A Novel Approach to Monitoring Cognitive Adverse Events for Interventional Studies Involving Advanced Dementia Patients: Insights From the Electroconvulsive Therapy for Agitation in Dementia Study

OBJECTIVE

To develop an individualized method for detecting cognitive adverse events (CAEs) in the context of an ongoing trial of electroconvulsive therapy for refractory agitation and aggression for advanced dementia (ECT-AD study).

METHODS

Literature search aimed at identifying (a) cognitive measures appropriate for patients with advanced dementia, (b) functional scales to use as a proxy for cognitive status in patients with floor effects on baseline cognitive testing, and (c) statistical approaches for defining a CAE, to develop CAEs monitoring plan specifically for the ECT-AD study.

RESULTS

Using the Severe Impairment Battery-8 (SIB-8), baseline floor effects are defined as a score of ≤5/16. For patients without floor effects, a decline of ≥6 points is considered a CAE. For patients with floor effects, a decline of ≥30 points from baseline on the Barthel Index is considered a CAE. These values were derived using the standard deviation index (SDI) approach to measuring reliable change.

CONCLUSIONS

The proposed plan accounts for practical and statistical challenges in detecting CAEs in patients with advanced dementia. While this protocol was developed in the context of the ECT-AD study, the general approach can potentially be applied to other interventional neuropsychiatric studies that carry the risk of CAEs in patients with advanced dementia.

Successful aging after elective surgery II: Study cohort description

BACKGROUND

The Successful Aging after Elective Surgery (SAGES) II Study was designed to examine the relationship between delirium and Alzheimer's disease and related dementias (AD/ADRD), by capturing novel fluid biomarkers, neuroimaging markers, and neurophysiological measurements. The goal of this paper is to provide the first complete description of the enrolled cohort, which details the baseline characteristics and data completion. We also describe the study modifications necessitated by the COVID-19 pandemic, and lay the foundation for future work using this cohort.

METHODS

SAGES II is a prospective observational cohort study of community-dwelling adults age 65 and older undergoing major non-cardiac surgery. Participants were assessed preoperatively, throughout hospitalization, and at 1, 2, 6, 12, and 18 months following discharge to assess cognitive and physical functioning. Since participants were enrolled throughout the COVID-19 pandemic, procedural modifications were designed to reduce missing data and allow for high data quality.

RESULTS

About 420 participants were enrolled with a mean (standard deviation) age of 73.4 (5.6) years, including 14% minority participants. Eighty-eight percent of participants had either total knee or hip replacements; the most common surgery was total knee replacement with 210 participants (50%). Despite the challenges posed by the COVID-19 pandemic, which required the use of novel procedures such as video assessments, there were minimal missing interviews during hospitalization and up to 1-month follow-up; nearly 90% of enrolled participants completed interviews through 6-month follow-up.

CONCLUSION

While there are many longitudinal studies of older adults, this study is unique in measuring health outcomes following surgery, along with risk factors for delirium through the application of novel biomarkers-including fluid (plasma and cerebrospinal fluid), imaging, and electrophysiological markers. This paper is the first to describe the characteristics of this unique cohort and the data collected, enabling future work using this novel and important resource.

Biomarkers of neurodegeneration and neural injury as potential predictors for delirium

OBJECTIVES

Determine if biomarkers of Alzheimer's disease and neural injury may play a role in the prediction of delirium risk.

METHODS

In a cohort of older adults who underwent elective surgery, delirium case-no delirium control pairs (N = 70, or 35 matched pairs) were matched by age, sex and vascular comorbidities. Biomarkers from CSF and plasma samples collected prior to surgery, including amyloid beta (Aβ)42 , Aβ40 , total (t)-Tau, phosphorylated (p)-Tau181 , neurofilament-light (NfL), and glial fibrillary acid protein (GFAP) were measured in cerebrospinal fluid (CSF) and plasma using sandwich enzyme-linked immunosorbent assays (ELISAs) or ultrasensitive single molecule array (Simoa) immunoassays.

RESULTS

Plasma GFAP correlated significantly with CSF GFAP and both plasma and CSF GFAP values were nearly two-fold higher in delirium cases. The median paired difference between delirium case and control without delirium for plasma GFAP was not significant (p = 0.074) but higher levels were associated with a greater risk for delirium (odds ratio 1.52, 95% confidence interval 0.85, 2.72 per standard deviation increase in plasma GFAP concentration) in this small study. No matched pair differences or associations with delirium were observed for NfL, p-Tau 181, Aβ40 and Aβ42 .

CONCLUSIONS

These preliminary findings suggest that plasma GFAP, a marker of astroglial activation, may be worth further investigation as a predictive risk marker for delirium.

Association of Loneliness With Change in Physical and Emotional Health of Older Adults During the COVID-19 Shutdown

OBJECTIVES

To examine factors influencing loneliness and the effect of loneliness on physical and emotional health, in the context of the COVID-19 pandemic.

DESIGN

Prospective, observational cohort.

SETTING

Community-dwelling participants.

PARTICIPANTS

Older adults (n = 238) enrolled in a longitudinal study.

MEASUREMENTS

Interviews were completed July-December 2020. Loneliness was measured with the UCLA 3-item loneliness scale. Data including age, marriage, education, cognitive functioning, functional impairment, vision or hearing impairment, depression, anxiety, medical comorbidity, social network size, technology use, and activity engagement were collected. Health outcomes included self-rated health, and physical and mental composites from the 12-item Short Form Survey. Physical function was measured by a PROMIS-scaled composite score.

RESULTS

Thirty-nine (16.4%) participants reported loneliness. Vulnerability factors for loneliness included age (RR = 1.08, 95% CI 1.02-1.14); impairment with instrumental activities of daily living (RR = 2.08, 95% CI 1.14-3.80); vision impairment (RR = 2.09, 95% CI 1.10-3.97); depression (RR = 1.34, 95% CI 1.25-1.43); and anxiety (RR = 1.92, 95% CI 1.55-2.39). Significant resilience factors included high cognitive functioning (RR = 0.88, 95% CI 0.83-0.94); large social network size (RR = 0.92, 95% CI 0.88-0.96); technology use (RR = 0.81, 95% CI 0.73-0.90); and social and physical activity engagement (RR = 0.91, 95% CI 0.85-0.98). Interaction analyses showed that larger social network size moderated the effect of loneliness on physical function (protective interaction effect, RR = 0.64, 95% CI 0.15-1.13, p <.01), and activity engagement moderated the effect of loneliness on mental health (protective interaction effect, RR = 0.65, 95% CI 0.25-1.05, p <.001).

CONCLUSIONS

Resilience factors may mitigate the adverse health outcomes associated with loneliness. Interventions to enhance resilience may help to diminish the detrimental effects of loneliness and hold great importance for vulnerable older adults.

Comparison of the frailty index and frailty phenotype and their associations with postoperative delirium incidence and severity

BACKGROUND

Recent studies have reported an association between presurgical frailty and postoperative delirium. However, it remains unclear whether the frailty-delirium relationship differs by measurement tool (e.g., frailty index vs. frailty phenotype) and whether frailty is associated with delirium, independent of preoperative cognition.

METHODS

We used the successful aging after elective surgery (SAGES) study, a prospective cohort of older adults age ≥70 undergoing major non-cardiac surgery (N = 505). Preoperative measurement of the modified mini-mental (3MS) test, frailty index and frailty phenotype were obtained. The confusion assessment method (CAM), supplemented by chart review, identified postoperative delirium. Delirium feature severity was measured by the sum of CAM-severity (CAM-S) scores. Generalized linear models were used to determine the relative risk of each frailty measure with delirium incidence and severity. Subsequent models adjusted for age, sex, surgery type, Charlson comorbidity index, and 3MS.

RESULTS

On average, patients were 76.7 years old (standard deviation 5.22), 58.8% of women. For the frailty index, the incidence of delirium was 14% in robust, 17% in prefrail, and 31% in frail patients (p < 0.001). For the frailty phenotype, delirium incidence was 13% in robust, 21% in prefrail, and 27% in frail patients (p = 0.016). Frailty index, but not phenotype, was independently associated with delirium after adjustment for comorbidities (relative risk [RR] 2.13, 95% confidence interval [CI] 1.23-3.70; RR 1.61, 95% CI 0.77-3.37, respectively). Both frailty measures were associated with delirium feature severity. After adjustment for preoperative cognition, only the frailty index was associated with delirium incidence; neither index nor phenotype was associated with delirium feature severity.

CONCLUSION

Both the frailty index and phenotype were associated with the development of postoperative delirium. The index showed stronger associations that remained significant after adjusting for baseline comorbidities and preoperative cognition. Measuring frailty prior to surgery can assist in identifying patients at risk for postoperative delirium.

Clinicians' Perceptions of a Modified Hospital Elder Life Program for Delirium Prevention During COVID-19

The Hospital Elder Life Program (HELP) is a multicomponent delirium prevention program targeting delirium risk factors of cognitive impairment, vision and hearing impairment, malnutrition and dehydration, immobility, sleep deprivation, and medications. We created a modified and extended version of the program, HELP-ME, deployable under COVID-19 conditions, for example, patient isolation and restricted staff and volunteer roles. We explored perceptions of interdisciplinary clinicians who implemented HELP-ME to inform its development and testing. Qualitative descriptive study of HELP-ME among older adults on medical and surgical services during the COVID-19 pandemic. HELP-ME staff at 4 pilot sites across the United States who implemented HELP-ME.We held five 1-hour video focus groups (5-16 participants/group) to review specific intervention protocols and the overall program. We asked participants open-endedly about positive and challenging aspects of protocol implementation. Groups were recorded and transcribed. We used directed content analysis to analyze data. Participants identified general, technology-related, and protocol-specific positive and challenging aspects of the program. Overarching themes included the need for enhanced customization and standardization of protocols, need for increased volunteer staffing, digital access to family members, patient technological literacy and comfort, variation in the feasibility of remote delivery among intervention protocols, and preference for a hybrid program model. Participants offered related recommendations. Participants felt that HELP-ME was successfully implemented, with some modifications needed to address limitations of remote implementation. A hybrid model combining remote and in-person aspects was recommended as the preferred option.

