Table 5. Risk factors for incident delirium in patients with IQCODE ≥3.44, n = 158.
| Characteristic | No incident delirium | Incident delirium | Univariate models | Intermediate multivariate models | Final multivariate models | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| N = 81 (51%) | N = 77 (49%) | OR | 95% CI | P-valuea | OR | 95% CI | OR | 95% CI | p-valuea | |
| Background data | ||||||||||
| Age > 82 years, n/N (%) | 48/81 (59) | 62/77 (81) | 2.8 | 1.4–5.8 | 0.005 | 2.9 | 1.4–6.2 | 3.2 | 1.5–6.8 | 0.003 |
| NEADL < 45 points, n/N (%) | 61/81(75) | 67/76 (88) | 2.4 | 1.0–5.8 | 0.042 | 2.3 | 0.9–5.6 | 2.6 | 1.0–6.5 | 0.04 |
| BMI < 20.0 kg/m2, n/N (%) | 11/70 (16) | 16/67 (24) | 1.7 | 0.7–4.0 | 0.284 | |||||
| Time admission to surgery > 24 hours, n/N (%) | 28/79 (35) | 22/77 (29) | 0.7 | 0.4–1.4 | 0.394 | |||||
| Admission and preoperative data | ||||||||||
| ASA group III, IV or V, n/N (%) | 46/78 (59) | 47/74 (64) | 1.2 | 0.6–2.3 | 0.619 | |||||
| CRP > 10 mg/L, n/N (%) | 38/81 (47) | 26/76 (34) | 0.6 | 0.3–1.1 | 0.143 | |||||
| MAP at admission, mmHg, median (IQR) | 105 (92–119) | 105 (92–116) | 0.718 | |||||||
| HR at admission, bpm, median (IQR) | 80 (70–89) | 78 (68–96) | 0.720 | |||||||
| Per- and postoperative data | ||||||||||
| Type of anaesthesia | 0.207 | |||||||||
| General anaesthesia | 1/78 (1) | 4/76 (5) | ||||||||
| Spinal or epidural anaesthesia | 77/78 (99) | 72/76 (95) | ||||||||
| Duration of anaesthesia, in quartiles | 0.878 | |||||||||
| Q1 | 21/77 (27) | 18 /77 (23) | ||||||||
| Q2 | 20/77 (26) | 19/77 (25) | 1.1 | |||||||
| Q3 | 19/77 (25) | 19/77 (25) | 1.2 | |||||||
| Q4 | 17/77 (22) | 21/77 (27) | 1.4 | |||||||
| Being in Q4 vs Q1- Q3 | 17/77 (22) | 21/77 (27) | 1.3 | 0.6–2.8 | 0.575 | |||||
| Received benzodiazepine iv perioperatively, n/N (%) | 23/81 (28) | 38/77 (50) | 2.5 | 1.3–4.7 | 0.009 | 2.5 | 1.3–4.7 | 2.8 | 1.4–5.7 | 0.004 |
| Lowest MAP during anaesthesia, mmHg, median (IQR) | 65 (55–82) | 67 (62–75) | 0.450 | |||||||
| Difference in MAP from admission to lowest value during anaesthesia | 0.191 | |||||||||
| ≤ 30 mmHg, n/N (%) | 35/79 (44) | 29/76 (38) | ||||||||
| 31–40 mmHg, n/N (%) | 9/79 (11) | 18/76 (24) | 2.4 | |||||||
| 41–50 mmHg, n/N (%) | 11/79 (14) | 12/76 (16) | 1.3 | |||||||
| > 50 mmHg, n/N (%) | 24/79 (30) | 17/76 (22) | 0.9 | |||||||
| Pressor used during surgery, n/N (%) | 41/80 (51) | 30/77 (39) | 0.6 | 0.3–1.1 | 0.149 | |||||
| MAP postoperatively, mmHg, median (IQR) | 90 (75–96) | 89 (78–93) | 0.915 | |||||||
| HR postoperatively, beats per minute | 0.609 | |||||||||
| < 66 bpm, n/N (%) | 14/80 (18) | 10/76 (13) | ||||||||
| 66–75 bpm, n/N (%) | 18/80 (23) | 21/76 (28) | ||||||||
| 76–85 bpm, n/N (%) | 17/80 (21) | 14/76 (18) | ||||||||
| 86–95 bpm, n/N (%) | 13/80 (16) | 18/76 (24) | ||||||||
| > 95 bpm, n/N (%) | 18/80 (23) | 13/76 (17) | ||||||||
| SpO2% postoperatively, median (IQR) | 96 (94–98) | 97 (95–98) | 0.246 | |||||||
| Recevied blood transfusion during stay, n/N (%) | 38/81 (47) | 40/77 (52) | 0.8 | 0.4–1.5 | 0.633 | |||||
| Received ≥ 2 blood transfusions (SAG units), n/N (%) | 35/81 (43) | 32/77 (42) | 0.9 | 0.5–1.8 | 0.873 | |||||
The intermediate multivariate models consist of variables from the same main category (Background, Admission, Per- and Postoperative), and variables that turned out to be significant in these analyses were candidates for the final model.
IQCODE = Informant Questionnaire in Cognitive Decline in the Elderly; IQR = Interquartile range; NEADL = Nottingham Extended Activities of Daily Living; BMI = Body Mass Index; ASA = American Society of Anaesthesiologists; CRP = C -reactive protein; MAP = Mean Arterial Pressure; HR = Heart Rate; bpm = beats per minute
Missing data (N) for several variables: NEADL: N = 1, BMI: N = 21, Time to surgery: N = 2, ASA group: N = 6, CRP: N = 1, Type of anaesthesia: N = 4, Duration of anaesthesia: N = 4, Difference in MAP from admission to lowest value during anaesthesia: N = 3, Pressor used during surgery: N = 1, HR postoperatively: N = 2.
a Mann-Whitney tests for skewed continuous variables, p-values are 2-tailed. Logistic regression for categorical and ordinal variables.