Table 1.
Baseline characteristics of the study population.
| Variable | Total N = 521 (%) | Choledocholithiasis on ERCP N = 293 (%) | No choledocholithiasis on ERCP N = 228 (%) | p value |
|---|---|---|---|---|
| Gender, female | 409 (78) | 236 (80) | 173 (76) | 0.20 |
| Race, Hispanic | 388 (74) | 215 (73) | 173 (76) | 0.81 |
| Very strong predictors | ||||
| Total bilirubin > 4 mg/dL | 167 (32) | 120 (41) | 47 (21) | <0.001 |
| Common bile duct stone on ultrasound | 43 (8) | 38 (13) | 5 (2) | <0.001 |
| Clinical ascending cholangitis | 23 (4) | 19 (7) | 4 (2) | <0.01 |
| Strong predictors | ||||
| Total bilirubin, 1.8–4.0 mg/dL | 172 (33) | 93 (32) | 79 (35) | 0.48 |
| Dilated common bile duct on ultrasound | 260 (50) | 171 (59) | 89 (39) | <0.001 |
| Moderate predictors | ||||
| Abnormal liver function tests | 499 (95) | 286 (98) | 213 (93) | 0.02 |
| Age > 55 years | 86 (16) | 54 (19) | 32 (14) | 0.18 |
| Gallstone pancreatitis | 134 (26) | 64 (22) | 70 (31) | 0.02 |
| Very strong predictors | <0.001 | |||
| None | 316 (61) | 143 (49) | 173 (76) | |
| One | 177 (34) | 125 (43) | 52 (23) | |
| Two | 27 (5) | 24 (8) | 3 (1) | |
| Three | 1 (0.2) | 1 (0.3) | (0) | |
| Strong predictors | <0.01 | |||
| None | 158 (30) | 75 (26) | 83 (37) | |
| One | 294 (56) | 171 (58) | 123 (54) | |
| Two | 69 (13) | 47 (16) | 22 (10) | |
| Moderate predictors | 0.33 | |||
| None | 18 (3) | 7 (2) | 11 (5) | |
| One | 323 (62) | 189 (65) | 134 (59) | |
| Two | 154 (30) | 82 (28) | 72 (32) | |
| Three | 26 (5) | 15 (5) | 11 (5) | |
| High probability | 264 (51) | 189 (65) | 75 (33) | <0.001 |
| Intermediate probability | 249 (48) | 102 (35) | 147 (65) | <0.001 |
| Low probability | 8 (2) | 2 (1) | 6 (3) | 0.07 |
ERCP, endoscopic retrograde cholangiopancreatography; CBD, common bile duct; US, ultrasound; LFT, liver function test.