Caffeine, Postoperative Delirium And Change In Outcomes after Surgery (CAPACHINOS)-2: protocol for a randomised controlled trial

INTRODUCTION

Delirium is a major public health issue for surgical patients and their families because it is associated with increased mortality, cognitive and functional decline, prolonged hospital admission and increased healthcare expenditures. Based on preliminary data, this trial tests the hypothesis that intravenous caffeine, given postoperatively, will reduce the incidence of delirium in older adults after major non-cardiac surgery.

METHODS AND ANALYSIS

The CAffeine, Postoperative Delirium And CHange In Outcomes after Surgery-2 (CAPACHINOS-2) Trial is a single-centre, placebo-controlled, randomised clinical trial that will be conducted at Michigan Medicine. The trial will be quadruple-blinded, with clinicians, researchers, participants and analysts all masked to the intervention. The goal is to enrol 250 patients with a 1:1:1: allocation ratio: dextrose 5% in water placebo, caffeine 1.5 mg/kg and caffeine 3 mg/kg as a caffeine citrate infusion. The study drug will be administered intravenously during surgical closure and on the first two postoperative mornings. The primary outcome will be delirium, assessed via long-form Confusion Assessment Method. Secondary outcomes will include delirium severity, delirium duration, patient-reported outcomes and opioid consumption patterns. A substudy analysis will also be conducted with high-density electroencephalography (72-channel system) to identify neural abnormalities associated with delirium and Mild Cognitive Impairment at preoperative baseline.

ETHICS AND DISSEMINATION

This study was approved by the University of Michigan Medical School Institutional Review Board (HUM00218290). An independent data and safety monitoring board has also been empanelled and has approved the clinical trial protocol and related documents. Trial methodology and results will be disseminated via clinical and scientific journals along with social and news media.

TRIAL REGISTRATION NUMBER

NCT05574400.

Six-Year Cognitive Trajectory in Older Adults Following Major Surgery and Delirium

Importance

The study results suggest that delirium is the most common postoperative complication in older adults and is associated with poor outcomes, including long-term cognitive decline and incident dementia.

Objective

To examine the patterns and pace of cognitive decline up to 72 months (6 years) in a cohort of older adults following delirium.

Design, Setting, and Participants

This was a prospective, observational cohort study with long-term follow-up including 560 community-dwelling older adults (older than 70 years) in the ongoing Successful Aging after Elective Surgery study that began in 2010. The data were analyzed from 2021 to 2022.

Exposure

Development of incident delirium following major elective surgery.

Main Outcomes and Measures

Delirium was assessed daily during hospitalization using the Confusion Assessment Method, which was supplemented with medical record review. Cognitive performance using a comprehensive battery of neuropsychological tests was assessed preoperatively and across multiple points postoperatively to 72 months of follow-up. We evaluated longitudinal cognitive change using a composite measure of neuropsychological performance called the general cognitive performance (GCP), which is scaled so that 10 points on the GCP is equivalent to 1 population SD. Retest effects were adjusted using cognitive test results in a nonsurgical comparison group.

Results

The 560 participants (326 women [58%]; mean [SD] age, 76.7 [5.2] years) provided a total of 2637 person-years of follow-up. One hundred thirty-four participants (24%) developed postoperative delirium. Cognitive change following surgery was complex: we found evidence for differences in acute, post-short-term, intermediate, and longer-term change from the time of surgery that were associated with the development of postoperative delirium. Long-term cognitive change, which was adjusted for practice and recovery effects, occurred at a pace of about -1.0 GCP units (95% CI, -1.1 to -0.9) per year (about 0.10 population SD units per year). Participants with delirium showed significantly faster long-term cognitive change with an additional -0.4 GCP units (95% CI, -0.1 to -0.7) or -1.4 units per year (about 0.14 population SD units per year).

Conclusions and Relevance

This cohort study found that delirium was associated with a 40% acceleration in the slope of cognitive decline out to 72 months following elective surgery. Because this is an observational study, we cannot be sure whether delirium directly causes subsequent cognitive decline, or whether patients with preclinical brain disease are more likely to develop delirium. Future research is needed to understand the causal pathway between delirium and cognitive decline.

One-year Medicare costs associated with delirium in older hospitalized patients with and without Alzheimer's disease dementia and related disorders

INTRODUCTION

One-year health-care costs associated with delirium in older hospitalized patients with and without Alzheimer's disease and related dementias (ADRD) have not been examined previously.

METHODS

Medicare costs were determined prospectively at discharge, and at 30, 90, and 365 days in a cohort (n = 311) of older adults after hospital admission.

RESULTS

Seventy-six (24%) patients had ADRD and were more likely to develop delirium (51% vs. 24%, P < 0.001) and die within 1 year (38% vs. 21%, P = 0.002). In ADRD patients with versus without delirium, adjusted mean difference in costs associated with delirium were $34,828; most of the excess costs were incurred between 90 and 365 days (P = 0.03). In non-ADRD patients, delirium was associated with increased costs at all timepoints. Excess costs associated with delirium in ADRD patients increased progressively over 1 year, whereas in non-ADRD patients the increase was consistent across time periods.

DISCUSSION

Our findings highlight the complexity of health-care costs for ADRD patients who develop delirium, a potentially preventable source of expenditures.

HIGHLIGHTS

Novel examination of health-care costs of delirium in persons with and without Alzheimer's disease and related dementias (ADRD). Increased 1-year costs of $34,828 in ADRD patients with delirium (vs. without). Increased costs for delirium in ADRD occur later during the 365-day study period. For ADRD patients, cost differences between those with and without delirium increased over 1 year. For non-ADRD patients, the parallel cost differences were consistent over time.

Parental Education and Delirium Risk after Surgery in Older Adults

OBJECTIVES

Efforts to conceptualize risk factors for postoperative delirium in older adults have focused on the time proximate to the episode, but how early-life exposures influence delirium risk is poorly understood.

METHODS

An observational cohort of 547 patients aged 70+undergoing major non-cardiac surgery at two academic medical centers in Boston. Demographic characteristics, cognition, parental education, health, and participation in cognitively stimulating activities were assessed prior to surgery. Delirium incidence and severity were measured daily during hospitalization.

RESULTS

Higher paternal education was associated with significantly lower incidence of delirium (X2(1, N =547)=8.35, p <.001; odds ratio OR=.93, 95% CI, .87 to .98) and inversely associated with delirium severity (r(545)=-.13, p <.001). Higher maternal education was associated with lower delirium incidence but did not reach statistical significance. The effect of paternal education on delirium incidence was independent of the patient's education, estimated premorbid intelligence, medical comorbidities, neighborhood disadvantage, and participation in cognitively stimulating activities (X2(2, N =547)=31.22, p <.001).

CONCLUSIONS

Examining early-life exposures may yield unique insights into the risks and pathogenesis of delirium.

CLINICAL IMPLICATIONS

Evaluating long-term factors that increase vulnerability to delirium may improve our ability to calculate risk. It may guide clinical decision-making and inform pre- and post-operative recommendations.

Protocol for the electroencephalography guidance of anesthesia to alleviate geriatric syndromes (ENGAGES-Canada) study: A pragmatic, randomized clinical trial

Background:  There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery.  There is limited evidence in this regard for cardiac surgery.  A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death.  However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods:  The Electroe ncephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes ( ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites.  The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery.  One approach is based on current standard anesthetic practice and the other on electroencephalography guidance to reduce POD. In the guided arm, clinicians are encouraged to decrease anesthetic administration, primarily if there is electroencephalogram suppression and secondarily if the EEG index is lower than the manufacturers recommended value (bispectral index (BIS) or WAVcns below 40 or Patient State Index below 25).  The aim in the guided group is to administer the minimum concentration of anesthetic considered safe for individual patients.  The primary outcome of the study is the incidence of POD, detected using the confusion assessment method or the confusion assessment method for the intensive care unit; coupled with structured delirium chart review.  Secondary outcomes include unexpected intraoperative movement, awareness, length of intensive care unit and hospital stay, delirium severity and duration, quality of life, falls, and predictors and outcomes of perioperative distress and dissociation. Discussion:  The ENGAGES-Canada trial will help to clarify whether or not using the electroencephalogram to guide anesthetic administration during cardiac surgery decreases the incidence, severity, and duration of POD. Registration: ClinicalTrials.gov ( NCT02692300) 26/02/2016.

Protocol for the electroencephalography guidance of anesthesia to alleviate geriatric syndromes (ENGAGES-Canada) study: A pragmatic, randomized clinical trial

Background:  There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery.  There is limited evidence in this regard for cardiac surgery.  A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death.  However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods:  The Electroe ncephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes ( ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites.  The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery.  One approach is based on current standard anesthetic practice and the other on electroencephalography guidance to reduce POD. In the guided arm, clinicians are encouraged to decrease anesthetic administration, primarily if there is electroencephalogram suppression and secondarily if the EEG index is lower than the manufacturers recommended value (bispectral index (BIS) or WAVcns below 40 or Patient State Index below 25).  The aim in the guided group is to administer the minimum concentration of anesthetic considered safe for individual patients.  The primary outcome of the study is the incidence of POD, detected using the confusion assessment method or the confusion assessment method for the intensive care unit; coupled with structured delirium chart review.  Secondary outcomes include unexpected intraoperative movement, awareness, length of intensive care unit and hospital stay, delirium severity and duration, quality of life, falls, and predictors and outcomes of perioperative distress and dissociation. Discussion:  The ENGAGES-Canada trial will help to clarify whether or not using the electroencephalogram to guide anesthetic administration during cardiac surgery decreases the incidence, severity, and duration of POD. Registration: ClinicalTrials.gov ( NCT02692300) 26/02/2016.

