Table 1:
Patient demographics, preoperative characteristics, and perioperative factors before and after propensity score matching
| Before Matching | After Matching | |||||
|---|---|---|---|---|---|---|
| Characteristic | Endo (n=8,206) |
Open (n=6,479) |
Standardized Difference, % | Endo (n=5,928) |
Open (n=5,928) |
Standardized Difference, % |
| Age, years (SD) | 77.7 (6.9) | 77.2 (6.8) | 7 | 77.5 (6.9) | 77.4 (6.8) | 0 |
| Proportion male, % | 43.7 | 50.4 | 13 | 48.5 | 48.3 | 1 |
| Race, % | ||||||
| White | 83.2 | 86.2 | −8 | 85.7 | 85.9 | 0 |
| Black | 12.2 | 10.6 | 0 | 10.5 | 10.6 | 0 |
| Other | 4.7 | 3.2 | 8 | 3.7 | 3.5 | 0 |
| RUCA, % | ||||||
| Urban | 73.6 | 73.3 | 1 | 73.1 | 73.3 | 0 |
| Large Town | 13.1 | 13.8 | −2 | 13.7 | 13.7 | 0 |
| Rural | 13.2 | 12.9 | 1 | 13.3 | 13.0 | 1 |
| Medicaid, % | 22.5 | 19.6 | 7 | 19.8 | 20.0 | 1 |
| Hospital RUCA, % | ||||||
| Urban | 92.0 | 91.9 | 0 | 91.4 | 91.8 | −1 |
| Non-Urban | 8.0 | 8.1 | 0 | 8.6 | 8.2 | 1 |
| Admitted from, % | ||||||
| On referral | 76.1 | 75.1 | 2 | 75.5 | 75.7 | −1 |
| Emergency Department | 18.7 | 19.8 | −3 | 19.2 | 19.0 | 1 |
| On transfer | 5.3 | 5.1 | 1 | 5.3 | 5.3 | 0 |
| Teaching Hospital, % | 50.8 | 53.5 | −5 | 51.6 | 52.4 | 0 |
| Extent of Disease, % | ||||||
| Claudication | 33.5 | 24.1 | 21 | 26.5 | 25.7 | 1 |
| Critical Limb Ischemia | 66.5 | 75.9 | −21 | 73.5 | 74.3 | −1 |
| Myocardial Infarction, % | 11.6 | 9.8 | 6 | 10.4 | 10.2 | 0 |
| CHF / Ischemic Heart Disease, % | 77.2 | 73.7 | 8 | 74.6 | 74.9 | 0 |
| Stroke, % | 15.1 | 14.3 | 2 | 15.0 | 14.8 | 0 |
| Eye Disease, % | 1.2 | 0.9 | 3 | 0.8 | 0.9 | 0 |
| Diabetes, % | 51.3 | 44.2 | 14 | 46.2 | 46.0 | 0 |
| Electrolyte disorder, % | 35.0 | 31.5 | 8 | 32.5 | 32.4 | 2 |
| Renal Failure, % | 27.3 | 21.4 | 14 | 22.6 | 22.5 | 1 |
| Deficiency anemia, % | 37.5 | 33.3 | 9 | 33.9 | 34.0 | 1 |
| Chronic blood loss anemia, % | 5.5 | 5.6 | 0 | 5.6 | 5.5 | 1 |
| Coagulopathy, % | 7.4 | 7.2 | −1 | 7.1 | 7.2 | 0 |
| RA or collagen vascular disease, % | 6.8 | 6.2 | 3 | 6.1 | 6.2 | 0 |
| Chronic pulmonary disease, % | 38.7 | 40.2 | −3 | 39.0 | 39.2 | 1 |
| Hypertension, complicated, % | 77.2 | 77.2 | 0 | 76.8 | 77.0 | 0 |
| Obesity, % | 5.4 | 7.5 | 9 | 5.9 | 5.7 | 1 |
| Paralysis, % | 5.2 | 4.8 | 2 | 4.9 | 4.6 | 1 |
| Neurological disorder, % | 11.1 | 9.6 | 5 | 10.0 | 9.7 | −1 |
| Dementia, % | 4.8 | 5.0 | −1 | 5.0 | 5.0 | −2 |
| Pulmonary circulation disorder, % | 6.5 | 5.6 | 4 | 5.8 | 5.9 | 1 |
| Weight loss, % | 8.0 | 7.9 | 0 | 7.8 | 7.6 | −2 |
| Benign tumor, % | 10.1 | 11.9 | −6 | 11.6 | 11.3 | 0 |
| Cancer, % | 2.8 | 3.0 | −1 | 2.9 | 2.9 | 0 |
| Year, % | ||||||
| 2006 | 30.3 | 32.0 | −4 | 30.9 | 31.2 | 0 |
| 2007 | 26.7 | 25.3 | 3 | 26.0 | 25.9 | 0 |
| 2008 | 23.2 | 22.4 | 2 | 23.1 | 22.8 | 1 |
| 2009 | 19.8 | 20.3 | −1 | 20.0 | 20.1 | −1 |
The standardized differences are reported as percentages; a difference of less than 10% indicates a relatively small imbalance. Endo, endovascular; SD, standard deviation; RUCA, rural urban commuting area; RA, rheumatoid arthritis