Diagnostic test accuracy of informant-based tools to diagnose dementia in older hospital patients with delirium: a prospective cohort study

Differences in metalloproteinases and their tissue inhibitors in the cerebrospinal fluid are associated with delirium

BACKGROUND

The aetiology of delirium is not known, but pre-existing cognitive impairment is a predisposing factor. Here we explore the associations between delirium and cerebrospinal fluid (CSF) levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), proteins with important roles in both acute injury and chronic neurodegeneration.

METHODS

Using a 13-plex Discovery Assay®, we quantified CSF levels of 9 MMPs and 4 TIMPs in 280 hip fracture patients (140 with delirium), 107 cognitively unimpaired individuals, and 111 patients with Alzheimer's disease dementia. The two delirium-free control groups without acute trauma were included to unravel the effects of acute trauma (hip fracture), dementia, and delirium.

RESULTS

Here we show that delirium is associated with higher levels of MMP-2, MMP-3, MMP-10, TIMP-1, and TIMP-2; a trend suggests lower levels of TIMP-4 are also associated with delirium. Most delirium patients had pre-existing dementia and low TIMP-4 is the only marker associated with delirium in adjusted analyses. MMP-2, MMP-12, and TIMP-1 levels are clearly higher in the hip fracture patients than in both control groups and several other MMP/TIMPs are impacted by acute trauma or dementia status.

CONCLUSIONS

Several CSF MMP/TIMPs are significantly associated with delirium in hip fracture patients, but alterations in most of these MMP/TIMPs could likely be explained by acute trauma and/or pre-fracture dementia. Low levels of TIMP-4 appear to be directly associated with delirium, and the role of this marker in delirium pathophysiology should be further explored.

Impaired glucose utilization in the brain of patients with delirium following hip fracture

Alterations in brain energy metabolism have long been proposed as one of several neurobiological processes contributing to delirium. This is supported by previous findings of altered CSF lactate and neuron-specific enolase concentrations and decreased glucose uptake on brain-PET in patients with delirium. Despite this, there are limited data on metabolic alterations found in CSF samples, and targeted metabolic profiling of CSF metabolites involved in energy metabolism has not been performed. The aim of the study was to investigate whether metabolites related to energy metabolism in the serum and CSF of patients with hip fracture are associated with delirium. The study cohort included 406 patients with a mean age of 81 years (standard deviation 10 years), acutely admitted to hospital for surgical repair of a hip fracture. Delirium was assessed daily until the fifth postoperative day. CSF was collected from all 406 participants at the onset of spinal anaesthesia, and serum samples were drawn concurrently from 213 participants. Glucose and lactate in CSF were measured using amperometry, whereas plasma glucose was measured in the clinical laboratory using enzymatic photometry. Serum and CSF concentrations of the branched-chain amino acids, 3-hydroxyisobutyric acid, acetoacetate and β-hydroxybutyrate were measured using gas chromatography-tandem mass spectrometry (GC-MS/MS). In total, 224 (55%) patients developed delirium pre- or postoperatively. Ketone body concentrations (acetoacetate, β-hydroxybutyrate) and branched-chain amino acids were significantly elevated in the CSF but not in serum among patients with delirium, despite no group differences in glucose concentrations. The level of 3-hydroxyisobutyric acid was significantly elevated in both CSF and serum. An elevation of CSF lactate during delirium was explained by age and comorbidity. Our data suggest that altered glucose utilization and a shift to ketone body metabolism occurs in the brain during delirium.

Diagnostic accuracy of Ascertain Dementia 8-item Questionnaire by participant and informant-A systematic review and meta-analysis

BACKGROUND

The Ascertain Dementia 8-item Questionnaire (AD8) is a screening tool for cognitive impairment that can be administered to older persons and/or their informants.

OBJECTIVES

To evaluate the diagnostic accuracy and compare the predictive parameters of the informant and participant-completed Ascertain Dementia 8-item Questionnaire (iAD8 and pAD8, respectively) in older adults with cognitive impairment.

METHODS/DESIGN

We searched ten electronic databases (including MEDLINE (Ovid), Embase) from tool inception to March 2022. We included studies with patients ≥60 years old that were screened for cognitive impairment using AD8 in any healthcare setting. Predictive parameters were assessed against reference standards to estimate accuracy and diagnostic ability using bivariate random-effects meta-analyses. We used QUADAS-2 criteria to assess risk of bias.

RESULTS

A cut-off of ≥2/8 was used to classify mild cognitive impairment (MCI), dementia, and cognitive impairment (MCI or dementia). Seven studies using the iAD8 (n = 794) showed a sensitivity of 80% and specificity of 79% to detect MCI. Nine studies using the iAD8 (n = 2393) established 91% sensitivity and 64% specificity to detect dementia. To detect MCI using the pAD8, four studies (n = 836) showed 57% sensitivity and 71% specificity. To detect dementia using the pAD8, four studies (n = 3015) demonstrated 82% sensitivity and 75% specificity. Recurring high or unclear risk of bias was noted in the domains of "Index test" and "reference standard".

