Impaired Executive Function and Depression as Independent Risk Factors for Reported Delirium Symptoms: An Observational Cohort Study Over 8 Years

Associations Between Depression Symptom Burden and Delirium Risk: A Prospective Cohort Study

Background and Objectives

Delirium and depression are prevalent in aging. There is considerable clinical overlap, including shared symptoms and comorbid conditions, including Alzheimer's disease, functional decline, and mortality. Despite this, the long-term relationship between depression and delirium remains unclear. This study assessed the associations of depression symptom burden and its trajectory with delirium risk in a 12-year prospective study of older hospitalized individuals.

Research Design and Methods

A total of 319 141 UK Biobank participants between 2006 and 2010 (mean age 58 years [range 37-74, SD = 8], 54% women) reported frequency (0-3) of 4 depressive symptoms (mood, disinterest, tenseness, or lethargy) in the preceding 2 weeks prior to initial assessment visit and aggregated into a depressive symptom burden score (0-12). New-onset delirium was obtained from hospitalization records during 12 years of median follow-up. 40 451 (mean age 57 ± 8; range 40-74 years) had repeat assessment on average 8 years after their first visit. Cox proportional hazard models examined whether depression symptom burden and trajectory predicted incident delirium.

Results

A total of 5 753 (15 per 1 000) newly developed delirium during follow-up. Increased risk for delirium was seen for mild (aggregated scores 1-2, hazards ratio, HR = 1.16, [95% confidence interval (CI): 1.08-1.25], p < .001), modest (scores 3-5, 1.30 [CI: 1.19-1.43], p < .001), and severe (scores ≥ 5, 1.38 [CI: 1.24-1.55], p < .001) depressive symptoms, versus none in the fully adjusted model. These findings were independent of the number of hospitalizations and consistent across settings (eg, surgical, medical, or critical care) and specialty (eg, neuropsychiatric, cardiorespiratory, or other). Worsening depression symptoms (≥1 point increase), compared to no change/improved score, were associated with an additional 39% increased risk (1.39 [1.03-1.88], p = .03) independent of baseline depression burden. The association was strongest in those over 65 years at baseline (p for interaction <.001).

Discussion and Implications

Depression symptom burden and worsening trajectory predicted delirium risk during hospitalization. Increased awareness of subclinical depression symptoms may aid delirium prevention.

Trail making test B in postoperative delirium: a replication study

Background

The Trail Making Test B (TMT-B) is indicative of cognitive flexibility and several other cognitive domains. Previous studies suggest that it might be associated with the risk of developing postoperative delirium, but evidence is limited and conflicting. We therefore aimed to replicate the association of preoperative TMT-B results with postoperative delirium.

Methods

We included older adults (≥65 yr) scheduled for major surgery and without signs of dementia to participate in this binational two-centre longitudinal observational cohort study. Presurgical TMT-B scores were obtained. Delirium was assessed twice daily using validated instruments. Logistic regression was applied and the area under the receiver operating characteristic curve calculated to determine the predictive performance of TMT-B. We subsequently included covariates used in previous studies for consecutive sensitivity analyses. We further analysed the impact of outliers, missing or impaired data.

Results

Data from 841 patients were included and of those, 151 (18%) developed postoperative delirium. TMT-B scores were statistically significantly associated with the incidence of postoperative delirium {odds ratio per 10-s increment 1.06 (95% confidence interval [CI] 1.02-1.09), P=0.001}. The area under the receiver operating characteristic curve was 0.60 ([95% CI 0.55-0.64], P<0.001). The association persisted after removing 21 outliers (1.07 [95% CI 1.03-1.07], P<0.001). Impaired or missing TMT-B data (n=88) were also associated with postoperative delirium (odds ratio 2.74 [95% CI 1.71-4.35], P<0.001).

Conclusions

The TMT-B was associated with postoperative delirium, but its predictive performance as a stand-alone test was low. The TMT-B alone is not suitable to predict delirium in a clinical setting.

Clinical trial registration

NCT02265263. (https://clinicaltrials.gov/ct2/show/results/NCT02265263).

Cognitive Deficits in Executive and Language Functions Predict Postoperative Delirium

OBJECTIVES

Postoperative delirium (POD) remains the most common complication in older adults, with cognitive impairment being the main risk factor. Patients with mild cognitive impairment, in particular, have much to lose from delirium; despite this, their cognitive impairment might be clinically overlooked. Understanding which cognitive domains are particularly predictive in this regard may improve the sensitivity of preoperative testing and allow for a more targeted application of resource-intensive measures to prevent delirium in the perioperative period. The authors conducted this study with the aim of identifying the most indicative cognitive domains.

DESIGN

A secondary analysis of a randomized controlled trial.

SETTING

At a single center, the University Medical Centre Hamburg in Hamburg, Germany.

PARTICIPANTS

Patients ≥60 years without major neurocognitive disorders (dementia, Mini-Mental State Examination score ≤23) scheduled for cardiovascular surgery.

MEASUREMENTS AND MAIN RESULTS

Preoperative neuropsychologic testing and delirium screening were performed twice daily until postoperative day 5. A multiple logistic regression model was applied to determine the predictive ability of test performances for the development of delirium.

