Table 2.
Balance on 44 covariates in matched pairs, regional-vs-general anesthesia. Type 1 pairs finely balance the 47 hospitals, while type 2 pairs make contrasts between hospitals with different usual practices.
| Finely Balanced Pairs (type 1) | Usual Practice Pairs (type 2) | |||
|---|---|---|---|---|
|
| ||||
| Covariate | Regional | General | Regional | General |
| Propensity score (mean) | 52.3 | 52.3 | 52.7 | 52.6 |
| Risk score (mean) | 0.003 | 0.002 | 0.002 | 0.002 |
| Knee 8154 % | 97.5 | 97.0 | 98.9 | 99.0 |
| Knee 8155 % | 2.5 | 3.0 | 1.1 | 1.0 |
| Age (mean) | 72.4 | 72.5 | 72.6 | 72.4 |
| Sex % Female | 64.0 | 65.5 | 64.4 | 63.1 |
| White % | 92.8 | 92.8 | 95.9 | 95.8 |
| Black % | 2.8 | 3.4 | 2.1 | 2.0 |
| Emergency Room Admission % | 0.4 | 0.3 | 0.0 | 0.0 |
| Body Mass Index, BMI (mean) | 31.2 | 31.4 | 31.4 | 31.2 |
| BMI<18 % | 0.3 | 0.3 | 0.0 | 0.0 |
| BMI ge 30 % | 52.4 | 52.4 | 54.1 | 54.1 |
| Height (mean) | 65.7 | 65.6 | 65.9 | 66.1 |
| ASA Score, 1-5 (mean) | 2.5 | 2.5 | 2.5 | 2.5 |
| ASA Score missing % | 1.3 | 1.6 | 0.8 | 0.8 |
| Systolic blood pressure (mean) | 143.0 | 143.0 | 142.5 | 142.9 |
| Blood pressure missing % | 1.4 | 1.0 | 0.2 | 0.2 |
| APACHE Score (mean) | 22.4 | 22.6 | 22.3 | 22.4 |
|
| ||||
| Comorbid Conditions | ||||
|
| ||||
| Diabetic on medication % | 15.7 | 15.2 | 13.9 | 15.4 |
| Diabetic score, 1-3 (mean) | 0.4 | 0.4 | 0.3 | 0.4 |
| Number of cardiac comorbidities (mean) | 0.4 | 0.4 | 0.4 | 0.4 |
| Congestive heart failuare % | 6.5 | 5.8 | 4.1 | 5.2 |
| Past MI % | 4.3 | 3.9 | 3.9 | 4.1 |
| Past arrhythmia % | 14.7 | 15.1 | 16.0 | 16.5 |
| Unstable angina % | 0.5 | 0.9 | 1.0 | 0.4 |
| Angina % | 2.0 | 2.5 | 2.3 | 1.5 |
| Hypertension % | 81.3 | 81.2 | 78.8 | 79.6 |
| Coagulopathy % | 0.2 | 0.1 | 0.0 | 0.0 |
| Stroke % | 3.8 | 4.6 | 1.1 | 1.5 |
| Dementia % | 2.1 | 1.5 | 0.6 | 1.5 |
| Electrolyte abnormality % | 2.3 | 2.7 | 1.9 | 2.4 |
| Valvulardis % | 10.4 | 10.1 | 8.2 | 8.2 |
| Chronic pulmonary disease % | 11.0 | 11.4 | 8.8 | 10.6 |
| Asthma % | 5.9 | 6.2 | 5.9 | 7.1 |
| Liver disease % | 1.2 | 1.3 | 0.1 | 0.3 |
| Renal dysfunction % | 2.0 | 2.3 | 0.5 | 0.6 |
| Renal failure % | 1.5 | 1.5 | 0.3 | 0.3 |
| Paraplegia % | 0.2 | 0.4 | 0.1 | 0.1 |
| Smoking history % | 5.3 | 6.3 | 2.6 | 3.0 |
| Pulmonary fibrosis % | 1.8 | 2.7 | 1.1 | 1.1 |
| Cancer % | 13.3 | 13.9 | 12.1 | 12.8 |
| Abdominal cancer % | 0.1 | 0.0 | 0.0 | 0.0 |
| Weight loss % | 0.2 | 0.2 | 0.1 | 0.1 |
| Sleep apnea % | 1.0 | 0.7 | 0.1 | 0.2 |