Successful aging after elective surgery II: Study design and methods

BACKGROUND

The Successful Aging after Elective Surgery (SAGES) II study was designed to increase knowledge of the pathophysiology and linkages between delirium and dementia. We examine novel biomarkers potentially associated with delirium, including inflammation, Alzheimer's disease (AD) pathology and neurodegeneration, neuroimaging markers, and neurophysiologic markers. The goal of this paper is to describe the study design and methods for the SAGES II study.

METHODS

The SAGES II study is a 5-year prospective observational study of 400-420 community dwelling persons, aged 65 years and older, assessed prior to scheduled surgery and followed daily throughout hospitalization to observe for development of delirium and other clinical outcomes. Delirium is measured with the Confusion Assessment Method (CAM), long form, after cognitive testing. Cognitive function is measured with a detailed neuropsychologic test battery, summarized as a weighted composite, the General Cognitive Performance (GCP) score. Other key measures include magnetic resonance imaging (MRI), transcranial magnetic stimulation (TMS)/electroencephalography (EEG), and Amyloid positron emission tomography (PET) imaging. We describe the eligibility criteria, enrollment flow, timing of assessments, and variables collected at baseline and during repeated assessments at 1, 2, 6, 12, and 18 months.

RESULTS

This study describes the hospital and surgery-related variables, delirium, long-term cognitive decline, clinical outcomes, and novel biomarkers. In inter-rater reliability assessments, the CAM ratings (weighted kappa = 0.91, 95% confidence interval, CI = 0.74-1.0) in 50 paired assessments and GCP ratings (weighted kappa = 0.99, 95% CI 0.94-1.0) in 25 paired assessments. We describe procedures for data quality assurance and Covid-19 adaptations.

CONCLUSIONS

This complex study presents an innovative effort to advance our understanding of the inter-relationship between delirium and dementia via novel biomarkers, collected in the context of major surgery in older adults. Strengths include the integration of MRI, TMS/EEG, PET modalities, and high-quality longitudinal data.

Identifying Delirium in Persons With Moderate or Severe Dementia: Review of Challenges and an Illustrative Approach

Delirium and dementia are common causes of cognitive impairment among older adults, which often coexist. Delirium is associated with poor clinical outcomes, and is more frequent and more severe in patients with dementia. Identifying delirium in the presence of dementia, also described as delirium superimposed on dementia (DSD), is particularly challenging, as symptoms of delirium such as inattention, cognitive dysfunction, and altered level of consciousness, are also features of dementia. Because DSD is associated with poorer clinical outcomes than dementia alone, detecting delirium is important for reducing morbidity and mortality in this population. We review a number of delirium screening instruments that have shown promise for use in DSD, including the 4-DSD, combined Six Item Cognitive Impairment Test (6-CIT) and 4 'A's Test (4AT), Confusion Assessment Method (CAM), and the combined UB2 and 3D-CAM (UB-CAM). Each has advantages and disadvantages. We then describe the operationalization of a CAM-based approach in a current ECT in dementia project as an example of modifying an existing instrument for patients with moderate to severe dementia. Ultimately, any instrument modified will need to be validated against a standard clinical reference, in order to fully establish its sensitivity and specificity in the moderate to severe dementia population. Future work is greatly needed to advance the challenging area of accurate identification of delirium in moderate or severe dementia.

Association Between Perioperative Medication Use and Postoperative Delirium and Cognition in Older Adults Undergoing Elective Noncardiac Surgery

BACKGROUND

Postoperative delirium is frequent in older adults and is associated with postoperative neurocognitive disorder (PND). Studies evaluating perioperative medication use and delirium have generally evaluated medications in aggregate and been poorly controlled; the association between perioperative medication use and PND remains unclear. We sought to evaluate the association between medication use and postoperative delirium and PND in older adults undergoing major elective surgery.

METHODS

This is a secondary analysis of a prospective cohort study of adults ≥70 years without dementia undergoing major elective surgery. Patients were interviewed preoperatively to determine home medication use. Postoperatively, daily hospital use of 7 different medication classes listed in guidelines as risk factors for delirium was collected; administration before delirium was verified. While hospitalized, patients were assessed daily for delirium using the Confusion Assessment Method and a validated chart review method. Cognition was evaluated preoperatively and 1 month after surgery using a neurocognitive battery. The association between prehospital medication use and postoperative delirium was assessed using a generalized linear model with a log link function, controlling for age, sex, type of surgery, Charlson comorbidity index, and baseline cognition. The association between daily postoperative medication use (when class exposure ≥5%) and time to delirium was assessed using time-varying Cox models adjusted for age, sex, surgery type, Charlson comorbidity index, Acute Physiology and Chronic Health Evaluation (APACHE)-II score, and baseline cognition. Mediation analysis was utilized to evaluate the association between medication use, delirium, and cognitive change from baseline to 1 month.

RESULTS

Among 560 patients enrolled, 134 (24%) developed delirium during hospitalization. The multivariable analyses revealed no significant association between prehospital benzodiazepine (relative risk [RR], 1.44; 95% confidence interval [CI], 0.85-2.44), beta-blocker (RR, 1.38; 95% CI, 0.94-2.05), NSAID (RR, 1.12; 95% CI, 0.77-1.62), opioid (RR, 1.22; 95% CI, 0.82-1.82), or statin (RR, 1.34; 95% CI, 0.92-1.95) exposure and delirium. Postoperative hospital benzodiazepine use (adjusted hazard ratio [aHR], 3.23; 95% CI, 2.10-4.99) was associated with greater delirium. Neither postoperative hospital antipsychotic (aHR, 1.48; 95% CI, 0.74-2.94) nor opioid (aHR, 0.82; 95% CI, 0.62-1.11) use before delirium was associated with delirium. Antipsychotic use (either presurgery or postsurgery) was associated with a 0.34 point (standard error, 0.16) decrease in general cognitive performance at 1 month through its effect on delirium (P = .03), despite no total effect being observed.

CONCLUSIONS

Administration of benzodiazepines to older adults hospitalized after major surgery is associated with increased postoperative delirium. Association between inhospital, postoperative medication use and cognition at 1 month, independent of delirium, was not detected.

Psychometric Properties of a Delirium Severity Score for Older Adults and Association With Hospital and Posthospital Outcomes

IMPORTANCE

The ability to rate delirium severity is key to providing optimal care for older adults, and such ratings would allow clinicians to target patients with severe delirium and monitor response to treatment, recovery time, and prognosis; assess nursing burden and staffing needs; and, ultimately, provide more appropriate patient-centered care. Current delirium severity measures have been limited in their content, gradations, and measurement characteristics.

OBJECTIVE

To examine the internal consistency, reliability, and validity for clinical outcomes of the DEL-S delirium severity score, a measure of delirium severity that was developed using advanced psychometric approaches, analogous to those of the Patient-Reported Outcomes Measurement Information System initiative.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was conducted at a large academic medical center in Boston, Massachusetts. Adults aged 70 years or older who were admitted or transferred to medical or surgical services as either emergency or elective admissions were enrolled between October 20, 2015, and March 15, 2017, and were monitored for 1 year. Data analysis was performed from June 2020 to August 2021.

EXPOSURES

Delirium severity, measured by scores on the delirium severity score short-form (SF; 6 items, scored 0-13, with higher scores indicating more severe delirium) and long-form (LF; 17 items, scored 0-21), considered continuously and grouped into 5 categories.

MAIN OUTCOMES AND MEASURES

The primary outcomes were in-hospital outcomes, including length of stay and hospital costs, and posthospital (30, 90, and 365 days) outcomes, including death, health care costs, and rehospitalization.

RESULTS

The 352 participants had a median (IQR) age of 79.7 (74.6-85.5) years, 204 (58.0%) were women, and they were highly educated (median [IQR] duration of education, 14 [7-20] years). Patients in the highest delirium severity score SF group (scores 6-9) had a longer length of stay (13.3 vs 6.9 days; P for trend < .001), greater in-hospital costs ($57 700 vs $34 200), greater cumulative health care costs ($168 700 vs $106 500; P for trend = .01), and increased mortality at 1 year (50% vs 17%; P for trend = .02) compared with patients in the lowest delirium severity score SF group (score 0). Similar trends and significant findings were demonstrated for the delirium severity score LF.

CONCLUSIONS AND RELEVANCE

These findings suggest that the delirium severity score provides an approach for measuring delirium severity that is associated with adverse clinical outcomes in a direct exposure-response association and that the delirium severity score may help advance patient-centered care for delirium.

A structured ICA-based process for removing auditory evoked potentials

Transcranial magnetic stimulation (TMS)-evoked potentials (TEPs), recorded using electroencephalography (EEG), reflect a combination of TMS-induced cortical activity and multi-sensory responses to TMS. The auditory evoked potential (AEP) is a high-amplitude sensory potential-evoked by the "click" sound produced by every TMS pulse-that can dominate the TEP and obscure observation of other neural components. The AEP is peripherally evoked and therefore should not be stimulation site specific. We address the problem of disentangling the peripherally evoked AEP of the TEP from components evoked by cortical stimulation and ask whether removal of AEP enables more accurate isolation of TEP. We hypothesized that isolation of the AEP using Independent Components Analysis (ICA) would reveal features that are stimulation site specific and unique individual features. In order to improve the effectiveness of ICA for removal of AEP from the TEP, and thus more clearly separate the transcranial-evoked and non-specific TMS-modulated potentials, we merged sham and active TMS datasets representing multiple stimulation conditions, removed the resulting AEP component, and evaluated performance across different sham protocols and clinical populations using reduction in Global and Local Mean Field Power (GMFP/LMFP) and cosine similarity analysis. We show that removing AEPs significantly reduced GMFP and LMFP in the post-stimulation TEP (14 to 400 ms), driven by time windows consistent with the N100 and P200 temporal characteristics of AEPs. Cosine similarity analysis supports that removing AEPs reduces TEP similarity between subjects and reduces TEP similarity between stimulation conditions. Similarity is reduced most in a mid-latency window consistent with the N100 time-course, but nevertheless remains high in this time window. Residual TEP in this window has a time-course and topography unique from AEPs, which follow-up exploratory analyses suggest could be a modulation in the alpha band that is not stimulation site specific but is unique to individual subject. We show, using two datasets and two implementations of sham, evidence in cortical topography, TEP time-course, GMFP/LMFP and cosine similarity analyses that this procedure is effective and conservative in removing the AEP from TEP, and may thus better isolate TMS-evoked activity. We show TEP remaining in early, mid and late latencies. The early response is site and subject specific. Later response may be consistent with TMS-modulated alpha activity that is not site specific but is unique to the individual. TEP remaining after removal of AEP is unique and can provide insight into TMS-evoked potentials and other modulated oscillatory dynamics.

