Factors associated with any delirium in patients aged ≥65 years (OR and p values shown unadjusted and adjusted for age), bold values are those significant at the p=0.001 level
| Risk factor | Delirium N=95 | No delirium N=213 | OR | p Value | Adjusted OR | Adjusted p value |
|---|---|---|---|---|---|---|
| Demographic factors | ||||||
| Age >75 years | 85 | 149 | 3.65 (1.78 to 7.48) | 0.0004 | ||
| Female sex | 50 | 118 | 0.89 (0.55 to 1.45) | 0.65 | 0.77 (0.46 to 1.28) | 0.31 |
| Medical history | ||||||
| Dementia | 26 | 25 | 2.62 (1.42 to 4.85) | 0.0021 | 2.08 (1.10 to 3.93) | 0.024 |
| Falls | 45 | 47 | 2.89 (1.72 to 4.87) | <0.0001 | 2.47 (1.45 to 4.22) | 0.0009 |
| TIA/stroke | 30 | 39 | 1.89 (1.09 to 3.30) | 0.025 | 1.64 (0.93 to 2.90) | 0.088 |
| Depression | 22 | 34 | 1.56 (0.85 to 2.85) | 0.15 | 1.60 (0.86 to 2.97) | 0.14 |
| Other psychiatric history | 4 | 14 | 0.57 (0.18 to 1.79) | 0.34 | 0.67 (0.21 to 2.14) | 0.50 |
| Visual/hearing impairment | 16 | 24 | 1.48 (0.74 to 2.93) | 0.27 | 1.06 (0.52 to 2.18) | 0.87 |
| Charlson score >3 | 12 | 25 | 1.00 (0.48 to 2.09) | 1.00 | 0.95 (0.45 to 2.03) | 0.90 |
| Medications >3 | 76 | 155 | 1.12 (0.60 to 2.07) | 0.73 | 0.98 (0.52 to 1.85) | 0.94 |
| Medications >7 | 33 | 79 | 0.80 (0.48 to 1.34) | 0.40 | 0.74 (0.44 to 1.26) | 0.27 |
| Previous dependency | ||||||
| Care home/care package | 43 | 41 | 3.19 (1.88 to 5.42) | <0.0001 | 2.58 (1.48 to 4.48) | 0.0008 |
| Care home/community Hospital | 20 | 13 | 3.82 (1.81 to 8.06) | 0.0005 | 2.88 (1.33 to 6.25) | 0.0075 |
| Clinical parameters | ||||||
| Low cognitive score | 56 | 51 | 5.34 (2.73 to 10.47) | <0.0001 | 5.00 (2.50 to 9.99) | <0.0001 |
| Clinical dehydration | 32 | 24 | 3.78 (2.07 to 6.92) | <0.0001 | 3.53 (1.91 to 6.53) | <0.0001 |
| Low oxygen saturation | 43 | 66 | 1.72 (1.03 to 2.84) | 0.037 | 1.66 (0.99 to 2.78) | 0.055 |
| Abnormal temperature | 25 | 28 | 2.18 (1.19 to 4.01) | 0.012 | 2.19 (1.17 to 4.09) | 0.014 |
| Abnormal WCC | 46 | 61 | 2.18 (1.32 to 3.62) | 0.003 | 2.06 (1.23 to 3.45) | 0.006 |
| Na <135 mm/L | 28 | 56 | 1.17 (0.69 to 2.00) | 0.56 | 0.99 (0.47 to 2.10) | 0.99 |
| CRP >6 mm/L | 75 | 135 | 2.17 (1.23 to 3.82) | 0.008 | 2.04 (0.91 to 4.53) | 0.082 |
| BUN:Cr ratio | 28 | 47 | 1.48 (0.85 to 2.55) | 0.16 | 1.41 (0.62 to 3.23) | 0.42 |
| SIRS >2 | 39 | 52 | 2.17 (1.29 to 3.63) | 0.003 | 1.98 (1.17 to 3.38) | 0.011 |
| PSPS >6* | 31 | 20 | 6.05 (2.89 to 12.67) | <0.0001 | 5.56 (2.60 to 11.88) | <0.0001 |
| MUST >0† | 12 | 11 | 2.86 (1.09 to 7.46) | 0.032 | 2.39 (0.89 to 6.43) | 0.083 |
| Diagnosis | ||||||
| Infection | 58 | 51 | 4.93 (2.92 to 8.31) | <0.0001 | 4.88 (2.85 to 8.36) | <0.0001 |
| Cardiac | 9 | 41 | 0.43 (0.20 to 0.92) | 0.031 | 0.37 (0.17 to 0.81) | 0.013 |
| Stroke | 6 | 8 | 1.70 (0.57 to 5.03) | 0.34 | 1.94 (0.64 to 5.90) | 0.24 |
| Other | 26 | 117 | 0.29 (0.17 to 0.50) | <0.0001 | 0.30 (0.17 to 0.51) | <0.0001 |
| During admission | ||||||
| Urinary incontinence | 44 | 34 | 4.19 (2.42 to 7.26) | <0.0001 | 3.76 (2.15 to 6.58) | <0.0001 |
| Faecal incontinence | 28 | 20 | 3.79 (2.00 to 7.19) | <0.0001 | 3.49 (1.81 to 6.73) | 0.0002 |
| Bedbound | 34 | 22 | 4.51 (2.45 to 8.31) | <0.0001 | 4.21 (2.26 to 7.86) | <0.0001 |
| Sleep deprivation | 26 | 19 | 3.64 (1.89 to 7.00) | 0.0001 | 3.46 (1.78 to 6.74) | 0.0003 |
| Constipation | 19 | 26 | 1.66 (0.86 to 3.18) | 0.13 | 1.40 (0.72 to 2.73) | 0.33 |
| Falls | 10 | 5 | 4.63 (1.53 to 13.95) | 0.0065 | 4.55 (1.47 to 14.05) | 0.008 |
| CT brain scanning | 21 | 23 | 2.19 (1.14 to 4.20) | 0.018 | 2.49 (1.26 to 4.89) | 0.008 |
| Urinary catheter insertion | 27 | 13 | 5.67 (2.77 to 11.64) | <0.0001 | 5.08 (2.44 to 10.54) | <0.0001 |
| Outcome | ||||||
| Stay >7 days | 52 | 58 | 3.22 (1.94 to 5.35) | <0.0001 | 2.82 (1.68 to 4.75) | <0.0001 |
| New placement | 16 | 14 | 3.13 (1.45 to 6.77) | 0.004 | 2.95 (1.35 to 6.45) | 0.007 |
| Increased care | 26 | 29 | 2.66 (1.44 to 4.90) | 0.002 | 2.56 (1.37 to 4.76) | 0.003 |
| Death during admission | 13 | 7 | 4.67 (1.80 to 12.11) | 0.002 | 4.56 (1.71 to 12.17) | 0.003 |
*Missing total n=146.
†Missing total n=201.
Abnormal temperature, temperature >38°C or <36°C; abnormal WCC (white cell count), <4×109 or >12×109 cells per litre; Comm Hosp, community hospital; Low cognitive score, AMTS <9 or MMSE <24; low oxygen saturation, <95% on air;.
BUN, blood urea nitrogen; CRP, C reactive protein; MMSE, Mini-Mental State Examination; MUST, Malnutrition Universal Screening Tool; PSPS, Pressure Score Prediction Score; SIRS, systemic inflammatory response syndrome; TIA, transient ischaemic attack.