| Placebo group (n = 354) | Dexmedetomidine group (n = 356) | RR, HR, or estimated difference (95% CI) a | P value |
---|---|---|---|---|
Primary outcome | ||||
 Overall incidence of delirium | 26 (7.3%) | 17 (4.8%) | RR = 0.650 (0.359, 1.177) | 0.151 |
 Overall incidence of delirium (per-protocol analysis) | 26 (7.5%) (n = 347) | 17 (4.8%) (n = 351) | RR = 0.646 (0.356, 1.170) | 0.145 |
Secondary outcomes | ||||
 Sufentanil equivalent within 5 postoperative days (μg) | 107 (92, 133) | 106 (89, 129) | Median D = -2.6 (-7.5, 2.4) | 0.294 |
 Use of NSAIDs within 5 postoperative days b | 307 (86.7%) | 315 (88.5%) | RR = 1.020 (0.965, 1.078) | 0.477 |
 Length of hospital stay (day) | 5 (5, 6) | 5 (5, 6) | HR = 1.033 (0.891, 1.197) | 0.593 |
 Non-delirium complications within 30 days | 18 (5.1%) | 11 (3.1%) | RR = 0.608 (0.291, 1.268) | 0.179 |
 All-cause 30-day mortality | 0 (0.0%) | 0 (0.0%) | –- |  > 0.999 |
 WHOQOL-BREF, scorec | ||||
  Physical domain | 51.6 ± 14.6 [2] | 55.4 ± 14.3 [5] | Mean D = 3.8 (1.6, 5.9) | 0.001 |
  Psychological domain | 70.3 ± 11.1 [2] | 73.1 ± 13.4 [5] | Mean D = 2.8 (1.0, 4.7) | 0.002 |
  Social relationships domain | 71.9 ± 6.2 [2] | 72.5 ± 5.7 [5] | Mean D = 0.6 (-0.3, 1.5) | 0.176 |
  Environment domain | 61.7 ± 10.8 [2] | 63.1 ± 10.4 [5] | Mean D = 1.4 (-0.1, 3.0) | 0.076 |
 TICS-m, score d | 28.8 ± 5.0 [5] | 28.4 ± 5.0 [10] | Mean D = -0.3 (-1.1, 0.4) | 0.382 |
Exploratory analyses | ||||
 Motoric subtype of delirium |  |  |  | 0.351 |
  None | 328 (92.7%) | 339 (95.2%) |  |  |
  Hypoactive | 20 (5.6%) | 11(3.1%) |  |  |
  Hyperactive | 5 (1.4%) | 4 (1.1%) |  |  |
  Mixed | 1 (0.3%) | 2 (0.6%) |  |  |
 Delirium requiring drug treatment e | 1 (0.3%) | 1 (0.3%) | RR = 0.994 (0.062, 15.836) |  > 0.999 |