A framework of social determinants of health for delirium tailored to older adults

Delirium is a debilitating medical condition that disproportionately affects hospitalized older adults and is associated with adverse health outcomes, increased mortality, and high medical costs. Efforts to understand delirium risk in hospitalized older adults have focused on examining medical comorbidities, pre-existing cognitive deficits, and other clinical and demographic factors present in the period proximate to the hospitalization. The contribution of social determinants of health (SDOH), including social circumstances, environmental characteristics, and early-life exposures, referred as the social exposome, to delirium risk is poorly understood. Increased knowledge about the influence of SDOH will offer a more comprehensive understanding of factors that may increase vulnerability to delirium and poor outcomes. Clinically, these efforts can guide the development and implementation of holistic preventive strategies to improve clinical outcomes. We propose a SDOH framework for delirium adapted for older adults. We provide the definition, description, and rationale for the domains and variables in our proposed model.

Domains of delirium severity in Alzheimer's disease and related dementias

BACKGROUND

The ability to rate delirium severity is key to providing optimal care for persons with Alzheimer's Disease and Related Dementias (ADRD). Such ratings would allow clinicians to assess response to treatment, recovery time and prognosis, nursing burden and staffing needs, and to provide nuanced, appropriate patient-centered care. Given the lack of existing tools, we defined content domains for a new delirium severity instrument for use in individuals with mild to moderate ADRD, the DEL-S-AD.

METHODS

We built upon our previous study in which we created a content domain framework to inform development of a general delirium severity instrument, the DEL-S. We engaged a new expert panel to discuss issues of measurement in delirium and dementia and to determine which content domains from the prior framework were useful in characterizing delirium severity in ADRD. We also asked panelists to identify new domains. Our panel included eight interdisciplinary members with expertise in delirium and dementia. Panelists participated in two rounds of review followed by two surveys over 2 months.

RESULTS

Panelists endorsed the same content domains as for general delirium severity, including Cognitive, Level of Consciousness, Inattention, Psychiatric-Behavioral, Emotional Dysregulation, Psychomotor Features, and Functional; however, they excluded six of the original subdomains which they considered unhelpful in the context of ADRD: cognitive impairment; anxiety; fear/sense of unease; depression; gait/walking; and incontinence. Debated measurement challenges included assessment at one point in time versus over time, accounting for differences in clinical settings, and accurate assessment of symptoms related to delirium versus dementia.

CONCLUSIONS

By capturing a range of characteristics of delirium severity potentially present in patients with ADRD, a population that may already have attention, functional, and emotional changes at baseline, the DEL-S-AD provides a novel rating tool that will be useful for clinical and research purposes to improve patient care.

Evaluation of the 3-Minute Diagnostic Confusion Assessment Method for Identification of Postoperative Delirium in Older Patients

IMPORTANCE

Delirium is a common postoperative complication in older patients that often goes undetected and might lead to worse outcomes. The 3-Minute Diagnostic Confusion Assessment Method (3D-CAM) might be a practical tool for routine clinical diagnosis of delirium.

OBJECTIVE

To assess the 3D-CAM for detecting postoperative delirium compared with the long-form CAM used for research purposes.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of older patients enrolled in ongoing clinical trials between 2015 and 2018 was conducted at a single tertiary US hospital. Included participants were aged 60 years or older undergoing major elective surgical procedures that required at least a 2-day hospital stay. Data were analyzed between February and April 2019.

EXPOSURES

Surgical procedures of at least 2 hours in length requiring general anesthesia with planned extubation.

MAIN OUTCOMES AND MEASURES

Patients were concurrently assessed for delirium using the 3D-CAM assessment and the long-form CAM, scored based on a standardized cognitive assessment. Agreement between these 2 methods was tested using Cohen κ with repeated measures, a generalized linear mixed-effects model, and Bland-Altman analysis.

RESULTS

Sixteen raters conducted 471 concurrent CAM and 3D-CAM interviews including 299 patients (mean [SD] age, 69 [6.5] years), the majority of whom were men (152 [50.8%]), were White (263 [88.0%]), and had noncardiac operations (211 [70.6%]). Both instruments had good intraclass correlation (0.84 for the CAM and 0.98 for the 3D-CAM). Cohen κ demonstrated good overall agreement between the CAM and 3D-CAM (κ = 0.71; 95% CI, 0.58 to 0.83). According to the mixed-effects model, there was statistically significant disagreement between the 3D-CAM and CAM (estimated difference in fixed effect, -0.68; 95% CI, -1.32 to -0.05; P = .04). Bland-Altman analysis showed the probability of a delirium diagnosis with the 3D-CAM was more than twice the probability of a delirium diagnosis with the CAM (probability ratio, 2.78; 95% CI, 2.44 to 3.23).

CONCLUSIONS AND RELEVANCE

The 3D-CAM instrument demonstrated agreement with the long-form CAM and might provide a pragmatic and sensitive clinical tool for detecting postoperative delirium, with the caveat that the 3D-CAM might overdiagnose delirium.

Predictors of Caregiver Burden in Delirium: Patient and Caregiver Factors

The current study examined the association of patient factors, patient/caregiver relationships, and living arrangements with caregiver burden due to delirium. The sample included a subset (N = 207) of hospitalized medical and surgical patients (aged >70 years) enrolled in the Better Assessment of Illness Study and their care-givers. The majority of caregivers were female (57%) and married (43%), and 47% reported living with the patient. Delirium occurred in 22% of the sample, and delirium severity, pre-existing cognitive impairment, and impairment of any activities of daily living (ADL) were associated with higher caregiver burden. However, only the ADL impairment of needing assistance with transfers was independently significantly associated with higher burden (p < 0.01). Child, child-in-law, and other relatives living with or apart from the patient reported significantly higher caregiver burden compared to spouse/partners (p < 0.01), indicating caregiver relationship and living arrangement are associated with burden. Future studies should examine additional factors contributing to delirium burden. [Journal of Gerontological Nursing, 47(9), 32-39.].

Development and internal validation of a predictive model of cognitive decline 36 months following elective surgery

INTRODUCTION

Our goal was to determine if features of surgical patients, easily obtained from the medical chart or brief interview, could be used to predict those likely to experience more rapid cognitive decline following surgery.

METHODS

We analyzed data from an observational study of 560 older adults (≥70 years) without dementia undergoing major elective non-cardiac surgery. Cognitive decline was measured using change in a global composite over 2 to 36 months following surgery. Predictive features were identified as variables readily obtained from chart review or a brief patient assessment. We developed predictive models for cognitive decline (slope) and predicting dichotomized cognitive decline at a clinically determined cut.

RESULTS

In a hold-out testing set, the regularized regression predictive model achieved a root mean squared error (RMSE) of 0.146 and a model r-square (R2 ) of .31. Prediction of "rapid" decliners as a group achieved an area under the curve (AUC) of .75.

CONCLUSION

Some of our models could predict persons with increased risk for accelerated cognitive decline with greater accuracy than relying upon chance, and this result might be useful for stratification of surgical patients for inclusion in future clinical trials.

One-Year Medicare Costs Associated With Delirium in Older Patients Undergoing Major Elective Surgery

Importance

Delirium is a common, serious, and potentially preventable problem for older adults, associated with adverse outcomes. Coupled with its preventable nature, these adverse sequelae make delirium a significant public health concern; understanding its economic costs is important for policy makers and health care leaders to prioritize care.

Objective

To evaluate current 1-year health care costs attributable to postoperative delirium in older patients undergoing elective surgery.

Design, Setting, and Participants

This prospective cohort study included 497 patients from the Successful Aging after Elective Surgery (SAGES) study, an ongoing cohort study of older adults undergoing major elective surgery. Patients were enrolled from June 18, 2010, to August 8, 2013. Eligible patients were 70 years or older, English-speaking, able to communicate verbally, and scheduled to undergo major surgery at 1 of 2 Harvard-affiliated hospitals with an anticipated length of stay of at least 3 days. Eligible surgical procedures included total hip or knee replacement; lumbar, cervical, or sacral laminectomy; lower extremity arterial bypass surgery; open abdominal aortic aneurysm repair; and open or laparoscopic colectomy. Data were analyzed from October 15, 2019, to September 15, 2020.

Exposures

Major elective surgery and hospitalization.

Main Outcomes and Measures

Cumulative and period-specific costs (index hospitalization, 30-day, 90-day, and 1-year follow-up) were examined using Medicare claims and extensive clinical data. Total inflation-adjusted health care costs were determined using data from Medicare administrative claims files for the 2010 to 2014 period. Delirium was rated using the Confusion Assessment Method. We also examined whether increasing delirium severity was associated with higher cumulative and period-specific costs. Delirium severity was measured with the Confusion Assessment Method-Severity long form. Regression models were used to determine costs associated with delirium after adjusting for patient demographic and clinical characteristics.

Results

Of the 566 patients who were eligible for the study, a total of 497 patients (mean [SD] age, 76.8 [5.1] years; 281 women [57%]; 461 White participants [93%]) were enrolled after exclusion criteria were applied. During the index hospitalization, 122 patients (25%) developed postoperative delirium, whereas 375 (75%) did not. Patients with delirium had significantly higher unadjusted health care costs than patients without delirium (mean [SD] cost, $146 358 [$140 469] vs $94 609 [$80 648]). After adjusting for relevant confounders, the cumulative health care costs attributable to delirium were $44 291 (95% CI, $34 554-$56 673) per patient per year, with the majority of costs coming from the first 90 days: index hospitalization ($20 327), subsequent rehospitalizations ($27 797), and postacute rehabilitation stays ($2803). Health care costs increased directly and significantly with level of delirium severity (none-mild, $83 534; moderate, $99 756; severe, $140 008), suggesting an exposure-response relationship. The adjusted mean cumulative costs attributable to severe delirium were $56 474 (95% CI, $40 927-$77 440) per patient per year. Extrapolating nationally, the health care costs attributable to postoperative delirium were estimated at $32.9 billion (95% CI, $25.7 billion-$42.2 billion) per year.

