Table 1. Patient characteristics before and after propensity score matching.
| Complete Cohort | Propensity Score Matched Cohort* | |||
|---|---|---|---|---|
| Non-Users (N = 252544) | Aspirin Users (N = 81830) | Non-Users (N = 81830) | Aspirin Users (N = 81830) | |
| Matched Patient Characteristics | ||||
| Age (years), mean (SD) | 57.7 (16.4) | 69.6 (10.8) | 69.6 (10.8) | 69.6 (10.8) |
| Male | 217090 (86.0%) | 77245 (94.4%) | 77245 (94.4%) | 77245 (94.4%) |
| CAN 1 Year Mortality Score, mean (SD) | 38.8 (30.3) | 57.3 (26.7) | 57.3 (26.7) | 57.3 (26.7) |
| Non-Matched Patient Characteristics | ||||
| Race and/or Ethnicity | ||||
| Non-Hispanic White | 140166 (55.5%) | 50167 (61.3%) | 49468 (60.5%) | 50167 (61.3%) |
| Non-Hispanic Black or African American | 59295 (23.5%) | 18775 (22.9%) | 18778 (22.9%) | 18775 (22.9%) |
| Hispanic | 28784 (11.4%) | 6442 (7.9%) | 6673 (8.2%) | 6442 (7.9%) |
| Asian | 3767 (1.5%) | 660 (0.8%) | 643 (0.8%) | 660 (0.8%) |
| American Indian or Alaska Native | 2638 (1.0%) | 779 (1.0%) | 813 (1.0%) | 779 (1.0%) |
| Native Hawaiian/Other Pacific Islander | 2266 (0.9%) | 687 (0.8%) | 659 (0.8%) | 687 (0.8%) |
| Declined | 12178 (4.8%) | 3711 (4.5%) | 3864 (4.7%) | 3711 (4.5%) |
| Missing | 3450 (1.4%) | 609 (0.7%) | 932 (1.1%) | 609 (0.7%) |
| Aspirin Dosage (mg/day), mean (SD) | NA | 98.4 (61.9) | NA | 98.4 (61.9) |
| 81 mg/day | NA | 76976 (91.6%) | NA | 76976 (91.6%) |
| 162 mg/day | NA | 1172 (1.4%) | NA | 1172 (1.4%) |
| 243 mg/day | NA | 50 (0.1%) | NA | 50 (0.1%) |
| 325 mg/day | NA | 3022 (3.7%) | NA | 3022 (3.7%) |
| 405–650 mg/day | NA | 45 (0.0%) | NA | 45 (0.0%) |
| No Dose Listed (Non-VA prescription) | NA | 565 (0.7%) | NA | 565 (0.7%) |
| CCI Score, mean (SD) | 2.23 (2.90) | 4.14 (3.21) | 3.92 (3.22) | 4.14 (3.21) |
| Body Mass Index (BMI), mean (SD) | 30.8 (6.42) | 30.6 (6.24) | 29.9 (6.29) | 30.6 (6.24) |
| Common Comorbidities Prior to COVID-19 Diagnosis | ||||
| Congestive Heart Failure | 26305 (10.4%) | 20604 (25.2%) | 14140 (17.3%) | 20604 (25.2%) |
| Chronic Pulmonary Disease | 82704 (32.7%) | 38334 (46.8%) | 35478 (43.4%) | 38334 (46.8%) |
| Chronic Kidney Disease | 33428 (13.2%) | 21198 (25.9%) | 17295 (21.1%) | 21198 (25.9%) |
| Diabetes | 32874 (13.0%) | 16500 (20.2%) | 13778 (16.8%) | 16500 (20.2%) |
| Hypertension | 134755 (53.4%) | 71040 (86.8%) | 59741 (73.0%) | 71040 (86.8%) |
| Inpatient for COVID-19 | 78586 (31.1%) | 35212 (43.0%) | 35057 (42.8%) | 35212 (43.0%) |
| Vaccinated status for COVID-19 | ||||
| Unvaccinated at time of COVID diagnosis | 173230 (68.6%) | 55193 (67.4%) | 55693 (68.1%) | 56602 (67.4%) |
| Vaccinated at time of COVID diagnosis | 79314 (31.4%) | 26637 (32.6%) | 26137 (31.9%) | 27403 (32.6%) |
| Number Vaccine Doses prior to COVID-19 Diagnosis | ||||
| Unvaccinated | 173230 (68.6%) | 55193 (67.4%) | 55693 (68.1%) | 55193 (67.4%) |
| 1 Dose | 8855 (3.5%) | 2157 (2.6%) | 2345 (2.9%) | 2157 (2.6%) |
| 2 Doses | 37887 (15.0%) | 10879 (13.3%) | 10869 (13.3%) | 10879 (13.3%) |
| 3 Doses | 32572 (12.9%) | 13601 (16.6%) | 12923 (15.8%) | 13601 (16.6%) |
| Death within follow-up period | 26254 (10.4%) | 7531 (9.2%) | 13890 (17.0%) | 7531 (9.2%) |
CAN = Care Assessment Needs, CCI = Charelson Comorbidity Index
*Propensity Score Matching was performed using the “nearest neighbor” method in R Studio (Version 3.6.2) through the “MatchIt” library, matching on the covariates of age, gender, and the VA’s Care Assessment of Needs (CAN) 1-Year Mortality Score.