The incidence of delirium associated with orthopedic surgery: a meta-analytic review

• Published in: International psychogeriatrics Vol. 19; no. 2; pp. 197 - 214
• Main Authors: Bruce, Angela J., Ritchie, Craig W., Blizard, Robert, Lai, Rosalind, Raven, Peter
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.04.2007; Elsevier Inc
• Subjects: Aged; Biological and medical sciences; Bone surgery; Cognition Disorders - epidemiology; Delirium; Delirium - diagnosis; Delirium - epidemiology; Delirium - psychology; Fractures; Geriatrics; Hip Fractures - epidemiology; Hip Fractures - surgery; Hip joint; Humans; Incidence; Medical sciences; Meta-analysis; Orthopedic Procedures - psychology; Orthopedic Procedures - statistics & numerical data; orthopedic surgery; Orthopedics; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; review; Studies; Systematic review; meta-analysis; incidence; review; delirium; orthopedic surgery; Human; Delirium; Review; Epidemiology; Organic mental disorder; Incidence; Metaanalysis; Orthopedic surgery; Treatment; Elderly; Mental confusion; Public health
• ISSN: 1041-6102; 1741-203X
• DOI: 10.1017/S104161020600425X

Background: The aim of this study was to perform a systematic review and meta-analysis of the literature regarding the incidence of delirium following orthopedic surgery. Methods: Relevant papers were sourced from online databases and gray literature. Included studies used a validated diagnostic method to measure the incidence of delirium in a prospective sample of adult/elderly orthopedic patients. Data were subject to meta-analysis after stratification by type of surgery (elective v. emergency) and inclusion/exclusion of pre-existing cognitive impairment. A funnel plot assessed for publication bias. Results: 26 publications reported an incidence of postoperative delirium of 4–53.3% in hip fracture samples and 3.6–28.3% in elective samples. Significant heterogeneity was evident, and this persisted despite stratification. Hip fracture was associated with a higher risk of delirium than elective surgery both when the cognitively impaired were included in the sample (random effects pooled estimate = 21.7% [95% CI = 14.6–28.8] vs. 12.1% [95% CI = 9.6–14.6]), and when the cognitively impaired were excluded (random effects pooled estimate = 25% [95% CI = 15.7–34.7] vs. 8.8% [95% CI = 4.1–13.6]). The funnel plot showed a deficit of small studies showing low risk and large studies showing high risk. In eight hip fracture studies, the proportion of delirium cases with a preoperative onset ranged from 34 to 92%. Conclusions: Delirium occurs more commonly with hip fracture than elective surgery, and frequently has a preoperative onset when associated with trauma. Recommendations are made with the aim of standardizing future research in order to further explore and reduce the heterogeneity and possible publication bias observed.