Conclusions and Relevance

These findings suggest that the economic outcomes of delirium and severe delirium after elective surgery are substantial, rivaling costs associated with cardiovascular disease and diabetes. These results highlight the need for policy imperatives to address delirium as a large-scale public health issue.

Machine Learning to Develop and Internally Validate a Predictive Model for Post-operative Delirium in a Prospective, Observational Clinical Cohort Study of Older Surgical Patients

BACKGROUND

Our objective was to assess the performance of machine learning methods to predict post-operative delirium using a prospective clinical cohort.

METHODS

We analyzed data from an observational cohort study of 560 older adults (≥ 70 years) without dementia undergoing major elective non-cardiac surgery. Post-operative delirium was determined by the Confusion Assessment Method supplemented by a medical chart review (N = 134, 24%). Five machine learning algorithms and a standard stepwise logistic regression model were developed in a training sample (80% of participants) and evaluated in the remaining hold-out testing sample. We evaluated three overlapping feature sets, restricted to variables that are readily available or minimally burdensome to collect in clinical settings, including interview and medical record data. A large feature set included 71 potential predictors. A smaller set of 18 features was selected by an expert panel using a consensus process, and this smaller feature set was considered with and without a measure of pre-operative mental status.

RESULTS

The area under the receiver operating characteristic curve (AUC) was higher in the large feature set conditions (range of AUC, 0.62-0.71 across algorithms) versus the selected feature set conditions (AUC range, 0.53-0.57). The restricted feature set with mental status had intermediate AUC values (range, 0.53-0.68). In the full feature set condition, algorithms such as gradient boosting, cross-validated logistic regression, and neural network (AUC = 0.71, 95% CI 0.58-0.83) were comparable with a model developed using traditional stepwise logistic regression (AUC = 0.69, 95% CI 0.57-0.82). Calibration for all models and feature sets was poor.

CONCLUSIONS

We developed machine learning prediction models for post-operative delirium that performed better than chance and are comparable with traditional stepwise logistic regression. Delirium proved to be a phenotype that was difficult to predict with appreciable accuracy.

Neighborhood-Level Social Disadvantage and Risk of Delirium Following Major Surgery

BACKGROUND/OBJECTIVES

Delirium is a common postoperative complication associated with prolonged length of stay, hospital readmission, and premature mortality. We explored the association between neighborhood-level characteristics and delirium incidence and severity, and compared neighborhood- with individual-level indicators of socioeconomic status in predicting delirium incidence.

DESIGN

A prospective observational cohort of patients enrolled between June 18, 2010, and August 8, 2013. Baseline interviews were conducted before surgery, and delirium/delirium severity was evaluated daily during hospitalization. Research staff evaluating delirium were blinded to baseline cognitive status.

SETTING

Two academic medical centers in Boston, MA.

PARTICIPANTS

A total of 560 older adults, aged 70 years or older, undergoing major noncardiac surgery.

INTERVENTION

The Area Deprivation Index (ADI) was used to characterize each neighborhood's socioeconomic disadvantage.

MEASUREMENTS

Delirium was assessed using the Confusion Assessment Method (CAM) long form. Delirium severity was calculated using the highest value of CAM Severity score (CAM-S) occurring during daily hospital assessments (CAM-S Peak).

RESULTS

Residing in the most disadvantaged neighborhoods (ADI > 44) was associated with a higher risk of incident delirium (12/26; 46%), compared with the least disadvantaged neighborhoods (122/534; 23%) (risk ratio (RR) (95% confidence interval (CI)) = 2.0 (1.3-3.1). The CAM-S Peak score was significantly associated with ADI (Spearman rank correlation, ρ = 0.11; P = .009). Mean CAM-S Peak scores generally rose from 3.7 to 5.3 across levels of increasing neighborhood disadvantage. The RR (95% CI) values associated with individual-level markers of socioeconomic status and cultural background were: 1.2 (0.9-1.7) for education of 12 years or less; 1.3 (0.8-2.1) for non-White race; and 1.7 (1.1-2.6) for annual household income of less than $20,000. None of these individual-level markers exceeded the ADI in terms of effect size or significance for prediction of delirium risk.

CONCLUSIONS

Neighborhood-level makers of social disadvantage are associated with delirium incidence and severity, and demonstrated an exposure-response relationship. Future studies should consider contextual-level metrics, such as the ADI, as risk markers of social disadvantage that can help to guide delirium treatment and prevention.

Preoperative Depressive Symptoms Associated with Poor Functional Recovery after Surgery

BACKGROUND/OBJECTIVES

Depression screening and treatment for older adults are recommended in Age-Friendly Health Systems. Few studies have evaluated the association between depressive symptoms and postoperative functioning. We aimed to determine the association between varying levels of depressive symptoms in the preoperative setting with postoperative functional recovery.

DESIGN

Prospective cohort study.

SETTING

Two academic hospitals in Boston, Massachusetts.

PARTICIPANTS

Surgical patients aged 70 and older (N = 560).

MEASUREMENTS

Participants were assessed preoperatively and 1 year postoperatively. Preoperative evaluation included the 15-item short-form Geriatric Depression Scale (GDS). Results were categorized as low (GDS = 0-1), moderate (2-5), or high (6-15) symptom burden. Primary outcome was 1-year instrumental activities of daily living functional decline. Secondary outcomes included hospital stay longer than 5 days, discharge to post-acute care (PAC) facility, and readmission within 30 days.

RESULTS

Mean participant age was 76.6 ± 5 years, 58% were women, 81% underwent an orthopedic operation, 13% gastrointestinal, 6% vascular; 13% had functional decline at 1 year after their operation (by symptom burden: low = 5.5%; moderate = 14.8%, and high = 38.6%). After adjusting for age, sex, and comorbidity, those with moderate or high depressive symptoms demonstrated greater odds of functional decline at 1 year compared with those with a low symptom burden (moderate: adjusted odds ratio [AOR] = 2.7; 95% confidence interval [CI] = 1.3-5.3; high: AOR = 9.3; 95% CI = 4.2-20.6), discharge to PAC facility (moderate: AOR = 1.7; 95%CI = 1.2-2.6; high: AOR = 2.7; 95% CI = 1.4-5.1) but demonstrated no significant association with 30-day readmission or hospital length of stay longer than 5 days.

CONCLUSION

Greater burden of preoperative depressive symptoms is associated with increased likelihood of functional decline at 1 year after surgery and of discharge to PAC facility. Preoperative assessment of the burden of depressive symptoms in older adults undergoing elective surgery may be helpful in identifying patients at high risk of poor outcomes.

Detecting Delirium: A Systematic Review of Identification Instruments for Non-ICU Settings

BACKGROUND/OBJECTIVES

Delirium manifests clinically in varying ways across settings. More than 40 instruments currently exist for characterizing the different manifestations of delirium. We evaluated all delirium identification instruments according to their psychometric properties and frequency of citation in published research.

DESIGN

We conducted the systematic review by searching Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, Excerpta Medica Database (Embase), PsycINFO, PubMed, and Web of Science from January 1, 1974, to January 31, 2020, with the keywords "delirium" and "instruments," along with their known synonyms. We selected only systematic reviews, meta-analyses, or narrative literature reviews including multiple delirium identification instruments.

MEASUREMENTS

Two reviewers assessed the eligibility of articles and extracted data on all potential delirium identification instruments. Using the original publication on each instrument, the psychometric properties were examined using the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) framework.

RESULTS

Of 2,542 articles identified, 75 met eligibility criteria, yielding 30 different delirium identification instruments. A count of citations was determined using Scopus for the original publication for each instrument. Each instrument underwent methodological quality review of psychometric properties using COSMIN definitions. An expert panel categorized key domains for delirium identification based on criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III through DSM-5. Four instruments were notable for having at least two of three of the following: citation count of 200 or more, strong validation methodology in their original publication, and fulfillment of DSM-5 criteria. These were, alphabetically, Confusion Assessment Method, Delirium Observation Screening Scale, Delirium Rating Scale-Revised-98, and Memorial Delirium Assessment Scale.

CONCLUSION

Four commonly used and well-validated instruments can be recommended for clinical and research use. An important area for future investigation is to harmonize these measures to compare and combine studies on delirium.

Association of Plasma Neurofilament Light with Postoperative Delirium

OBJECTIVE

To examine the association of the plasma neuroaxonal injury markers neurofilament light (NfL), total tau, glial fibrillary acid protein, and ubiquitin carboxyl-terminal hydrolase L1 with delirium, delirium severity, and cognitive performance.

METHODS

Delirium case-no delirium control (n = 108) pairs were matched by age, sex, surgery type, cognition, and vascular comorbidities. Biomarkers were measured in plasma collected preoperatively (PREOP), and 2 days (POD2) and 30 days postoperatively (PO1MO) using Simoa technology (Quanterix, Lexington, MA). The Confusion Assessment Method (CAM) and CAM-S (Severity) were used to measure delirium and delirium severity, respectively. Cognitive function was measured with General Cognitive Performance (GCP) scores.

RESULTS

Delirium cases had higher NfL on POD2 and PO1MO (median matched pair difference = 16.2pg/ml and 13.6pg/ml, respectively; p < 0.05). Patients with PREOP and POD2 NfL in the highest quartile (Q4) had increased risk for incident delirium (adjusted odds ratio [OR] = 3.7 [95% confidence interval (CI) = 1.1-12.6] and 4.6 [95% CI = 1.2-18.2], respectively) and experienced more severe delirium, with sum CAM-S scores 7.8 points (95% CI = 1.6-14.0) and 9.3 points higher (95% CI = 3.2-15.5). At PO1MO, delirium cases had continued high NfL (adjusted OR = 9.7, 95% CI = 2.3-41.4), and those with Q4 NfL values showed a -2.3 point decline in GCP score (-2.3 points, 95% CI = -4.7 to -0.9).

