Table 1.
Patient, baseline and interventional characteristics
| Benzodiazepine premedicationa (n=1521)b | No benzodiazepine premedicationa (n=7936)b | |||
| Age (years) | 83.9 ± 3.5; 83 [80 to 100] | 84.3i | 84.4 ± 3.9; 83 [80 to 104] | 84.3 |
| Sex | ||||
| Male | 715 (47.0%) | 46.8%j | 3752 (47.3%) | 47.3% |
| Female | 806 (53.0%) | 53.2% | 4184 (52.7%) | 52.7% |
| Multimorbidityc | ||||
| No | 336 (22.1%) | 21.4% | 1817 (22.9%) | 22.6% |
| Yes | 1185 (77.9%) | 78.6% | 6119 (77.1%) | 77.4% |
| Limited mobility TUG testd | ||||
| Limited | 1037 (78.0%) | 77.6% | 5395 (77.0%) | 77.2% |
| Normal | 293 (22.0%) | 22.4% | 1612 (23.0%) | 22.8% |
| Missing | 191 | 929 | ||
| Mini-Cog score ≤3 pointse | ||||
| No | 608 (40.0%) | 42.4% | 3477 (43.8%) | 43.3% |
| Yes | 913 (60.0%) | 57.6% | 4459 (56.2%) | 56.7% |
| Frailtyf | ||||
| No | 1372 (90.2%) | 85.4% | 6752 (85.1%) | 85.9% |
| Yes | 149 (9.8%) | 14.6% | 1184 (14.9%) | 14.1% |
| Chronic benzodiazepine | ||||
| No | 1268 (83.4%) | 87.3% | 6973 (87.9%) | 87.2% |
| Yes | 253 (16.6%) | 12.7% | 958 (12.1%) | 12.8% |
| Referring facility | ||||
| Home | 1359 (89.4%) | 88.3% | 6825 (86%) | 86.6% |
| Other hospital | 23 (1.5%) | 1.8% | 159 (2%) | 1.9% |
| Rehabilitation | 3 (0.2%) | 0.5% | 57 (0.7%) | 0.6% |
| Nursing home | 64 (4.2%) | 6.5% | 604 (7.6%) | 7.1% |
| Other | 72 (4.7%) | 2.9% | 288 (3.6%) | 3.7% |
| Missing | 0 | 3 | ||
| Type of intervention | ||||
| Abdominal | 166 (10.9%) | 12.6% | 978 (12.3%) | 12.2% |
| Cardiovascular | 177 (11.6%) | 9.3% | 710 (9.0%) | 9.4% |
| ENT | 442 (29.1%) | 15.6% | 1151 (14.5%) | 16.6% |
| Gynaecological | 201 (13.2%) | 15.8% | 1229 (15.5%) | 15.2% |
| Interventional | 91 (6.0%) | 10.0% | 933 (11.8%) | 10.9% |
| Neurosurgery | 14 (0.9%) | 1.9% | 181 (2.3%) | 2.1% |
| Othopaedic | 381 (25.1%) | 30.8% | 2465 (31.1%) | 30.1% |
| Other surgery | 49 (3.2%) | 4.0% | 289 (3.6%) | 3.6% |
| Severity of intervention | ||||
| Minor | 311 (20.5%) | 19.1% | 1629 (20.5%) | 20.5% |
| Intermediate | 588 (38.7%) | 38.0% | 3012 (38.0%) | 38.0% |
| Major | 622 (40.9%) | 42.9% | 3295 (41.5%) | 41.5% |
| Urgency of intervention | ||||
| Elective | 1295 (85.1%) | 76.2% | 5852 (73.7%) | 75.5% |
| Urgent | 185 (12.2%) | 18.7% | 1648 (20.8%) | 19.4% |
| emergency | 41 (2.7%) | 5.1% | 436 (5.5%) | 5.1% |
| Anaesthesia technique | ||||
| Combinedg | 174 (11.4%) | 11.7% | 881 (11.1%) | 11.2% |
| General | 609 (40.0%) | 52.7% | 4420 (55.7) | 53.3% |
| Regionalh | 285 (18.7%) | 18.1% | 1340 (16.9%) | 17.2% |
| Sedation | 453 (29.8%) | 17.5% | 1295 (16.3%) | 18.3% |
| Transfusion of red blood cells | ||||
| No | 1407 (92.6%) | 94.0% | 7476 (94.2%) | 93.9% |
| Yes | 113 (7.4%) | 6.0% | 460 (5.8%) | 6.1% |
| Missing | 1 | 0 | ||
| Transfusion of plasma | ||||
| No | 1486 (97.8%) | 98.5% | 7829 (98.7%) | 98.5% |
| Yes | 34 (2.2%) | 1.5% | 107 (1.4%) | 1.5% |
| Missing | 1 | 0 | ||
| Transfusion of platelets | ||||
| No | 1501 (98.8%) | 99.4% | 7891 (99.4%) | 99.3% |
| Yes | 19 (1.3%) | 0.6% | 45 (0.6%) | 0.7% |
| Missing | 1 | 0 | ||
Data are presented as n (%), mean ± SD or median [range]. ENT, Ear nose and throat; TUG, Timed Up and Go test.
Thirty patients that received clonidine and 10 patients with missing data in the premedication variable are excluded from the table.
Percentages may not total 100 because of rounding.
Multimorbidity was defined as the presence of at least two of the assessed comorbidities.
Limited mobility was defined as Timed Up and Go test performed in more than 12 s.
Mini-Cog screening tool to detect cognitive impairment or dementia: 3 or less cognitive impairment according to Robinson et al.
Frailty was classified as present, if at least four of the following six markers were present: Mini-Cog total score of 3 or less points; albumin level of 33 g l−1 or less; >1 fall in the last 6 months; haematocrit level of less than 35%; preoperative functional status is partially dependent or totally dependent; and at least three comorbidities present (according to Robinson et al.14 and Oresanya et al.16).
Regional anaesthesia constitutes the epidural, spinal or other regional anaesthesia technique.
Combined anaesthesia is defined as a combination of at least two of the three categories: general anaesthesia, sedation or regional anaesthesia.
Inverse-propensity-score weighted mean.
Effective relative frequency defined as the proportion on the inverse-propensity-score weights for each category in the benzodiazepine and nonbenzodiazepine premedication groups.