Table 1.
The clinical characteristics of the study datasets at patient and image level
| Variables | Patients (N = 1297) | Ultrasound Images (N = 4505) | Ultrasound Images in nontesting dataset (N = 4,010) | Ultrasound Images in testing dataset (N = 495) | p valuea |
|---|---|---|---|---|---|
| Demographics, median (IQR) | |||||
| Age (years) | 65 (53, 74) | 65 (52, 74) | 65 (53, 74) | 63 (51, 74) | 0.269 |
| Male, n (%) | 715 (55.1) | 2464 (54.7) | 2201 (54.9) | 263 (53.1) | 0.459 |
| Comorbidity, n (%) | |||||
| Cardiovascular disease | 1001 (77.2) | 3504 (77.8) | 3117 (77.7) | 387 (78.2) | 0.820 |
| Hypertension | 968 (74.6) | 3405 (75.6) | 3024 (75.4) | 381 (77.0) | 0.446 |
| Diabetes | 533 (41.1) | 1888 (41.9) | 1697 (42.3) | 191 (38.6) | 0.112 |
| Biochemical value, median (IQR) | |||||
| Serum creatinine (mg/dL) | 2.1 (1.4, 4.4) | 2.1 (1.4, 4.3) | 2.1 (1.4, 4.4) | 2.0 (1.4, 3.6) | 0.003 |
| eGFR (mL/min/1.73 m2) | 30.0 (12.3, 48.6) | 30.1 (12.6, 48.7) | 29.9 (12.3, 48.2) | 31.6 (15.7, 55.5) | 0.001 |
| Sonographic parameter, median (IQR) | |||||
| Kidney length (cm) | 9.72 (8.76, 10.53) | 9.62 (8.69, 10.51) | 9.63 (8.66, 10.51) | 9.54 (8.80, 10.48) | 0.703 |
ap values denotes probability for difference between the nontesting and testing datasets and are calculated by Wilcoxon rank sum test for continuous variables and Chi-square test (or Fisher’s exact test as appropriate) for categorical variables