Table 1.
The baseline characteristics of surgical patients
| Parameter | Overall (8–18), n=5427 | Groups 8–13, n=2802 | Groups 13–18, n=2625 | P |
|---|---|---|---|---|
| Age (year), mean±s.d. | 70.6±7.7 | 70.8±7.5 | 70.5±7.9 | 0.151 |
| Prostate volume (ml), mean±s.d. | 64.8±33.1 | 62.8±31.7 | 67.8±36.0 | <0.001 |
| PSA (ng ml−1), mean±s.d. | 7.4±9.9 | 7.9±8.7 | 6.7±10.7 | <0.001 |
| Urinary tract infection, n (%) | 1541 (28.4) | 830 (29.6) | 711 (27.1) | 0.038 |
| Bladder stones, n (%) | 662 (12.2) | 316 (11.3) | 346 (13.2) | 0.032 |
| Acute urinary retention, n (%) | 700 (12.9) | 421 (15.0) | 279 (10.6) | <0.001 |
| Renal failure, n (%) | 228 (4.2) | 147 (5.2) | 81 (3.1) | <0.001 |
| Hypertension, n (%) | 1536 (28.3) | 757 (27.0) | 779 (29.7) | 0.030 |
| Diabetes mellitus, n (%) | 640 (11.8) | 305 (10.9) | 335 (12.8) | 0.032 |
| Pulmonary disease, n (%) | 401 (7.4) | 188 (6.7) | 213 (8.1) | 0.048 |
| Cardiac disease, n (%) | 341 (6.3) | 161 (5.7) | 180 (6.9) | 0.092 |
| Cerebral disease, n (%) | 223 (4.1) | 115 (4.1) | 108 (4.1) | 0.985 |
P values were determined by analysis of variance and Chi-square tests and compared between groups 8–13 and groups 13–18. PSA: prostate-specific antigen; s.d.: standard deviation