Table 1.
Comparison of descriptive characteristics between unmatched GA and RA groups
| Variable | General Anesthesia (N = 20,499) | Regional Anesthesia (N = 21,177) | Test statistic | p-value | Std. Diff. |
|---|---|---|---|---|---|
| Demographics | |||||
| Age, Mean (SD) | 72.8 (5.5) | 74.5 (5.9) | Z = −30.1 | <0.0001* | 0.3* |
| 66–69, N (%) | 7,191 (35.1) | 5,165 (24.4) | X2 = 570.7 (1) | <0.0001* | 0.2* |
| 70–74, N (%) | 6,491 (31.7) | 6,235 (29.4) | X2 = 24.3 (1) | <0.0001* | 0.05* |
| 75–79, N (%) | 4,062 (19.8) | 5,398 (25.5) | X2 = 191.1 (1) | <0.0001* | 0.1* |
| 80–84, N (%) | 2,042 (10.0) | 3,105 (14.7) | X2 = 212.6 (1) | <0.0001* | 0.1* |
| 85+, N (%) | 713 (3.5) | 1,274 (6.0) | X2 = 147.7 (1) | <0.0001* | 0.1* |
| Female sex, N (%) | 8,996 (43.9) | 12,743 (60.2) | X2 = 1107.5 (1) | <0.0001* | 0.3* |
| Medical comorbidity† | |||||
| ADG groups, Mean (SD) | 9.1 (3.3) | 8.9 (3.4) | Z = 5.7 | <0.0001* | 0.05 |
| Charlson comorbidity score, Mean (SD) | 0.6 (1.2) | 0.3 (0.7) | Z = 18.1 | <0.0001* | 0.3* |
| Number of unique medications, Mean (SD) | 6.9 (4.7) | 7.6 (4.7) | Z = −17.0 | <0.0001* | 0.2* |
| Medical conditions†, N (%) | |||||
| Head trauma | 419 (2.0) | 424 (2.0) | X2 = 0.1 (1) | 0.8 | 0 |
| Chronic renal disease | 1,105 (5.4) | 1,215 (5.7) | X2 = 2.4 (1) | 0.1 | 0.02 |
| Diabetes mellitus | 4,464 (21.8) | 5,018 (23.7) | X2 = 21.8 (1) | <0.0001* | 0.05 |
| Congestive heart failure | 585 (2.9) | 738 (3.5) | X2 = 13.5 (1) | 0.0002* | 0.04 |
| Hypertension | 13,633 (66.5) | 15,684 (74.1) | X2 = 285.1 (1) | <0.0001* | 0.17* |
| Ischemic heart disease | 536 (2.6) | 589 (2.8) | X2 = 1.1 (1) | 0.3 | 0.01 |
| Obesity | 220 (1.1) | 330 (1.6) | X2 = 18.8 (1) | <0.0001* | 0.04 |
| Stroke | 1,024 (5.0) | 1,056 (5.0) | X2 = 0.0 (1) | 1.0 | 0 |
| Anxiety disorder | 6,702 (32.7) | 6,738 (31.8) | X2 = 3.7 (1) | 0.1 | 0.02 |
| Depression | 6,848 (33.4) | 7,017 (33.1) | X2 = 0.4 (1) | 0.6 | 0.01 |
| Mood disorders | 1,056 (5.2) | 1,323 (6.2) | X2 = 23.2 (1) | <0.0001* | 0.05 |
| Parkinsonism | 215 (1.0) | 245 (1.2) | X2 = 1.1 (1) | 0.3 | 0.01 |
| Schizophrenia | 103 (0.5) | 108 (0.5) | X2 = 0.01 (1) | 0.9 | 0 |
| Asthma | 1,111 (5.4) | 1,273 (6.0) | X2 = 6.8 (1) | 0.009* | 0.03 |
| COPD | 3,502 (17.1) | 3,855 (18.2) | X2 = 9.0 (1) | 0.003* | 0.03 |
| Medication history† | |||||
| Any antidepressants, N (%) | 745 (3.6) | 1,050 (5.0) | X2 = 44.3 (1) | <0.0001* | 0.07 |
| Any antipsychotics, N (%) | 290 (1.4) | 218 (1.0) | X2 = 12.8 (1) | 0.0003* | 0.04 |
| Any benzodiazepines, N (%) | 2,398 (11.7) | 2,745 (13.0) | X2 = 15.4 (1) | <0.0001* | 0.04 |
| Any opioids, N (%) | 3,227 (15.7) | 5,170 (24.4) | X2 = 486.8 (1) | <0.0001* | 0.2* |
| Any statins, N (%) | 7,450 (36.3) | 8,075 (38.1) | X2 = 14.2 (1) | 0.0002* | 0.04 |
| Anticholinergic risk score, Mean (SD) | 0.3 (0.8) | 0.3 (0.9) | Z = −7.9 | <0.0001* | 0.07 |