INTERPRETATION

Patients with the highest PREOP or POD2 NfL levels were more likely to develop delirium. Elevated NfL at PO1MO was associated with delirium and greater cognitive decline. These findings suggest NfL may be useful as a predictive biomarker for delirium risk and long-term cognitive decline, and once confirmed would provide pathophysiological evidence for neuroaxonal injury following delirium. ANN NEUROL 2020;88:984-994.

Preoperative Cognitive Abnormality, Intraoperative Electroencephalogram Suppression, and Postoperative Delirium: A Mediation Analysis

BACKGROUND

Postoperative delirium is a common complication that hinders recovery after surgery. Intraoperative electroencephalogram suppression has been linked to postoperative delirium, but it is unknown if this relationship is causal or if electroencephalogram suppression is merely a marker of underlying cognitive abnormalities. The hypothesis of this study was that intraoperative electroencephalogram suppression mediates a nonzero portion of the effect between preoperative abnormal cognition and postoperative delirium.

METHODS

This is a prespecified secondary analysis of the Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) randomized trial, which enrolled patients age 60 yr or older undergoing surgery with general anesthesia at a single academic medical center between January 2015 and May 2018. Patients were randomized to electroencephalogram-guided anesthesia or usual care. Preoperative abnormal cognition was defined as a composite of previous delirium, Short Blessed Test cognitive score greater than 4 points, or Eight Item Interview to Differentiate Aging and Dementia score greater than 1 point. Duration of intraoperative electroencephalogram suppression was defined as number of minutes with suppression ratio greater than 1%. Postoperative delirium was detected via Confusion Assessment Method or chart review on postoperative days 1 to 5.

RESULTS

Among 1,113 patients, 430 patients showed evidence of preoperative abnormal cognition. These patients had an increased incidence of postoperative delirium (151 of 430 [35%] vs.123 of 683 [18%], P < 0.001). Of this 17.2% total effect size (99.5% CI, 9.3 to 25.1%), an absolute 2.4% (99.5% CI, 0.6 to 4.8%) was an indirect effect mediated by electroencephalogram suppression, while an absolute 14.8% (99.5% CI, 7.2 to 22.5%) was a direct effect of preoperative abnormal cognition. Randomization to electroencephalogram-guided anesthesia did not change the mediated effect size (P = 0.078 for moderation).

CONCLUSIONS

A small portion of the total effect of preoperative abnormal cognition on postoperative delirium was mediated by electroencephalogram suppression. Study precision was too low to determine if the intervention changed the mediated effect.

The Role of Inflammation after Surgery for Elders (RISE) study: Examination of [11C]PBR28 binding and exploration of its link to post-operative delirium

Major surgery is associated with a systemic inflammatory cascade that is thought, in some cases, to contribute to transient and/or sustained cognitive decline, possibly through neuroinflammatory mechanisms. However, the relationship between surgery, peripheral and central nervous system inflammation, and post-operative cognitive outcomes remains unclear in humans, primarily owing to limitations of in vivo biomarkers of neuroinflammation which vary in sensitivity, specificity, validity, and reliability. In the present study, [11C]PBR28 positron emission tomography, cerebrospinal fluid (CSF), and blood plasma biomarkers of inflammation were assessed pre-operatively and 1-month post-operatively in a cohort of patients (N = 36; 30 females; ≥70 years old) undergoing major orthopedic surgery under spinal anesthesia. Delirium incidence and severity were evaluated daily during hospitalization. Whole-brain voxel-wise and regions-of-interest analyses were performed to determine the magnitude and spatial extent of changes in [11C]PBR28 uptake following surgery. Results demonstrated that, compared with pre-operative baseline, [11C]PBR28 binding in the brain was globally downregulated at 1 month following major orthopedic surgery, possibly suggesting downregulation of the immune system of the brain. No significant relationship was identified between post-operative delirium and [11C]PBR28 binding, possibly due to a small number (n = 6) of delirium cases in the sample. Additionally, no significant relationships were identified between [11C]PBR28 binding and CSF/plasma biomarkers of inflammation. Collectively, these results contribute to the literature by demonstrating in a sizeable sample the effect of major surgery on neuroimmune activation and preliminary evidence identifying no apparent associations between [11C]PBR28 binding and fluid inflammatory markers or post-operative delirium.

Delirium Burden in Patients and Family Caregivers: Development and Testing of New Instruments

BACKGROUND AND OBJECTIVES

Delirium creates distinct emotional distress in patients and family caregivers, yet there are limited tools to assess the experience. Our objective was to develop separate patient and family caregiver delirium burden instruments and to test their content and construct validity.

RESEARCH DESIGN AND METHODS

Two hundred forty-seven patients and 213 family caregivers were selected from an ongoing prospective cohort of medical-surgical admissions aged ≥70 years old. New patient and family caregiver delirium burden instruments were developed and used to measure the subjective experiences of in-hospital delirium. Delirium and delirium severity were measured by the Confusion Assessment Method (CAM) and CAM-Severity (long form).

RESULTS

Both Delirium Burden (DEL-B) instruments consist of eight questions and are measured on a 0 - 40 point scale. Final questions had good clarity and relevancy, as rated by the expert panel, and good internal consistency (Cronbach's α = .82-.86). In the cohort validation, Patient DEL-B (DEL-B-P) was 5.1 points higher and Family Caregiver DEL-B (DEL-B-C) was 5.8 points higher, on average, for patients who developed delirium compared to those who did not (p < .001). Test-retest reliability of DEL-B-C at baseline and 1 month was strong (correlation = .73). Delirium severity was mildly-moderately correlated with DEL-B-P (correlation = .34) and DEL-B-C (correlation = .26), suggesting contribution of other factors.

DISCUSSION AND IMPLICATIONS

We created instruments to reliably measure and evaluate the burden of delirium for patients and their family caregivers. Although additional validation is indicated, these instruments provide a key first step toward measuring and improving the subjective experience of delirium for patients and their families.

Does Alzheimer's Disease and Related Dementias Modify Delirium Severity and Hospital Outcomes?

OBJECTIVES

We examined the association between delirium severity and outcomes of delirium among persons with and without Alzheimer's disease and related dementias (ADRD).

DESIGN

Prospective cohort study.

SETTING

Academic tertiary medical center.

PARTICIPANTS

A total of 352 medical and surgical patients.

MEASUREMENTS

Delirium incidence and severity were rated daily using the Confusion Assessment Method (CAM) and CAM-Severity (CAM-S) score during hospitalization. Severe delirium was defined as a CAM-S Short Form score in the highest tertile (3-7 points out of 7). ADRD status was determined by a clinical consensus process. Clinical outcomes included prolonged length of stay (>6 d), discharge to post-acute nursing facility, any decline in activities of daily living (ADLs) at 1 month from prehospital baseline, ongoing nursing facility stay, and mortality.

RESULTS

Patients with ADRD (n = 85 [24%]) had a significantly higher relative risk (RR) for incident delirium (RR = 2.31; 95% confidence interval [CI] = 1.64-3.28) and higher peak CAM-S scores (mean difference = 1.24 points; CI = .83-1.65; P < .001). Among patients with ADRD, severe delirium significantly increased the RR for nursing facility stay (RR = 2.22; CI = 1.05-4.69; P = .04) and increased the RR for mortality (RR = 2.10; CI = .89-4.98; P = .09). Among patients without ADRD, severe delirium was associated with a significantly increased risk for all poor outcomes except mortality including prolonged length of stay in the hospital (RR = 1.47; CI = 1.18-1.82) and discharge to a post-acute nursing facility (RR = 2.17; CI = 1.58-2.98) plus decline in ADLs (RR = 1.30; CI = 1.05-1.60) and nursing facility stay at 1 month (RR = 1.93; CI = 1.31-2.83).

CONCLUSION

Severe delirium is associated with increased risk for poor clinical outcomes in patients with and without ADRD. In both groups, severe delirium increased risk of nursing home placement. In patients with ADRD, delirium was more severe and associated with a trend toward increased mortality at 1 month. Although the increased risk remains substantial by RR, the study had limited power to examine the rarer outcome of death. J Am Geriatr Soc 68:1722-1730, 2020.

New Delirium Severity Indicators: Generation and Internal Validation in the Better Assessment of Illness (BASIL) Study

BACKGROUND

Delirium is a common and preventable geriatric syndrome. Moving beyond the binary classification of delirium present/absent, delirium severity represents a potentially important outcome for evaluating preventive and treatment interventions and tracking the course of patients. Although several delirium severity assessment tools currently exist, most have been developed in the absence of advanced measurement methodology and have not been evaluated with rigorous validation studies.

OBJECTIVE

We aimed to report our development of new delirium severity items and the results of item reduction and selection activities guided by psychometric analysis of data derived from a field study.

METHODS

Building on our literature review of delirium instruments and expert panel process to identify domains of delirium severity, we adapted items from existing delirium severity instruments and generated new items. We then fielded these items among a sample of 352 older hospitalized patients.

RESULTS

We used an expert panel process and psychometric data analysis techniques to narrow a set of 303 potential items to 17 items for use in a new delirium severity instrument. The 17-item set demonstrated good internal validity and favorable psychometric characteristics relative to comparator instruments, including the Confusion Assessment Method - Severity (CAM-S) score, the Delirium Rating Scale Revised 98, and the Memorial Delirium Assessment Scale.

CONCLUSION

We more fully conceptualized delirium severity and identified characteristics of an ideal delirium severity instrument. These characteristics include an instrument that is relatively quick to administer, is easy to use by raters with minimal training, and provides a severity rating with good content validity, high internal consistency reliability, and broad domain coverage across delirium symptoms. We anticipate these characteristics to be represented in the subsequent development of our final delirium severity instrument.