RESULTS

A total of 541 patients were included in the analysis; the delirium rate was 15.6%. After controlling for confounders, only low performance within the Trail Making Test B/A (odds ratio [OR] = 1.32; 95% CI: 1.05-1.66) and letter fluency (OR = 0.66; 95% CI: 0.45-0.96) predicted a particularly high risk for delirium development. The discriminative ability of the final multiple logistic regression model to predict POD had an area under the curve of 0.786.

CONCLUSIONS

Impairment in the cognitive domains of executive function and language skills associated with memory, inhibition, and access speed seem to be particularly associated with the development of delirium after surgery in adults ≥65 years of age without apparent preoperative neurocognitive impairment.

The relationship between major depression and delirium: A two-sample Mendelian randomization analysis

BACKGROUND

Major depression (MD) is a well-recognized risk factor for delirium. However, observational studies cannot provide direct evidence of causality between MD and delirium.

METHODS

This study explored the genetic causal association between MD and delirium using two-sample Mendelian randomization (MR). Genome-wide association study (GWAS) summary data for MD were obtained from the UK Biobank. GWAS summary data for delirium were obtained from the FinnGen Consortium. Inverse-variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode were used to perform the MR analysis. In addition, the Cochrane's Q test was used to detect heterogeneity in the MR results. Horizontal pleiotropy was detected using the MR-Egger intercept test and MR pleiotropy residual sum and outliers (MR-PRESSO) test. Leave-one-out analysis was used to investigate the sensitivity of this association.

RESULTS

The IVW method showed that MD was an independent risk factor for delirium (P = 0.013). Horizontal pleiotropy was unlikely to bias causality (P > 0.05), and no evidence of heterogeneity was found between the genetic variants (P > 0.05). Finally, a leave-one-out test showed that this association was stable and robust.

LIMITATIONS

All participants included in the GWAS were of European ancestry. Due to database limitations, the MR analysis did not conduct stratified analyses for different countries, ethnicities, or age groups.

CONCLUSION

We conducted a two-sample MR analysis and found the evidence of genetic causal association between MD and delirium.

Association between Older Age and Psychiatric Symptoms in a Population of Hospitalized Patients with COVID-19

Increased rates of anxiety and depression have been reported for older adults during the COVID-19 pandemic. However, little is known regarding the onset of mental health morbidity during the acute phase of the disease and the role of age as potential independent risk factor for psychiatric symptoms. The cross-sectional association between older age and psychiatric symptoms has been estimated in a sample of 130 patients hospitalized for COVID-19 during the first and second wave of the pandemic. Compared to younger patients, those who were 70 years of age or older resulted at a higher risk of psychiatric symptoms measured on the Brief Psychiatric Symptoms Rating Scale (BPRS) (adjusted (adj.) odds ratio (OR) 2.36, 95% confidence interval (CI) 1.05-5.30) and delirium (adj. OR 5.24, 95% CI 1.63-16.8)). No association was found between older age and depressive symptoms or anxiety. Age was associated with psychiatric symptoms independently of gender, marital status, history of psychiatric illness, severity of disease and cardiovascular morbidity. Older adults appear at high risk of developing psychiatric symptoms related to COVID-19 disease during hospital stay. Multidisciplinary preventive and therapeutic interventions should be implemented to reduce the risk of psychiatric morbidity and related adverse health care outcomes among older hospital inpatients with COVID-19.

Prospective Analysis Between Neutrophil-to-Lymphocyte Ratio on Admission and Development of Delirium Among Older Hospitalized Patients With COVID-19

Objective: To examine any prospective association between neutrophil-to-lymphocyte ratio (NLR) at hospital admission and subsequent delirium in older COVID-19 hospitalized patients comparing by sex and age groups. Methods: The sample consisted of 1,785 COVID-19 adult inpatients (minimum sample size required of 635 participants) admitted to a public general hospital in Madrid (Spain) between March 16th and April 15th, 2020. Variables were obtained from electronic health records. Binary logistic regression models were performed between baseline NLR and delirium adjusting for age, sex, medical comorbidity, current illness severity, serious mental illness history and use of chloroquine and dexamethasone. An NLR cut-off was identified, and stratified analyses were performed by age and sex. Also, another biomarker was tested as an exposure (the systemic immune-inflammation index -SII). Results: 55.3% of the patients were men, with a mean age of 66.8 years. Roughly 13% of the patients had delirium during hospitalization. NLR on admission predicted subsequent delirium development (adjusted OR = 1.02, 95 percent CI: 1.00-1.04, p = 0.024). Patients between 69 and 80 years with NLR values > 6.3 presented a twofold increased risk for delirium (p = 0.004). There were no sex differences in the association between baseline NLR and delirium (p > 0.05) nor SII predicted delirium development (p = 0.341). Conclusion: NLR is a good predictor of delirium during hospitalization, especially among older adults, independently of medical comorbidity, illness severity, and other covariates. Routine blood tests on admission might provide valuable information to guide the decision-making process to be followed with these especially vulnerable patients.