Table 3. Association between delirium superimposed on dementia and 12-mo mortality in acutely ill older adults; 2009–2015 (n = 1,144 discharges/976 patients).
| Variable | 12-mo mortality, n (percent) | Bivariate hazard ratio (95% CI) | Adjusted hazard ratioa (95% CI) | Adjusted p-value |
|---|---|---|---|---|
| Delirium/dementia | ||||
| No delirium/dementia | 85 (16) | Ref. | Ref. | Ref. |
| Dementia only | 42 (26) | 1.75 (1.16–2.63) | 1.19 (0.79–1.78) | 0.399 |
| Delirium only | 53 (26) | 1.73 (1.21–2.47) | 1.05 (0.71–1.54) | 0.810 |
| Delirium superimposed on dementia | 92 (37) | 2.60 (1.91–3.55) | 1.15 (0.79–1.68) | 0.463 |
| Age (10-y increase)b | — | 1.32 (1.12–1.56) | 1.27 (1.05–1.54) | 0.012 |
| Sex | ||||
| Male | 113 (25) | Ref. | Ref. | Ref. |
| Female | 159 (23) | 0.90 (0.69–1.17) | 0.93 (0.68–1.26) | 0.632 |
| Marital status | ||||
| Married | 115 (26) | Ref. | Ref. | Ref. |
| Widowed | 126 (24) | 0.95 (0.31–0.91) | 0.77 (0.55–1.08) | 0.126 |
| Single | 15 (15) | 0.53 (0.73–1.25) | 0.54 (0.32–0.92) | 0.023 |
| Divorced/separated | 16 (22) | 0.81 (0.48–1.39) | 0.95 (0.54–1.67) | 0.846 |
| Referring unit | ||||
| Outpatient clinic | 98 (21) | Ref. | Ref. | Ref. |
| Emergency department | 140 (23) | 1.11 (0.86–1.45) | 0.90 (0.68–1.20) | 0.484 |
| Intensive care unit | 34 (40) | 2.19 (1.46–3.29) | 1.83 (1.16–2.89) | 0.010 |
| Admission functional status (ADL points) | ||||
| 9–12 | 60 (13) | Ref. | Ref. | Ref. |
| 5–8 | 56 (21) | 1.62 (1.13–2.33) | 1.45 (1.00–2.10) | 0.050 |
| 0–4 | 156 (37) | 3.24 (2.37–4.43) | 2.48 (1.75–3.52) | <0.001 |
| Mini Nutritional Assessment | ||||
| Normal | 33 (17) | Ref. | Ref. | Ref. |
| Risk of malnutrition | 109 (21) | 1.28 (0.86–1.90) | 0.96 (0.64–1.45) | 0.847 |
| Malnutrition | 130 (31) | 2.07 (1.38–3.10) | 1.17 (0.74–1.83) | 0.501 |
| Polypharmacy | ||||
| No | 109 (25) | Ref. | Ref. | Ref. |
| Yes | 163 (21) | 0.87 (0.68–1.12) | 0.93 (0.70–1.23) | 0.603 |
| Cerebrovascular disease | ||||
| No | 203 (22) | Ref. | Ref. | Ref. |
| Yes | 69 (30) | 1.40 (1.05–1.86) | 1.25 (0.90–1.75) | 0.183 |
| Depression | ||||
| No | 211 (24) | Ref. | Ref. | Ref. |
| Yes | 61 (24) | 1.02 (0.76–1.37) | 1.05 (0.76–1.45) | 0.773 |
| Diabetes mellitus | ||||
| No | 191 (24) | Ref. | Ref. | Ref. |
| Yes | 81 (22) | 0.90 (0.68–1.19) | 0.94 (0.69–1.28) | 0.695 |
| Coronary disease | ||||
| No | 235 (25) | Ref. | Ref. | Ref. |
| Yes | 37 (19) | 0.73 (0.52–1.04) | 0.66 (0.44–1.00) | 0.048 |
| Heart failure | ||||
| No | 199 (24) | Ref. | Ref. | Ref. |
| Yes | 73 (24) | 0.98 (0.74–1.29) | 1.21 (0.87–1.67) | 0.259 |
| COPD | ||||
| No | 239 (24) | Ref. | Ref. | Ref. |
| Yes | 33 (25) | 1.07 (0.73–1.56) | 1.20 (0.82–1.75) | 0.356 |
| Cancer | ||||
| No | 247 (24) | Ref. | Ref. | Ref. |
| Yes | 25 (25) | 1.13 (0.74–1.74) | 1.18 (0.73–1.90) | 0.505 |
| Infection (at admission) | ||||
| No | 121 (19) | Ref. | Ref. | Ref. |
| Yes | 151 (30) | 1.59 (1.24–2.03) | 1.26 (0.95–1.67) | 0.108 |
| Heart rate (bpm) | ||||
| 60–100 | 240 (24) | Ref. | Ref. | Ref. |
| <60 | 11 (21) | 0.85 (0.47–1.54) | 1.01 (0.55–1.86) | 0.976 |
| ≥100 | 21 (29) | 1.25 (0.81–1.92) | 1.00 (0.61–1.65) | 0.987 |
| Mean arterial pressure (mm Hg) | ||||
| ≥90 | 136 (23) | Ref. | Ref. | Ref. |
| <90 | 136 (24) | 1.02 (0.80–1.29) | 1.05 (0.82–1.34) | 0.681 |
| Albumin (g/l) | — | 0.70 (0.58–0.83) | 0.87 (0.71–1.07) | 0.186 |
| GFR (ml/min) | ||||
| ≥60 | 127 (22) | Ref. | Ref. | Ref. |
| 30–59 | 101 (25) | 1.21 (0.93–1.57) | 1.42 (1.07–1.87) | 0.015 |
| <30 | 44 (28) | 1.39 (0.99–1.96) | 1.58 (1.07–2.34) | 0.023 |
| Urea (mmol/l) | ||||
| <3.3 | 210 (23) | Ref. | Ref. | Ref. |
| ≥3.3 | 62 (26) | 1.14 (0.86–1.51) | 0.76 (0.54–1.06) | 0.111 |
| Leucocytes (103 cells/mm3) | ||||
| <11 | 210 (23) | Ref. | Ref. | Ref. |
| ≥11 | 62 (27) | 1.20 (0.91–1.60) | 0.98 (0.72–1.31) | 0.870 |
| C-reactive protein (nmol/l) | ||||
| ≤476 | 153 (21) | Ref. | Ref. | Ref. |
| >476 | 119 (29) | 1.53 (1.20–1.95) | 1.34 (1.03–1.72) | 0.027 |
aCox proportional hazards model adjusted for all the variables included in the table.
bAge was analyzed as a continuous variable, and results indicate estimates for each additional decade of life.
ADL, activities of daily living; bpm, beats per minute; COPD, chronic obstructive pulmonary disease; GFR, glomerular filtration rate; Ref., referent category.