Table 1.
Baseline Characteristics of Bariatric Surgery Patients and Nonsurgery Controls Pre- and Post-Propensity Score Matching
| Before Matching | After Matching | |||||
|---|---|---|---|---|---|---|
| Surgery (n = 714) | Controls (n = 1,411) | P | Surgery (n = 714) | Controls (n = 714) | Absolute Std Diff | |
| Age, y | 58.1 ± 8.46 | 60.1 ± 8.86 | <0.001 | 58.1 ± 8.46 | 58.4 ± 8.90 | 0.03 |
| Weight, lb | 269.8 ± 49.76 | 276.0 ± 53.11 | 0.009 | 269.8 ± 49.76 | 269.9 ± 51.39 | 0.003 |
| BMI, kg/m2 | 44.3 ± 6.60 | 44.2 ± 7.19 | 0.6 | 44.3 ± 6.60 | 44.0 ± 7.16 | 0.03 |
| Female sex | 551 (77.2%) | 914 (64.8%) | <0.001 | 551 (77.2%) | 543 (76.1%) | 0.03 |
| Race/ethnicity | 0.6 | 0.05 | ||||
| Non-Hispanic white | 399 (55.9%) | 757 (53.6%) | 399 (55.9%) | 404 (56.6%) | ||
| Non-Hispanic black | 131 (18.3%) | 264 (18.7%) | 131 (18.3%) | 131 (18.3%) | ||
| Hispanic | 160 (22.4%) | 328 (23.2%) | 160 (22.4%) | 161 (22.5%) | ||
| Other/missing/unknown | 24 (3.4%) | 62 (4.5%) | 24 (3.4%) | 18 (2.6%) | ||
| Hypertension | 648 (90.8%) | 1317 (93.3%) | 0.03 | 648 (90.8%) | 645 (90.3%) | 0.01 |
| Diabetes | 470 (65.8%) | 933 (66.1%) | 0.9 | 470 (65.8%) | 487 (68.2%) | 0.05 |
| Serum creatinine, mg/dL | 1.4 ± 0.50 | 1.5 ± 0.57 | <0.001 | 1.4 ± 0.50 | 1.5 ± 0.56 | 0.09 |
| eGFR, mL/min/1.73 m2 | 48.2 ± 10.12 | 46.9 ± 10.97 | 0.01 | 48.2 ± 10.12 | 47.1 ± 11.09 | 0.1 |
Note: Values for categorical variables are given as count (proportion); for continuous variables, as mean ± standard deviation. Matching was done with age, weight, sex, race/ethnicity, and presence of hypertension and/or type 2 diabetes. Conversion factor for serum creatinine in mg/dL to μmol/L, ×88.4.
Abbreviations: BMI, body mass index; eGFR, estimated glomerular filtration rate; Std Diff, standardized difference.