Table 2.
Baseline characteristics of patients presenting to the emergency department (ED) with renal colic and CT-confirmed ureteral stones, stratified by stone size and management. Continuous variables are presented as median with interquartile range (IQR), categorical variables as n (%). N indicates the number of patients with available data for the respective variable. Bold values indicate statistical significance at p < 0.05. Abbreviations: BMI: body mass index. HU: Hounsfield units. IQR: interquartile range. 1Median (Q1, Q3); n (%). 2Wilcoxon rank sum test; pearson’s Chi-squared test; fisher’s exact test
| Characteristics | N | Maximum ureteral stone size <6 mm | N | Maximum ureteral stone size ≥6 mm | ||||
|---|---|---|---|---|---|---|---|---|
| Discharge N = 4141 |
Inpatient admission and intervention N = 1001 |
p-value2 | Discharge N = 1071 |
Inpatient admission and intervention N = 1311 |
p-value2 | |||
| Age [years] | 514 | 44.5 (33.0, 56.0) | 49.0 (37.0, 60.0) | 0.066 | 238 | 49.0 (41.0, 57.0) | 53.0 (41.0, 65.0) | 0.07 |
| BMI [kg/m2] | 164 | 26.3 (23.2, 29.6) | 26.7 (23.5, 30.8) | 0.8 | 164 | 26.9 (24.4, 31.4) | 26.3 (23.7, 30.1) | 0.4 |
| Sex | 513 | 0.7 | 238 | 0.15 | ||||
| Female | 103 (25%) | 23 (23%) | 23 (21%) | 39 (30%) | ||||
| Male | 310 (75%) | 77 (77%) | 84 (79%) | 92 (70%) | ||||
| Arrival at the ED | 347 | > 0.9 | 158 | 0.1 | ||||
| By ambulance | 142 (52%) | 40 (53%) | 30 (42%) | 47 (55%) | ||||
| Independently | 129 (48%) | 36 (47%) | 42 (58%) | 39 (45%) | ||||
| Diabetes mellitus | 462 | 27 (7.4%) | 6 (6.3%) | 0.7 | 221 | 8 (8.5%) | 15 (12%) | 0.4 |
| Pain character | 412 | 0.1 | 175 | 0.018 | ||||
| Colicky | 283 (84%) | 59 (77%) | 67 (83%) | 63 (67%) | ||||
| Constant | 52 (16%) | 18 (23%) | 14 (17%) | 31 (33%) | ||||
| Pain duration [h] | 386 | 5.0 (3.0, 20.0) | 11.0 (5.0, 72.0) | < 0.001 | 168 | 11.0 (4.0, 48.0) | 10.0 (4.0, 36.0) | 0.7 |
| Nausea | 271 | 114 (52%) | 34 (64%) | 0.12 | 106 | 23 (55%) | 40 (63%) | 0.4 |
| Vomiting | 269 | 81 (37%) | 23 (46%) | 0.2 | 102 | 11 (27%) | 32 (52%) | 0.01 |
| Fever | 360 | 5 (1.7%) | 3 (4.6%) | 0.2 | 157 | 2 (2.7%) | 6 (7.2%) | 0.3 |
| Macrohematuria | 255 | 26 (12%) | 2 (4.5%) | 0.2 | 110 | 10 (21%) | 8 (13%) | 0.2 |
| Analgesia before ED presentation | 514 | 390 (94%) | 94 (94%) | > 0.9 | 238 | 100 (93%) | 122 (93%) | > 0.9 |
| History of stones | 278 | 104 (47%) | 32 (57%) | 0.2 | 126 | 35 (61%) | 47 (68%) | 0.4 |
