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Meta-Analysis
. 2018 Apr;33(4):500-509.
doi: 10.1007/s11606-017-4204-x. Epub 2018 Jan 26.

Identifying Older Adults at Risk of Delirium Following Elective Surgery: A Systematic Review and Meta-Analysis

Jennifer Watt  1   2 , Andrea C Tricco  3   4 , Catherine Talbot-Hamon  1 , Ba' Pham  3   5 , Patricia Rios  3 , Agnes Grudniewicz  6 , Camilla Wong  3 , Douglas Sinclair  3 , Sharon E Straus  7   8
Affiliations
Meta-Analysis

Identifying Older Adults at Risk of Delirium Following Elective Surgery: A Systematic Review and Meta-Analysis

Jennifer Watt et al. J Gen Intern Med. 2018 Apr.

Abstract

Background: Postoperative delirium is a common preventable complication experienced by older adults undergoing elective surgery. In this systematic review and meta-analysis, we identified prognostic factors associated with the risk of postoperative delirium among older adults undergoing elective surgery.

Methods: Medline, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, and AgeLine were searched for articles published between inception and April 21, 2016. A total of 5692 titles and abstracts were screened in duplicate for possible inclusion. Studies using any method for diagnosing delirium were eligible. Two reviewers independently completed all data extraction and quality assessments using the Cochrane Risk-of-Bias Tool for randomized controlled trials (RCTs) and the Newcastle-Ottawa Scale (NOS) for cohort studies. Random effects meta-analysis models were used to derive pooled effect estimates.

Results: Forty-one studies (9384 patients) reported delirium-related prognostic factors. Among our included studies, the pooled incidence of postoperative delirium was 18.4% (95% confidence interval [CI] 14.3-23.3%, number needed to follow [NNF] = 6). Geriatric syndromes were important predictors of delirium, namely history of delirium (odds ratio [OR] 6.4, 95% CI 2.2-17.9), frailty (OR 4.1, 95% CI 1.4-11.7), cognitive impairment (OR 2.7, 95% CI 1.9-3.8), impairment in activities of daily living (ADLs; OR 2.1, 95% CI 1.6-2.6), and impairment in instrumental activities of daily living (IADLs; OR 1.9, 95% CI 1.3-2.8). Potentially modifiable prognostic factors such as psychotropic medication use (OR 2.3, 95% CI 1.4-3.6) and smoking status (OR 1.8 95% CI 1.3-2.4) were also identified. Caregiver support was associated with lower odds of postoperative delirium (OR 0.69, 95% CI 0.52-0.91).

Discussion: Though caution must be used in interpreting meta-analyses of non-randomized studies due to the potential influence of unmeasured confounding, we identified potentially modifiable prognostic factors including frailty and psychotropic medication use that should be targeted to optimize care.

Keywords: delirium; elective surgery; older adults; perioperative medicine; prognostic factors.

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Conflict of interest statement

Prior Presentations

The contents of this manuscript have been presented three times: (1) 36th Annual Canadian Geriatrics Society Annual Scientific Meeting, (2) 2016 Society for General Internal Medicine Meeting, and (3) 2016 Institute of Health Policy, Management and Evaluation Annual Research Day.

Conflict of Interest

The authors declare no competing interests.

Data Availability

The full data set is available from the corresponding author upon reasonable request.

Figures

Figure 1
Figure 1
Study flow diagram outlining the number of studies 1) retrieved in our literature search, 2) excluded from our systematic review at each level of screening, and 3) included in our qualitative and quantitative synthesis of preoperative prognostic factors associated with developing postoperative delirium.
See this image and copyright information in PMC

References

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