Table 1. Baseline Patient Characteristics.
| Characteristic | Patients, No. (%) | SMD | |
|---|---|---|---|
| Surgical group (n = 303 709) | Control group (n = 605 140) | ||
| Sex | |||
| Female | 245 819 (80.9) | 500 929 (82.8) | 0.048 |
| Male | 57 890 (19.1) | 104 211 (17.2) | |
| Age, mean (SD), y | 40.2 (11.9) | 40.4 (12.5) | 0.016 |
| Age, y | |||
| 18-29 | 66 175 (21.8) | 138 336 (22.9) | 0.089 |
| 30-39 | 82 835 (27.3) | 170 763 (28.2) | |
| 40-49 | 81 660 (26.9) | 142 604 (23.6) | |
| 50-59 | 55 058 (18.1) | 110 140 (18.2) | |
| ≥60 | 17 981 (5.9) | 43 297 (7.1) | |
| BMI | |||
| 30-40: Moderate to severe obesity | 126 228 (41.6) | 404 796 (66.9) | 0.527 |
| >40-50: Morbid obesity | 152 557 (50.2) | 175 201 (29.0) | |
| >50: Extreme obesity | 24 924 (8.2) | 25 143 (4.2) | |
| CCI, mean (SD) | 0.52 (1.39) | 0.45 (1.37) | 0.047 |
| CCI | |||
| 0 | 233 064 (76.7) | 485 970 (80.3) | 0.093 |
| 1-2 | 56 626 (18.6) | 92 051 (15.2) | |
| 3-4 | 9996 (3.3) | 18 777 (3.1) | |
| >4 | 4023 (1.3) | 8342 (1.4) | |
| Bariatric procedure | |||
| Adjustable gastric banding | 39 453 (13.0) | NA | NA |
| Biliopancreatic diversion | 1157 (0.4) | NA | |
| Gastric bypass | 84 187 (27.7) | NA | |
| Sleeve gastrectomy | 178 912 (58.9) | NA | |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); CCI, Charlson Comorbidity Index; NA, not applicable; SMD, standardized mean difference.