Table 1

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 factorDelirium
N=95
No delirium
N=213
ORp ValueAdjusted ORAdjusted p value
Demographic factors
 Age >75 years851493.65 (1.78 to 7.48)0.0004 
 Female sex501180.89 (0.55 to 1.45)0.650.77 (0.46 to 1.28)0.31
Medical history
 Dementia26252.62 (1.42 to 4.85)0.00212.08 (1.10 to 3.93)0.024
Falls45472.89 (1.72 to 4.87)<0.00012.47 (1.45 to 4.22)0.0009
 TIA/stroke30391.89 (1.09 to 3.30)0.0251.64 (0.93 to 2.90)0.088
 Depression22341.56 (0.85 to 2.85)0.151.60 (0.86 to 2.97)0.14
 Other psychiatric history4140.57 (0.18 to 1.79)0.340.67 (0.21 to 2.14)0.50
 Visual/hearing impairment16241.48 (0.74 to 2.93)0.271.06 (0.52 to 2.18)0.87
 Charlson score >312251.00 (0.48 to 2.09)1.000.95 (0.45 to 2.03)0.90
 Medications >3761551.12 (0.60 to 2.07)0.730.98 (0.52 to 1.85)0.94
 Medications >733790.80 (0.48 to 1.34)0.400.74 (0.44 to 1.26)0.27
Previous dependency
Care home/care package43413.19 (1.88 to 5.42)<0.00012.58 (1.48 to 4.48)0.0008
 Care home/community Hospital20133.82 (1.81 to 8.06)0.00052.88 (1.33 to 6.25)0.0075
Clinical parameters
 Low cognitive score56515.34 (2.73 to 10.47)<0.00015.00 (2.50 to 9.99)<0.0001
 Clinical dehydration32243.78 (2.07 to 6.92)<0.00013.53 (1.91 to 6.53)<0.0001
 Low oxygen saturation43661.72 (1.03 to 2.84)0.0371.66 (0.99 to 2.78)0.055
 Abnormal temperature25282.18 (1.19 to 4.01)0.0122.19 (1.17 to 4.09)0.014
 Abnormal WCC46612.18 (1.32 to 3.62)0.0032.06 (1.23 to 3.45)0.006
 Na <135 mm/L28561.17 (0.69 to 2.00)0.560.99 (0.47 to 2.10)0.99
 CRP >6 mm/L751352.17 (1.23 to 3.82)0.0082.04 (0.91 to 4.53)0.082
 BUN:Cr ratio28471.48 (0.85 to 2.55)0.161.41 (0.62 to 3.23)0.42
 SIRS >239522.17 (1.29 to 3.63)0.0031.98 (1.17 to 3.38)0.011
PSPS >6*31206.05 (2.89 to 12.67)<0.00015.56 (2.60 to 11.88)<0.0001
 MUST >0†12112.86 (1.09 to 7.46)0.0322.39 (0.89 to 6.43)0.083
Diagnosis
 Infection58514.93 (2.92 to 8.31)<0.00014.88 (2.85 to 8.36)<0.0001
 Cardiac9410.43 (0.20 to 0.92)0.0310.37 (0.17 to 0.81)0.013
 Stroke681.70 (0.57 to 5.03)0.341.94 (0.64 to 5.90)0.24
 Other261170.29 (0.17 to 0.50)<0.00010.30 (0.17 to 0.51)<0.0001
During admission
 Urinary incontinence44344.19 (2.42 to 7.26)<0.00013.76 (2.15 to 6.58)<0.0001
 Faecal incontinence28203.79 (2.00 to 7.19)<0.00013.49 (1.81 to 6.73)0.0002
 Bedbound34224.51 (2.45 to 8.31)<0.00014.21 (2.26 to 7.86)<0.0001
 Sleep deprivation26193.64 (1.89 to 7.00)0.00013.46 (1.78 to 6.74)0.0003
 Constipation19261.66 (0.86 to 3.18)0.131.40 (0.72 to 2.73)0.33
 Falls1054.63 (1.53 to 13.95)0.00654.55 (1.47 to 14.05)0.008
 CT brain scanning21232.19 (1.14 to 4.20)0.0182.49 (1.26 to 4.89)0.008
 Urinary catheter insertion27135.67 (2.77 to 11.64)<0.00015.08 (2.44 to 10.54)<0.0001
Outcome
 Stay >7 days52583.22 (1.94 to 5.35)<0.00012.82 (1.68 to 4.75)<0.0001
 New placement16143.13 (1.45 to 6.77)0.0042.95 (1.35 to 6.45)0.007
 Increased care26292.66 (1.44 to 4.90)0.0022.56 (1.37 to 4.76)0.003
 Death during admission1374.67 (1.80 to 12.11)0.0024.56 (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.