Risk factors for preoperative and postoperative delirium in elderly patients with hip fracture.
OBJECTIVE
To evaluate risk factors for preoperative and postoperative delirium.


METHODS
Prospective cohort study.


METHODS
Departments of orthopedic surgery in two Norwegian hospitals.


METHODS
Three hundred sixty-four patients with and without cognitive impairment, aged 65 and older.


METHODS
Patients were screened daily for delirium using the Confusion Assessment Method. Established risk factors and risk factors regarded as clinically important according to expert opinion were explored in univariate analyses. Variables associated with the outcomes (P<.05) were entered into multivariate logistic regression models.


RESULTS
Delirium was present in 50 of 237 (21.1%) assessable patients preoperatively, whereas 68 of 187 (36.4%) patients developed delirium postoperatively (incident delirium). Multivariate logistic regression identified four risk factors for preoperative delirium: cognitive impairment (adjusted odds ratio (AOR)=4.7, 95% confidence interval (CI)=1.9-11.3), indoor injury (AOR=3.6, 95% CI=1.1-12.2), fever (AOR=3.4, 95% CI=1.5-7.7), and preoperative waiting time (AOR=1.05, 95% CI=1.0-1.1 per hour). Cognitive impairment (AOR=2.9, 95% CI=1.4-6.2), indoor injury (AOR=2.9, 95% CI=1.1-6.3), and body mass index (BMI) less than 20.0 (AOR=2.9, 95% CI=1.3-6.7) were independent and statistically significant risk factors for postoperative delirium.


CONCLUSIONS
Time from admission to operation is a risk factor for preoperative delirium, whereas low BMI is an important risk factor for postoperative delirium in hip fracture patients. Cognitive impairment and indoor injury are independent risk factors for preoperative and postoperative delirium.
Juliebø
Vibeke
V
Department of Geriatric Medicine, Nursing Unit, Ullevaal University Hospital, Oslo, Norway. vibeke.juliebo@medisin.uio.no
Bjøro
Karen
K
Krogseth
Maria
M
Skovlund
Eva
E
Ranhoff
Anette H
AH
Wyller
Torgeir Bruun
TB
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003693:Delirium / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006620:Hip Fractures / Q000150:complications* / Q000601:surgery; D006801:Humans; D016015:Logistic Models; D008297:Male; D009664:Norway / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013997:Time Factors