Table 1 Patient demographics and stone characteristics
| Characteristic | USa | FS | p value |
|---|---|---|---|
| Number of patients | 209 | 216 | |
| Patient age (mean ± SD) | 53.3 ± 13.2 | 53.8 ± 12.4 | 0.568 |
| Patient gender | 0.016 | ||
| Male, n (%) | 130 (62.2%) | 158 (73.1%) | |
| Female, n (%) | 79 (37.8%) | 58 (26.8%) | |
| Stone size (cm) | 1.03 ± 0.37 | 0.87 ± 0.33 | 0.008 |
| > 1 cm (n) | 111 | 73 | |
| < 1 cm (n) | 98 | 143 |