Table 1. Stratified Patient Characteristics of the Internal (SHC) and External (Duke) Data Set .
| Variable | No. (%) | |||
|---|---|---|---|---|
| SHC Inpatients (n = 3214) | Duke Inpatients (n = 240) | SHC Outpatients (n = 100) | Duke Outpatients (n = 101) | |
| Age, mean (SD) | 60.53 (19.43) | 70.2 (14.2) | 57.74 (19.87) | 73.06 (15.3) |
| Sex | ||||
| Men | 1510 (47.0) | 108 (45.0) | 33 (33) | 42 (41.83) |
| Women | 1704 (53.0) | 132 (55.0) | 67 (67.0) | 59 (58.4) |
| Race/ethnicity | ||||
| White | 1952 (60.73) | 120 (50.0) | 59 (59.0) | 56 (55.4) |
| Black | 194 (6.03) | 97 (40.4) | 11 (11.0) | 42 (41.6) |
| Asian | 342 (10.65) | 0 | 6 (6.0) | 0 |
| Native American | 65 (0.2) | 10 (0.4) | 5 (5.0) | 0 |
| Other | 413 (12.83) | 10 (0.4) | 9 (9.0) | 1 (0.01) |
| Unknown | 248 (7.71) | 3 (1.3) | 10 (10.0) | 2 (1.1) |
| d-Dimer test | ||||
| Total d-dimer tests | 637 (19.8) | 31 (13.11) | 29 (29.0) | 32 (31.7) |
| Negative d-dimer test result | 42 (6.6) | 30 (96.8) | 2 (2.0) | 4 (4.0) |
| Prior diseases of pulmonary circulation | 495 (15.4) | 35 (14.6) | 55 (55.0) | 13 (12.9) |
| Cancer | 1376 (42.8) | 61 (25.4) | 34 (34.0) | 21 (20.8) |
| Anticoagulant therapy | 1180 (36.7) | 53 (22.1) | 55 (55.0) | 27 (26.53) |
| Ground truth: acute PE-positive | 1967 (61.2) | 38 (15.8) | 29 (29.0) | 23 (22.77) |
Abbreviations: Duke, Duke University Medical Center; PE, pulmonary embolism; SHC, Stanford University hospital and clinics.