Table 1.
Baseline Characteristics of Patients Receiving Regional and General Anesthesia for Hip Fracture Surgerya
| No. (%) of Patients Receiving Anesthesia |
||||
|---|---|---|---|---|
| Regional (n = 15 904) |
General (n = 40 825) |
Absolute Standardized Differenceb |
P Value |
|
| Demographics, nursing home residence, and Medicaid coverage |
||||
| Age, mean (SD), y | 82.2 (9.5) | 81.1 (10.1) | 0.11 | <.001 |
| Women | 4059 (74.5) | 10 686 (73.8) | 0.01 | .11 |
| Race | ||||
| White | 14 235 (89.5) | 35 945 (88.1) | 0.05 | <.001 |
| Black | 399 (2.5) | 1433 (3.5) | 0.06 | <.001 |
| Other | 1270 (8.0) | 3447 (8.4) | 0.02 | <.001 |
| Nursing home resident | 617 (3.9) | 1517 (3.7) | <0.01 | .36 |
| Medicaid eligible | 2536 (16.0) | 6900 (16.9) | 0.03 | .006 |
| Common comorbidities, present in more than 3% of the study population |
||||
| Dementia | 4060 (25.5) | 10 411 (25.5) | <0.01 | .95 |
| Prior stroke | 1116 (7.0) | 2989 (7.3) | 0.01 | .21 |
| Congestive heart failure | 2546 (16.0) | 6770 (16.6) | 0.02 | .10 |
| Myocardial infarction | 957 (6.0) | 2301 (5.7) | 0.02 | .100 |
| Past cardiac arrhythmia | 3392 (21.3) | 9237 (22.6) | 0.03 | <.001 |
| Cardiac valvular disease | 1861 (11.7) | 5336 (13.1) | 0.04 | <.001 |
| Hypertension | 10 500 (66.0) | 27 521 (67.4) | 0.03 | .002 |
| Chronic lung disease | 3206 (20.2) | 6443 (15.8) | 0.11 | <.001 |
| Renal failure | 127 (7.0) | 485 (8.2) | 0.05 | <.001 |
| Diabetes mellitus | 3218 (20.2) | 8810 (21.6) | 0.03 | <.001 |
| Electrolyte abnormality | 2771 (17.4) | 7298 (17.9) | 0.01 | .21 |
| Thrombocytopenia | 396 (2.5) | 1383 (3.4) | 0.05 | <.001 |
| Cancer | 2117 (13.3) | 5032 (12.3) | 0.03 | .002 |
| Fracture type | ||||
| Femoral neck | 7647 (48.1) | 19 157 (46.9) | 0.02 | .95 |
| Intertrochanteric | 7312 (46.0) | 18 919 (46.3) | <0.01 | .44 |
| Subtrochanteric | 617 (3.9) | 1698 (4.7) | 0.04 | <.001 |
| ≥2 | 328 (2.1) | 838 (2.1) | <0.01 | .01 |
| Procedure | ||||
| Total hip arthroplasty | 596 (3.8) | 1698 (4.2) | 0.02 | .03 |
| Hemiarthroplasty | 5394 (33.9) | 13 184 (32.3) | 0.03 | <.001 |
| Internal fixation | 9914 (62.3) | 25 943 (63.6) | 0.02 | .008 |
| Residential zip code area characteristics, mean (SD) |
||||
| Median income, $ | 53 802 (22 512) |
50 746 (19 770) |
0.14 | <.001 |
| Below poverty, % | 11.0 (7.8) | 11.2 (8.6) | 0.03 | .06 |
| Completing college, % | 29.6 (16.7) | 28.4 (14.9) | 0.08 | .01 |
| Completing high school, % | 82.7 (9.4) | 82.6 (9.4) | 0.02 | .72 |
| Hospital characteristics, mean (SD) | ||||
| No. of beds | 381 (376) | 524 (422) | 0.35 | <.001 |
| Nurse skill mixc | 90.7 (7.2) | 91.7 (7.2) | 0.13 | <.001 |
| Nurse to bed ratiod | 1.56 (0.4) | 1.55 (0.5) | 0.03 | <.001 |
| Teaching hospital, % | 3720 (23.4) | 13 939 (34.1) | 0.24 | <.001 |
| Trauma center, % | 2264 (14.2) | 7239 (17.7) | 0.10 | <.001 |
a
Data are unadjusted. Selected variables shown; additional results appear in the Appendix.
b
The standardized difference for each variable is the mean difference between patients in each group as a fraction of the pooled standard deviation across both groups.
c
Nurse skill mix equals the total number of full-time-employee registered nurses and licensed practical nurses divided by total number of full-time employee nurses.
d
Nurse to bed ratio calculated as total number of full-time employee nurses divided by total number of hospital beds.