| Health services utilization† | |||||
| Any ED visit, N (%) | 5,721 (27.9) | 5,332 (25.2) | X2 = 39.9 (1) | <0.0001* | 0.06 |
| Any inpatient admission, N (%) | 1,139 (5.6) | 907 (4.3) | X2 = 36.2 (1) | <0.0001* | 0.06 |
| Physician visits | |||||
| Family/General practitioner visits, Mean (SD) | 7.4 (5.3) | 7.7 (5.5) | Z = −6.0 | <0.0001* | 0.05 |
| Any geriatrician visit, N (%) | 725 (3.5) | 753 (3.6) | X2 = 0.01 (1) | 0.9 | 0 |
| Any neurologist visit, N (%) | 836 (4.1) | 984 (4.6) | X2 = 8.1 (1) | 0.005* | 0.03 |
| Any psychiatrist visit, N (%) | 327 (1.6) | 321 (1.5) | X2 = 0.4 (1) | 0.5 | 0.01 |
| Home care utilization | |||||
| Any home care service, N (%) | 2,267 (11.1) | 5,299 (25.0) | X2 = 1366.8 (1) | <0.0001* | 0.4* |
| Perioperative | |||||
| Index surgery, N (%) | |||||
| Hip replacement | 2,106 (10.3) | 7,214 (34.1) | X2 = 3395.9 (1) | <0.0001* | 0.6* |
| Hysterectomy | 3,202 (15.6) | 681 (3.2) | X2 = 1897.0 (1) | <0.0001* | 0.4* |
| Inguinal hernia repair | 9,877 (48.2) | 1,460 (6.9) | X2 = 8966.9 (1) | <0.0001* | 1.0* |
| Knee replacement | 3,255 (15.9) | 11,715 (55.3) | X2 = 7039.5 (1) | <0.0001* | 0.9* |
| Prostatectomy | 2,059 (10.0) | 107 (0.5) | X2 = 1923.7 (1) | <0.0001* | 0.4* |
| Hospital LOS days, Mean (SD) | 3.9 (2.6) | 4.4 (2.4) | Z = −28.1 | <0.0001 | 0.2* |
| Physician consultations†, N (%) | |||||
| Any anesthesiologist visit | 10,619 (51.8) | 15,369 (72.6) | X2 = 1914.6 (1) | <0.0001* | 0.4* |
| Any cardiologist visit | 11,286 (55.1) | 10,988 (51.9) | X2 = 42.1 (1) | <0.0001* | 0.06 |
| Any respirology visit | 1,415 (6.9) | 1,519 (7.2) | X2 = 1.2 (1) | 0.3 | 0.01 |
| Type of hospital, N (%) | |||||
| Missing | 495 (2.4) | 115 (0.5) | - | - | 0.2* |
| Community | 14,568 (71.1) | 15,029 (71.0) | X2 = 11.0 (1) | 0.0009* | 0 |
| Small | 350 (1.7) | 118 (0.6) | X2 = 128.8 (1) | <0.0001* | 0.1* |
| Teaching | 5,086 (24.8) | 5,915 (27.9) | X2 = 37.0 (1) | <0.0001* | 0.07 |
| ASA score, N (%) | |||||
| I/II – No Bill code | 11,097 (54.1) | 9,309 (44.0) | X2 = 431.7 (1) | <0.0001* | 0.2* |
| III | 8,726 (42.6) | 11,071 (52.3) | X2 = 393.9 (1) | <0.0001* | 0.2* |
| IV/V | 676 (3.3) | 797 (3.7) | X2 = 6.6 (1) | 0.01* | 0.03 |
| Any Complications, N (%) | 2,247 (11.0) | 4,055 (19.1) | X2 = 543.9 (1) | <0.0001* | 0.2* |
ADG = Aggregated diagnostic groups, ASA = American Society of Anesthesiologists, COPD = Chronic obstructive pulmonary disease, ED = Emergency department, Std. Diff. = Standardized difference
*
Statistically significant
†
Lookback periods: ADG groups, Charlson comorbidity = 3 years preceding index; Number of unique medications = 1 year preceding index; Medical conditions = 5 years preceding index; Medication history = 120 days preceding; Health services utilization = 1 year preceding index; Physician consultations = 90 days preceding index.