The Role of Inflammation after Surgery for Elders (RISE) study: Study design, procedures, and cohort profile

Introduction

The Role of Inflammation after Surgery for Elders study correlates novel inflammatory markers measured in blood, cerebrospinal fluid (CSF) assays, and [¹¹C]-PBR28 positron-emission tomography imaging.

Methods

This study involved a prospective cohort design with patients who underwent elective hip and knee arthroplasty under spinal anesthesia. Sixty-five adults participated with their family members. Inflammatory biomarker assays were measured preoperatively on day 1 and postoperatively at one month.

Results

On average, participants were 75 years old, and 72% were female. 54% underwent total knee arthroplasty, and 46% underwent total hip arthroplasty. The mean Modified Mini-Mental State (3MS) Examination score was 89.3; four patients (6%) scored ≤77 points. Plasma assays were completed in 63 (97%) participants, cerebrospinal fluid assays in 61 (94%), and PET imaging in 44 (68%).

Discussion

This complex study presents an innovative effort to correlate peripheral and central inflammatory biomarkers before and after major surgery in older adults. Strengths include collecting concurrent blood, cerebrospinal fluid, and positron-emission tomography with detailed clinical characterization of delirium, cognition, and functional status.

•

We describe the methodology of the Role of Inflammation after Surgery for Elders Study.

•

This is a prospective cohort of elective hip/knee arthroplasty patients 70 years or older.

•

We examine inflammation in blood, cerebrospinal fluid and positron emission tomography.

•

We collect novel biomarkers preoperatively and one-month postoperatively.

•

There is clinical characterization of delirium, cognition and functional status.

The Caregiver Burden of Delirium in Older Adults With Alzheimer Disease and Related Disorders

OBJECTIVES

To measure the burden of delirium in older adults with or without Alzheimer disease or related disorders (ADRDs).

DESIGN

Prospective, observational cohort.

SETTING

Inpatient hospital and study participants' homes.

PARTICIPANTS

A subset (n = 267) of older medical and surgical patients and their caregivers enrolled in the Better Assessment of Illness study.

MEASUREMENTS

Delirium burden was measured using the DEL-B instrument (range = 0-40, with higher scores indicating greater burden) in caregivers (DEL-B-C) and patients 1 month after hospitalization. Severity of cognitive impairment (Montreal Cognitive Assessment [MoCA]), delirium presence (Confusion Assessment Method [CAM]), and delirium severity (CAM-Severity [CAM-S]) were measured during hospitalization and at 1-month follow-up. ADRD diagnosis was determined by a clinical consensus process.

RESULTS

For patients with (n = 56) and without (n = 211) ADRD, both DEL-B instruments had good internal consistency. DEL-B-C scores had a median (interquartile range) among caregivers of patients with and without ADRD of 9 (5-15) and 5 (1-11), respectively (P < .05). If the patient developed delirium, caregivers experienced greater burden (β[delirium × ADRD] = -.29; P = .42), regardless of ADRD status. Further, caregiver burden was modestly correlated with patient MoCA scores (Spearman correlation coefficient, ρ = -0.18; P = .01). Patients with ADRD who developed delirium self-reported less burden than those without ADRD (β[delirium × ADRD] = -.67; P = .044). As with caregivers, delirium burden was modestly correlated with patient MoCA score (ρ = -0.18; P = .005) and correlated with the CAM-S in patients without ADRD (ρ = 0.38; P < .001) but not for patients with ADRD (ρ = -0.07; P = .61).

CONCLUSIONS

Delirium resulted in the same degree of increased caregiver burden regardless of whether a patient had ADRD, signifying delirium is equally stressful to caregivers, even among those with experience caring for someone with a chronic cognitive disorder. Delirium burden is only modestly associated with degree of cognitive impairment, suggesting that other aspects of delirium contribute to burden. J Am Geriatr Soc 67:2587-2592, 2019.

Use of an expert panel to identify domains and indicators of delirium severity

PURPOSE

Our purpose was to create a content domain framework for delirium severity to inform item development for a new instrument to measure delirium severity.

METHODS

We used an established, multi-stage instrument development process during which expert panelists discussed best approaches to measure delirium severity and identified related content domains. We conducted this work as part of the Better ASsessment of ILlness (BASIL) study, a prospective, observational study aimed at developing and testing measures of delirium severity. Our interdisciplinary expert panel consisted of twelve national delirium experts and four expert members of the core research group. Over a one-month period, experts participated in two rounds of review.

RESULTS

Experts recommended that the construct of delirium severity should reflect both the phenomena and the impact of delirium to create an accurate, patient-centered instrument useful to interdisciplinary clinicians and family caregivers. Final content domains were Cognitive, Level of consciousness, Inattention, Psychiatric-Behavioral, Emotional dysregulation, Psychomotor features, and Functional. Themes debated by experts included reconciling clinical geriatrics and psychiatric content, mapping symptoms to one specific domain, and accurate capture of unclear clinical presentations.

CONCLUSIONS

We believe this work represents the first application of instrument development science to delirium. The identified content domains are inclusive of various, wide-ranging domains of delirium severity and are reflective of a consistent framework that relates delirium severity to potential clinical outcomes. Our content domain framework provides a foundation for development of delirium severity instruments that can help improve care and quality of life for patients with delirium.

Perspectives on the Delirium Experience and Its Burden: Common Themes Among Older Patients, Their Family Caregivers, and Nurses

BACKGROUND AND OBJECTIVES

While there are qualitative studies examining the delirium-related experiences of patients, family caregivers, and nurses separately, little is known about common aspects of delirium burden among all three groups. We describe common delirium burdens from the perspectives of patients, family caregivers, and nurses.

RESEARCH DESIGN AND METHODS

We conducted semistructured qualitative interviews about delirium burden with 18 patients who had recently experienced a delirium episode, with 16 family caregivers, and with 15 nurses who routinely cared for patients with delirium. We recruited participants from a large, urban teaching hospital in Boston, Massachusetts. Interviews were recorded and transcribed. We used interpretive description as the approach to data analysis.

RESULTS

We identified three common burden themes of the delirium experience: Symptom Burden (Disorientation, Hallucinations/Delusions, Impaired Communication, Memory Problems, Personality Changes, Sleep Disturbances); Emotional Burden (Anger/Frustration, Emotional Distress, Fear, Guilt, Helplessness); and Situational Burden (Loss of Control, Lack of Attention, Lack of Knowledge, Lack of Resources, Safety Concerns, Unpredictability, Unpreparedness). These burdens arise from different sources among patients, family caregivers, and nurses, with markedly differing perspectives on the burden experience.

DISCUSSION AND IMPLICATIONS

Our findings advance the understanding of common burdens of the delirium experience for all groups and offer structure for instrument development and distinct interventions to address the burden of delirium as an individual or group experience. Our work reinforces that no one group experiences delirium in isolation. Delirium is a shared experience that will respond best to systemwide approaches to reduce associated burden.

Use of the confusion assessment method in multicentre delirium trials: training and standardisation

Background

Delirium occurs commonly in older adults and is associated with adverse outcomes. Multicentre clinical trials evaluating interventions to prevent delirium are needed. The Confusion Assessment Method (CAM) is a validated instrument for delirium detection. We hypothesised it would be possible for a large feasibility study to train a large number of research assistants, with varying experience levels, to conduct CAM assessments reliably in multiple hospital sites.

Methods

A standardised training programme was followed, incorporating structured training at a central location and at study sites. CAM practice sessions on both delirious and non-delirious patients by research assistants were conducted and, thereafter, there was ongoing inter-rater reliability assessment on the CAM between research assistant pairs at study sites. The setting was eight acute care hospitals in England and Wales. Participants were research assistants working on a multicentre feasibility study of delirium prevention. The measurement used was the Confusion Assessment Method.

Results

Thirty-seven research assistants were trained in CAM assessment and 33 returned training logs. The logs showed there was 100% overall agreement between research assistant pairs on 295 CAM assessments, of which 263 (89.2%) were negative for delirium and 32 (10.8%) were positive. In the course of the feasibility study, research assistants successfully completed 5065 (89.7%) of the 5645 expected CAM assessments, with minimal missing data.

Conclusion

Using the training methods described in this study, it is possible to achieve high quality delirium assessments for large numbers of patients with little missing data across geographically dispersed sites in multicentre studies. The standardisation of multisite delirium assessments is an important contribution to research methodology, and provides a much-needed advance for the field.

Trial registration

ISRCT ISRCTN01187372. Registered 13 March 2014.

Effect of Electroencephalography-Guided Anesthetic Administration on Postoperative Delirium Among Older Adults Undergoing Major Surgery: The ENGAGES Randomized Clinical Trial

IMPORTANCE

Intraoperative electroencephalogram (EEG) waveform suppression, often suggesting excessive general anesthesia, has been associated with postoperative delirium.

OBJECTIVE

To assess whether EEG-guided anesthetic administration decreases the incidence of postoperative delirium.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of 1232 adults aged 60 years and older undergoing major surgery and receiving general anesthesia at Barnes-Jewish Hospital in St Louis. Recruitment was from January 2015 to May 2018, with follow-up until July 2018.

INTERVENTIONS

Patients were randomized 1:1 (stratified by cardiac vs noncardiac surgery and positive vs negative recent fall history) to receive EEG-guided anesthetic administration (n = 614) or usual anesthetic care (n = 618).

MAIN OUTCOMES AND MEASURES

The primary outcome was incident delirium during postoperative days 1 through 5. Intraoperative measures included anesthetic concentration, EEG suppression, and hypotension. Adverse events included undesirable intraoperative movement, intraoperative awareness with recall, postoperative nausea and vomiting, medical complications, and death.