CONCLUSIONS

The diagnostic accuracy of iAD8 is superior to that of pAD8 when screening for cognitive impairment. The AD8 may be an acceptable alternative to screen for cognitive impairment in older adults when there are limitations to formal testing.

Dual-stage cognitive assessment: a two-stage screening for cognitive impairment in primary care

BACKGROUND

Aging population has led to an increased proportion of older adults and cognitively impaired. We designed a brief and flexible two-stage cognitive screening scale, the Dual-Stage Cognitive Assessment (DuCA), for cognitive screening in primary care settings.

METHOD

In total, 1,772 community-dwelling participants were recruited, including those with normal cognition (NC, n = 1,008), mild cognitive impairment (MCI, n = 633), and Alzheimer's disease (AD, n = 131), and administered a neuropsychological test battery and the DuCA. To improve performance, the DuCA combines visual and auditory memory tests for an enhanced memory function test.

RESULTS

The correlation coefficient between DuCA-part 1 and DuCA-total was 0.84 (P < 0.001). The correlation coefficients of DuCA-part 1 with Addenbrooke's Cognitive Examination III (ACE-III) and Montreal Cognitive Assessment Basic (MoCA-B) were 0.66 (P < 0.001) and 0.85 (P < 0.001), respectively. The correlation coefficients of DuCA-total with ACE-III and MoCA-B were 0.78 (P < 0.001) and 0.83 (P < 0.001), respectively. DuCA-Part 1 showed a similar discrimination ability for MCI from NC (area under curve [AUC] = 0.87, 95%CI 0.848-0.883) as ACE III (AUC = 0.86, 95%CI 0.838-0.874) and MoCA-B (AUC = 0.85, 95%CI 0.830-0.868). DuCA-total had a higher AUC (0.93, 95%CI: 0.917-0.942). At different education levels, the AUC was 0.83-0.84 for DuCA-part 1, and 0.89-0.94 for DuCA-total. DuCA-part 1 and DuCA-total's ability to discriminate AD from MCI was 0.84 and 0.93, respectively.

CONCLUSION

DuCA-Part 1 would aid rapid screening and supplemented with the second part for a complete assessment. DuCA is suited for large-scale cognitive screening in primary care, saving time and eliminating the need for extensively training assessors.

Development of a UK core dataset for geriatric medicine research: a position statement and results from a Delphi consensus process

BACKGROUND

There is lack of standardisation in assessment tools used in geriatric medicine research, which makes pooling of data and cross-study comparisons difficult.

METHODS

We conducted a modified Delphi process to establish measures to be included within core and extended datasets for geriatric medicine research in the United Kingdom (UK). This included three complete questionnaire rounds, and one consensus meeting. Participants were selected from attendance at the NIHR Newcastle Biomedical Research Centre meeting, May 2019, and academic geriatric medicine e-mailing lists. Literature review was used to develop the initial questionnaire, with all responses then included in the second questionnaire. The third questionnaire used refined options from the second questionnaire with response ranking.

RESULTS

Ninety-eight responses were obtained across all questionnaire rounds (Initial: 19, Second: 21, Third: 58) from experienced and early career researchers in geriatric medicine. The initial questionnaire included 18 questions with short text responses, including one question for responders to suggest additional items. Twenty-six questions were included in the second questionnaire, with 108 within category options. The third questionnaire included three ranking, seven final agreement, and four binary option questions. Results were discussed at the consensus meeting. In our position statement, the final consensus dataset includes six core domains: demographics (age, gender, ethnicity, socioeconomic status), specified morbidities, functional ability (Barthel and/or Nottingham Extended Activities of Daily Living), Clinical Frailty Scale (CFS), cognition, and patient-reported outcome measures (dependent on research question). We also propose how additional variables should be measured within an extended dataset.

CONCLUSIONS

Our core and extended datasets represent current consensus opinion of academic geriatric medicine clinicians across the UK. We consider the development and further use of these datasets will strengthen collaboration between researchers and academic institutions.

Cerebrospinal fluid quinolinic acid is strongly associated with delirium and mortality in hip-fracture patients

