Patient demographics.
| Demographics | No ITM (n = 115) | ITM (n = 65) | P |
| Age, y | 64.18 ± 12.45 | 63.88 ± 11.44 | 0.872 |
| Body mass index | 31.72 ± 6.26 | 31.14 ± 6.25 | 0.559 |
| Sex | >0.99 | ||
| Man | 67 (58.3) | 38 (58.5) | |
| Woman | 48 (41.7) | 27 (41.5) | |
| ASA score 3+ | 68 (59.1) | 35 (53.8) | 0.595 |
| Fusion of 3+ levels | 36 (31.3) | 26 (40.0) | 0.309 |
Abbreviations: ASA, American Society of Anesthesiologists; ITM, intrathecal morphine.
Note: Data are expressed as mean ± SD or n (%).