Table 1.
Baseline characteristics
| Characteristics | All patients n = 8543 |
Impacted stones n = 2650 (31.0) |
Non-impacted stones n = 5893 (69.0) |
Difference p value | Type of test |
|---|---|---|---|---|---|
| Age, mean in years (SD) | 47.9 (15.9) (n = 7328) |
49.8 (15.4) (n = 2412) |
47.0 (16.1) (n = 4916) |
<0.001 | C |
| Gender | |||||
| Male n (%) | 5660 (66.3) | 1867 (63.7) | 3973 (67.5) | 0.001 | A |
| Female n (%) | 2875 (33.7) (n = 8535) |
962 (36.3) (n = 2649) |
1913 (32.5) (n = 5886) |
||
| BMI mean (SD) | 26.6 (4.6) (n = 7147) |
26.9 (4.9) (n = 2392) |
26.4 (4.5) (n = 4753) |
<0.001 | C |
| ASA-score n (%) | |||||
| I | 4795 (59.3) | 1254 (49.4) | 3514 (63.9) | <0.001 | A |
| II | 2670 (33.0) | 982 (38.6) | 1688 (30.5) | ||
| III | 587 (7.3) | 288 (11.3) | 299 (5.4) | ||
| IV | 31 (0.4) (n = 8083) |
17 (0.7) (n = 2541) |
14 (0.3) (n = 5542) |
||
| Comorbidity and medication n (%) | |||||
| DM | 840 (9.9) (n = 8485) |
306 (11.6) (n = 2634) |
534 (9.1) (n = 5851) |
<0.001 | A |
| CVD | 2364 (27.7) (n = 8543) |
910 (34.3) (n = 2650) |
1454 (24.7) (n = 5893) |
<0.001 | A |
| Crohn’s disease | 31 (0.4) (n = 8476) |
11 (0.4) (n = 2632) |
20 (0.3) (n = 5844) |
0.59 | A |
| Prednisone | 58 (0.7) (n = 8479) |
23 (0.9) (n = 2635) |
35 (0.6) (n = 5844) |
0.16 | A |
| Anticoagulation | 393 (4.6) (n = 8481) |
166 (6.3) (n = 2633) |
227 (3.9) (n = 5848) |
<0.001 | A |
| Previous stone treatment n (%) | |||||
| URS | 880 (10.4) (n = 8491) |
269 (10.2) (n = 2635) |
611 (10.4) (n = 5856) |
0.75 | A |
| PCNL | 264 (3.1) (n = 8494) |
81 (3.1) (n = 2636) |
183 (3.1) (n = 5858) |
0.090 | A |
| SWL | 1407 (16.6) (n = 8471) |
548 (20.9) (n = 2622) |
859 (14.7) (n = 5849) |
<0.001 | A |
| Ureterolithotomy | 90 (1.1) (n = 8492) |
49 (1.9) (n = 2635) |
41 (0.7) (n = 5857) |
<0.001 | A |
| Pyelolithomy | 94 (1.1) (n = 8500) |
37 (1.4) (n = 2639) |
57 (1.0) (n = 5861) |
0.080 | A |
| Pre-operative positive urine culture n (%) | 488 (5.9) (n = 8264) |
214 (8.3) (n = 2569) |
274 (4.8) (n = 5695) |
<0.001 | A |
| Total stone burden (mm2) median, [IQR] | 53.4, [28–85] (n = 8539) |
58.9, [33–95] (n = 2650) |
50.3, [27–79] (n = 5889) |
<0.001 | D |
| Stone location ureter n (%) | |||||
| Proximal ureter | 2336 (27.3) | 772 (29.1) | 1564 (26.5) | <0.001 | A |
| Mid-ureter | 1784 (20.9) | 601 (22.7) | 1183 (20.1) | ||
| Distal ureter | 4140 (48.5) | 1172 (44.2) | 2968 (50.4) | ||
| Multiple locations | 283 (3.3) (n = 8543) |
105 (4.0) (n = 2650) |
178 (3.0) (n = 5893) |
||
| Ureteral stent n (%) | 1285 (15.1) (n = 8496) |
361 (13.7) (n = 2637) |
924 (15.8) (n = 5859) |
0.013 | A |
| Percutaneous drain n (%) | 309 (3.6) (n = 8498) |
144 (5.5) (n = 2637) |
165 (2.8) (n = 5861) |
<0.001 | A |
ASA American Society of Anesthesiologists, DM Diabetes Mellitus, CVD Cardio Vascular Disease, PCNL Percutaneous Nephrolithotomy, ESWL Extra Corporeal Shockwave Lithotripsy, URS Ureterorenoscopy, UPJ uretero-pelvic junction
NS not significant. Data are n (%) of patients for whom data were available. Percentages exclude missing values from denominators. Statistical test: A Pearson’s Chi-square test, B Fishers exact test, C Student’s t test, D Mann–Whitney U test