | 0.31 |
| Statin | 5,165 | 62.6 | 8,722 | 62.1 | 0.43 | 4,387 | 61.7 | 4,378 | 61.6 | 0.88 |
| Antiplatelet | 1,454 | 17.6 | 2,299 | 16.4 | 0.01 | 1,173 | 16.5 | 1,144 | 16.1 | 0.51 |
| Duration of follow-up (months) | ||||||||||
| Mean (SD) | 6.3 (5.2) | 8.3 (6.8) | < 0.001 | 6.7 (5.3) | 6.6 (5.4) | 0.67 | ||||
| Median | 5 | 6 | 5 | 5 | ||||||
| Total all-cause health care cost ($) | ||||||||||
| Mean (SD) | 17,077 (20,794) | 20,236 (27,688) | < 0.001 | 14,317 (14,314) | 13,971 (14,499) | 0.15 | ||||
| Median | 10,128 | 10,982 | 9,367 | 9,075 | ||||||
| Total all-cause medical cost ($) | ||||||||||
| Mean (SD) | 14,098 (19,277) | 17,834 (26,418) | < 0.001 | 11,816 (13,678) | 11,899 (13,885) | 0.72 | ||||
| Median | 7,436 | 8,605 | 6,936 | 6,960 | ||||||
| Bleeding-related medical cost ($) | ||||||||||
| Mean (SD) | 876 (6,073) | 1,798 (8,078) | < 0.001 | 670 (3,447) | 740 (3,695) | 0.24 | ||||
| Median | 0 | 0 | 0 | 0 | ||||||
| Stroke-related medical cost ($) | ||||||||||
| Mean (SD) | 862 (4,796) | 1,466 (6,990) | < 0.001 | 725 (3,651) | 724 (3,605) | 0.99 | ||||
| Median | 0 | 0 | 0 | 0 | ||||||
aP values were calculated for the differences in mean values.
ACE = angiotensin-converting enzyme; ARB = angiotensin receptor blocker; CAD = coronary artery disease; CHF = congestive heart failure; MI = myocardial infarction; PPI = proton pump inhibitor; PVD = peripheral vascular disease; SD = standard deviation; TIA = transient ischemic attack.