Table 2.
Prediction Cohort: Independent Risk Factors for Delirium
| Risk Factor | Delirium Mean (SD) n/N (%) (n=63) |
No Delirium Mean (SD) n/N (%) (n=59) |
Crude p-values | Risk Ratio (95%CI)* | Entered into stepwise model |
|---|---|---|---|---|---|
| Mean Age (years) | 75.8 (6.5) | 73.5 (5.9) | .04 | 1.2 (0.9, 1.6)* | Yes |
| Female sex | 17 (27%) | 8 (14%) | .07 | 1.4 (1.0, 2.0) | Yes |
| White | 61 (97%) | 59 (100%) | .17 | ||
| Education | |||||
| >High School | 27 (43%) | 32 (55%) | .39 | Referent | |
| High School | 26 (41%) | 18 (31%) | 1.3 (0.9, 1.9) | ||
| <High School | 10 (16%) | 8 (14%) | 1.2 (0.7, 2.0) | ||
| Unmarried | 23 (37%) | 15 (24%) | .11 | 1.8 (0.9, 1.9) | |
| Tobacco Exposure | |||||
| None | 16 (27%) | 13 (24%) | .30 | Referent | |
| 1-30 pack-years | 28 (47%) | 20 (37%) | 1.1 (0,7, 1.6) | ||
| >=30 pack years | 15 (25%) | 21 (39%) | 0.8 (0.5, 1.3) | ||
| Alcohol Use | 28 (47%) | 38 (69%) | .02 | 0.6 (0.4, 0.9) | Yes |
| Mean BMI | 27.3 (5.7) | 29.4 (5.3) | .04 | 0.8 (0.6, 1.1)* | Yes |
| Hypertension | 51 (84%) | 48 (81%) | .75 | 1.1 (0.7, 1.8) | |
| Hyperlipidemia | 44 (72%) | 40 (68%) | .60 | 1.1 (0.7, 1.7) | |
| Diabetes | 28 (46%) | 28 (50%) | .86 | 1.0 (0.7, 1.4) | |
| Stroke/TIA | 19 (31%) | 7 (12%) | .01 | 1.6 (1.2, 2.3) | Yes |
| Cancer history | 3 (5%) | 6 (10%) | .28 | 0.6 (0.2, 1.6) | |
| Geriatric Depression Scale | 4.0 (3.3) | 2.6 (2.6) | .02 | 1.2 (1.0, 1.5)* | Yes |
| Instrumental Activities of Daily Living <21 | 33 (55%) | 24 (43%) | .19 | 1.2 (0.9, 1.8) | |
| Activities of Daily Living <18 | 7 (12%) | 3 (5%) | .23 | 1.4 (0.9, 2.2) | |
| ASA Class† 4 | 49 (80%) | 48 (81%) | .89 | 0.9 (0.6, 1.5) | |
| Mini Mental State Examination | 26.1 (2.9) | 27.7 (2.1) | <.001 | 0.8 (0.6, 1.0)* | Yes |
| Abnormal Albumin‡ | 22 (43%) | 11 (25%) | .06 | 1.4 (1.0, 2.0) | Yes |
| Hematocrit (%) | 36.5 (4.7) | 37.4 (4.2) | .25 | 0.9 (0.7, 1.2) | |
| Abnormal Laboratory Values§ | 13 (21%) | 11 (19%) | .86 | 1.0 (0.7, 1.6) | |
| Urea nitrogen : creatinine ≥18 | 43 (70%) | 38 (67%) | .65 | 1.0 (0.7, 1.5) | |
| Urgent Surgery | 52 (83%) | 44 (75%) | .28 | 1.3 (0.8, 2.1) | |
| Valve Surgery (±CABG) | 9 (14%) | 10 (17%) | .69 | 0.9 (0.5, 1.5) |
*
For continuous variables, the risk ratio is expressed as the risk per standard deviation increase
†
ASA-American Society of Anesthesiology;
‡
Abnormal Albumin ≤3.5 or ≥4.5g/dL
§
Abnormal electrolytes values: sodium <135 or >154(mg/dL); glucose <60 or >200(mg/dL); white blood cell count <3.0 or >20(×1000/mcL)
‖
CABG-Coronary Artery Bypass Graft