| Systolic blood pressure on admission [mmHg] | 395 | 147.0 (137.0, 160.0) | 147.0 (133.0, 165.0) | 0.6 | 163 | 150.5 (136.0, 163.0) | 149.0 (134.0, 165.0) | 0.8 |
| Diastolic blood pressure on admission [mmHg] | 394 | 89.0 (81.0, 99.0) | 89.0 (80.0, 99.0) | 0.7 | 163 | 89.5 (80.0, 98.0) | 88.0 (78.0, 98.0) | 0.4 |
| Heart rate on admission [bpm] | 391 | 76.0 (67.0, 87.0) | 75.0 (67.0, 83.0) | > 0.9 | 158 | 76.0 (65.0, 86.0) | 76.0 (68.0, 86.0) | 0.8 |
| Temperature on admission [°C] | 369 | 36.6 (36.3, 36.9) | 36.7 (36.3, 37.0) | 0.1 | 161 | 36.7 (36.4, 37.0) | 36.6 (36.3, 37.0) | > 0.9 |
| Respiratory rate on admission | 184 | 14.0 (14.0, 16.0) | 15.0 (14.0, 16.0) | 0.079 | 79 | 14.0 (14.0, 16.0) | 14.0 (14.0, 16.0) | 0.9 |
| Creatinine [mg/dl] | 514 | 1.0 (0.9, 1.2) | 1.2 (1.0, 1.4) | < 0.001 | 235 | 1.0 (0.9, 1.2) | 1.1 (1.0, 1.4) | 0.002 |
| eGFR [ml/min] | 508 | 84.0 (69.0, 100.0) | 71.5 (56.0, 95.0) | < 0.001 | 235 | 81.0 (68.0, 94.0) | 69.0 (49.0, 87.0) | < 0.001 |
| CRP [mg/dl] | 443 | 0.2 (0.1, 0.4) | 0.3 (0.1, 1.4) | < 0.001 | 204 | 0.4 (0.1, 0.9) | 0.3 (0.2, 1.8) | 0.5 |
| Leukocytes [G/l] | 513 | 9.5 (7.6, 11.9) | 10.9 (7.8, 13.6) | 0.012 | 235 | 9.8 (7.9, 11.5) | 10.6 (8.2, 12.6) | 0.05 |
| Urine: Nitrite positive | 514 | 9 (2%) | 5 (5.0%) | 0.032 | 238 | 5 (5%) | 11 (8%) | 0.5 |
| Urine: Leukocyturia | 514 | 194 (47%) | 38 (38%) | 0.11 | 238 | 51 (48%) | 74 (56%) | 0.2 |
| Urine: Microhematuria | 514 | 334 (81%) | 69 (69%) | 0.011 | 238 | 90 (84%) | 99 (76%) | 0.11 |
| Urine: Bacteriuria | 514 | 386 (93%) | 93 (93%) | > 0.9 | 238 | 98 (92%) | 125 (95%) | 0.2 |
| Urine culture positive | 146 | 3 (3.3%) | 5 (9.3%) | 0.15 | 87 | 2 (7.1%) | 10 (17%) | 0.3 |
| Location of symptomatic stone | 506 | 0.6 | 236 | < 0.001 | ||||
| Proximal | 73 (18%) | 20 (20%) | 38 (36%) | 72 (55%) | ||||
| Mid ureter | 50 (12%) | 15 (15%) | 14 (13%) | 25 (19%) | ||||
| Distal | 283 (70%) | 65 (65%) | 53 (50%) | 34 (26%) | ||||
| Largest ureteral stone diameter [mm] | 514 | 4.0 (3.1, 4.7) | 4.5 (3.3, 5.1) | 0.002 | 238 | 6.8 (6.3, 8.1) | 8.4 (7.1, 10.2) | < 0.001 |
| Mean HU | 497 | 434.7 (323.0, 570.0) | 464.9 (341.8, 686.5) | 0.067 | 238 | 753.5 (554.3, 882.1) | 914.0 (681.4, 1,138.4) | < 0.001 |
| Hydronephrosis | 514 | 352 (85%) | 91 (91%) | 0.12 | 238 | 91 (85%) | 124 (95%) | 0.013 |
| ED treatment duration [h] | 509 | 4.0 (3.0, 6.0) | 4.0 (3.0, 5.0) | 0.2 | 234 | 4.0 (3.0, 5.0) | 4.0 (3.0, 6.0) | 0.1 |