RESULTS

Of the 1232 randomized patients (median age, 69 years [range, 60 to 95]; 563 women [45.7%]), 1213 (98.5%) were assessed for the primary outcome. Delirium during postoperative days 1 to 5 occurred in 157 of 604 patients (26.0%) in the guided group and 140 of 609 patients (23.0%) in the usual care group (difference, 3.0% [95% CI, -2.0% to 8.0%]; P = .22). Median end-tidal volatile anesthetic concentration was significantly lower in the guided group than the usual care group (0.69 vs 0.80 minimum alveolar concentration; difference, -0.11 [95% CI, -0.13 to -0.10), and median cumulative time with EEG suppression was significantly less (7 vs 13 minutes; difference, -6.0 [95% CI, -9.9 to -2.1]). There was no significant difference between groups in the median cumulative time with mean arterial pressure below 60 mm Hg (7 vs 7 minutes; difference, 0.0 [95% CI, -1.7 to 1.7]). Undesirable movement occurred in 137 patients (22.3%) in the guided and 95 (15.4%) in the usual care group. No patients reported intraoperative awareness. Postoperative nausea and vomiting was reported in 48 patients (7.8%) in the guided and 55 patients (8.9%) in the usual care group. Serious adverse events were reported in 124 patients (20.2%) in the guided and 130 (21.0%) in the usual care group. Within 30 days of surgery, 4 patients (0.65%) in the guided group and 19 (3.07%) in the usual care group died.

CONCLUSIONS AND RELEVANCE

Among older adults undergoing major surgery, EEG-guided anesthetic administration, compared with usual care, did not decrease the incidence of postoperative delirium. This finding does not support the use of EEG-guided anesthetic administration for this indication.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02241655.

Assessment of Instruments for Measurement of Delirium Severity: A Systematic Review

Importance

Measurement of delirium severity has been recognized as highly important for tracking prognosis, monitoring response to treatment, and estimating burden of care for patients both during and after hospitalization. Rather than simply rating delirium as present or absent, the ability to quantify its severity would enable development and monitoring of more effective treatment approaches for the condition.

Objectives

To present a comprehensive review of delirium severity instruments, conduct a methodologic quality rating of the original validation study of the most commonly used instruments, and select a group of top-rated instruments.

Evidence Review

This systematic review was conducted using literature from Embase, PsycINFO, PubMed, Web of Science, and Cumulative Index to Nursing and Allied Health Literature, from January 1, 1974, through March 31, 2017, with the key words delirium, severity, tests, measures, and intensity. Inclusion criteria were original articles assessing delirium severity and using a delirium-specific severity instrument. Final listings of articles were supplemented with hand searches of reference listings to ensure completeness. At least 2 reviewers independently completed each step of the review process: article selection, data extraction, and methodologic quality assessment of relevant articles using a validated rating scale. All discrepancies between raters were resolved by consensus.

Findings

Of 9409 articles identified, 228 underwent full text review, and we identified 42 different instruments of delirium severity. Eleven of the 42 tools were multidomain, delirium-specific instruments providing a quantitative rating of delirium severity; these instruments underwent a methodologic quality review. Applying prespecified criteria related to frequency of use, methodologic quality, construct or predictive validity, and broad domain coverage, an expert panel used an iterative modified Delphi process to select 6 final high-quality instruments meeting these criteria: the Confusion Assessment Method-Severity Score, Confusional State Examination, Delirium-O-Meter, Delirium Observation Scale, Delirium Rating Scale, and Memorial Delirium Assessment Scale.

Conclusions and Relevance

The 6 instruments identified may enable accurate measurement of delirium severity to improve clinical care for patients with this condition. This work may stimulate increased usage and head-to-head comparison of these instruments.

Reliability and accuracy of delirium assessments among investigators at multiple international centres

INTRODUCTION

Delirium is a common, serious postoperative complication. For clinical studies to generate valid findings, delirium assessments must be standardised and administered accurately by independent researchers. The Confusion Assessment Method (CAM) is a widely used delirium assessment tool. The objective was to determine whether implementing a standardised CAM training protocol for researchers at multiple international sites yields reliable inter-rater assessment and accurate delirium diagnosis.

METHODS

Patients consented to video recordings of CAM delirium assessments for research purposes. Raters underwent structured training in CAM administration. Training entailed didactic education, role-playing with intensive feedback, apprenticeship with experienced researchers and group discussions of complex cases. Raters independently viewed and scored nine video-recorded CAM interviews. Inter-rater reliability was determined using Fleiss kappa. Accuracy was judged by comparing raters' scores with those of an expert delirium researcher.

RESULTS

Twenty-seven raters from eight international research centres completed the study and achieved almost perfect agreement for overall delirium diagnosis, kappa=0.88 (95% CI 0.85 to 0.92). Agreement of the four core CAM features ranged from fair to substantial. The sensitivity and specificity for identifying delirium were 72% (95% CI 60% to 81%) and 99% (95% CI 96% to 100%), considering an expert rater's scores as the reference standard (delirious, n=3; non-delirious, n=6). Delirium severity ratings were tightly clustered, with most scores within 5% of the median.

CONCLUSION

Our results demonstrate that, with appropriate training and ongoing scoring discussions, researchers at multiple sites can reliably detect delirium in postsurgical patients. These results support the premise that methodologically rigorous multi-centre studies can yield standardised and accurate determinations of delirium.

The Better Assessment of Illness Study for Delirium Severity: Study Design, Procedures, and Cohort Description

BACKGROUND/OBJECTIVES

To describe the design, procedures, and cohort for the Better ASsessment of ILlness -(BASIL) study, which is conducted to develop and test new delirium severity measures, compare them with existing measures, and examine related clinical outcomes.

METHODS

Prospective cohort study with 1 year follow-up of study participants at a large teaching hospital in Boston, Massachusetts. After brief cognitive testing and the Delirium Symptom Interview, delirium and delirium severity were rated daily in the hospital using the Confusion Assessment Method (CAM) and CAM-Severity score, the Delirium Rating Scale-Revised-98 (DRS-R-98), and the Memorial Delirium Assessment Scale (MDAS). Other key study variables included comorbidity, physical function (basic and instrumental activities of daily living [ADL]), ratings of subjective health and well-being, and clinical outcomes (length of stay, 30 day rehospitalization, nursing home admission, healthcare utilization). Follow-up interviews occurred at 1- and 12-month with patients and families. In 42 patient interviews, inter-rater reliability for key variables was assessed.

RESULTS

Of 768 eligible patients approached, 469 were screened and 352 enrolled, yielding an overall study response rate of 67% for potentially eligible participants. The mean participant was 80.3 years old (SD 6.8) and 203 (58%) were female. The majority of patients were medically complex with Charlson Comorbidity Scores ≥2 (192 patients, 55%), and 102 (29%) met criteria for dementia. Inter-rater reliability assessments (n = 42 pairs) were high for overall ratings of presence or absence of delirium by CAM (κ = 1.0), delirium severity by DRS-R-98 and MDAS (weighted kappa, κ = 1.0 for each) and for ADL impairment (κ = 1.0). For eligible participants at each time point, 278 out of 308 (90%) completed the 1-month follow-up and 132 out of 256 (53%) have completed the 12-month follow-up to date, which is still in progress. Among those who completed interviews, there was only 1-3% missing data on most major outcomes (delirium, basic ADL, and readmission).

CONCLUSION

The BASIL study presents an innovative effort to advance the conceptualization and measurement of delirium severity. Unique strengths include the diverse cohort with complete high quality data and longitudinal follow-up, along with detailed collection of multiple delirium measures daily during hospitalization.

Clinical outcomes in older surgical patients with mild cognitive impairment

INTRODUCTION

Older adults, including those with mild cognitive impairment (MCI), are increasingly undergoing surgery.

METHODS

Relative risks (RRs) of MCI alone or with delirium on adverse outcomes were estimated in an ongoing prospective, observational cohort study of 560 nondemented adults aged ≥70 years.

RESULTS

MCI (n = 61, 11%) was associated with increased RR of delirium (RR = 1.9, P < .001) and delirium severity (RR = 4.6, P < .001). Delirium alone (n = 107), but not MCI alone (n = 34), was associated with multiple adverse outcomes including more major postoperative complication(s) (RR = 2.5, P = .002) and longer length of stay (RR = 2.2, P < .001). Patients with concurrent MCI and delirium (n = 27) were more often discharged to a postacute facility (RR = 1.4, P < .001) and had synergistically increased risk for new impairments in cognitive functioning (RR = 3.6, P < .001).

DISCUSSION

MCI is associated with increased risk of delirium incidence and severity. Patients with delirium and MCI have synergistically elevated risk of developing new difficulties in cognitively demanding tasks.

Delirium Severity Post-Surgery and its Relationship with Long-Term Cognitive Decline in a Cohort of Patients without Dementia

BACKGROUND

Delirium has been associated with more rapid cognitive decline. However, it is unknown whether increased delirium severity is associated with a higher rate of long-term cognitive decline.

OBJECTIVE

To evaluate delirium severity and the presence and rate of cognitive decline over 36 months following surgery.

METHODS

We examined patients from the Successful Aging after Elective Surgery Study, who were age ≥70 years undergoing major elective surgery (N = 560). Delirium severity was determined by the peak Confusion Assessment Method-Severity (CAM-S) score for each patient's hospitalization and grouped based on the sample distribution: scores of 0-2, 3-7, and 8-19. A neuropsychological composite, General Cognitive Performance (GCP), and proxy-reported Informant Questionnaire for Cognitive Decline (IQCODE) were used to examine cognitive outcomes following surgery at 0, 1, and 2 months, and then every 6 months for up to 3 years.

RESULTS

No significant cognitive decline was observed for patients with peak CAM-S scores 0-2 (-0.17 GCP units/year, 95% confidence interval [CI] -0.35, 0.01). GCP scores decreased significantly in the group with peak CAM-S scores 3-7 (-0.30 GCP units/year, 95% CI -0.51, -0.09), and decreased almost three times faster in the highest delirium severity group (peak CAM-S scores 8-19; -0.82 GCP units/year, 95% CI -1.28, -0.37). A similar association was found for delirium severity and the proportion of patients who developed IQCODE impairment over time.

CONCLUSION

Patients with the highest delirium severity experienced the greatest rate of cognitive decline, which exceeds the rate previously observed for patients with dementia, on serial neuropsychological testing administered over 3 years, with a dose-response relationship between delirium severity and long-term cognitive decline.