BACKGROUNDThe kynurenine pathway (KP) has been identified as a potential mediator linking acute illness to cognitive dysfunction by generating neuroactive metabolites in response to inflammation. Delirium (acute confusion) is a common complication of acute illness and is associated with increased risk of dementia and mortality. However, the molecular mechanisms underlying delirium, particularly in relation to the KP, remain elusive.METHODSWe undertook a multicenter observational study with 586 hospitalized patients (248 with delirium) and investigated associations between delirium and KP metabolites measured in cerebrospinal fluid (CSF) and serum by targeted metabolomics. We also explored associations between KP metabolites and markers of neuronal damage and 1-year mortality.RESULTSIn delirium, we found concentrations of the neurotoxic metabolite quinolinic acid in CSF (CSF-QA) (OR 2.26 [1.78, 2.87], P < 0.001) to be increased and also found increases in several other KP metabolites in serum and CSF. In addition, CSF-QA was associated with the neuronal damage marker neurofilament light chain (NfL) (β 0.43, P < 0.001) and was a strong predictor of 1-year mortality (HR 4.35 [2.93, 6.45] for CSF-QA ≥ 100 nmol/L, P < 0.001). The associations between CSF-QA and delirium, neuronal damage, and mortality remained highly significant following adjustment for confounders and multiple comparisons.CONCLUSIONOur data identified how systemic inflammation, neurotoxicity, and delirium are strongly linked via the KP and should inform future delirium prevention and treatment clinical trials that target enzymes of the KP.FUNDINGNorwegian Health Association and South-Eastern Norway Regional Health Authorities.

Informant-based screening tools for dementia: an overview of systematic reviews

BACKGROUND

Informant-based questionnaires may have utility for cognitive impairment or dementia screening. Reviews describing the accuracy of respective questionnaires are available, but their focus on individual questionnaires precludes comparisons across tools. We conducted an overview of systematic reviews to assess the comparative accuracy of informant questionnaires and identify areas where evidence is lacking.

METHODS

We searched six databases to identify systematic reviews describing diagnostic test accuracy of informant questionnaires for cognitive impairment or dementia. We pooled sensitivity and specificity data for each questionnaire and used network approaches to compare accuracy estimates across the differing tests. We used grading of recommendations, assessment, development and evaluation (GRADE) to evaluate the overall certainty of evidence. Finally, we created an evidence 'heat-map', describing the availability of accurate data for individual tests in different populations and settings.

RESULTS

We identified 25 reviews, consisting of 93 studies and 13 informant questionnaires. Pooled analysis (37 studies; 11 052 participants) ranked the eight-item interview to ascertain dementia (AD8) highest for sensitivity [90%; 95% credible intervals (CrI) = 82-95; 'best-test' probability = 36]; while the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) was most specific (81%; 95% CrI = 66-90; 'best-test' probability = 29%). GRADE-based evaluation of evidence suggested certainty was 'low' overall. Our heat-map indicated that only AD8 and IQCODE have been extensively evaluated and most studies have been in the secondary care settings.

CONCLUSIONS

AD8 and IQCODE appear to be valid questionnaires for cognitive impairment or dementia assessment. Other available informant-based cognitive screening questionnaires lack evidence to justify their use at present. Evidence on the accuracy of available tools in primary care settings and with specific populations is required.

The evidence for introducing case-finding for delirium and dementia in older medical inpatients in a New Zealand hospital

OBJECTIVE

The aim of this project was to make the case to the managers of a large urban teaching hospital in New Zealand for the introduction of systematic case-finding for pre-existing cognitive impairment/dementia in older hospital inpatients that screen positive for delirium.

METHOD

Two hundred consecutive acute admissions aged 75+ in four medical wards were assessed using the 4AT assessment tool for delirium and the Alzheimer Questionnaire (AQ) for pre-existing cognitive impairment/dementia. Length of stay and mortality at 1 year were also collected.

RESULTS

Over a third of the sample screened positive for delirium and nearly two-thirds of these also screened positive for dementia. The median length of stay was 5 days for delirium without dementia and 7 days for delirium with dementia, compared to 3 days for those who screened negative for both. After adjustment for age, gender and ethnic group, people who screened positive for delirium (with or without dementia) had 50% longer length of stay (p < 0.05) and at least double the risk of death (p < 0.05).

CONCLUSION

Older hospital inpatients that screen positive for delirium and dementia using 4AT and AQ have longer lengths of stay and higher mortality. Identification may lead to more timely interventions that help to improve health outcomes and reduce hospital costs.

Brain FDG PET for Short- to Medium-Term Prediction of Further Cognitive Decline and Need for Assisted Living in Acutely Hospitalized Geriatric Patients With Newly Detected Clinically Uncertain Cognitive Impairment

PURPOSE

The aim of this study was to evaluate brain FDG PET for short- to medium-term prediction of cognitive decline, need for assisted living, and survival in acutely hospitalized geriatric patients with newly detected clinically uncertain cognitive impairment (CUCI).

MATERIALS AND METHODS

The study included 96 patients (62 females, 81.4 ± 5.4 years) hospitalized due to (sub)acute admission indications with newly detected CUCI (German Clinical Trials Register DRKS00005041). FDG PET was categorized as "neurodegenerative" (DEG+) or "nonneurodegenerative" (DEG-) based on visual inspection by 2 independent readers. In addition, each individual PET was tested voxel-wise against healthy controls (P < 0.001 uncorrected). The resulting total hypometabolic volume (THV) served as reader-independent measure of the spatial extent of neuronal dysfunction/degeneration. FDG PET findings at baseline were tested for association with the change in living situation and change in vital status 12 to 24 months after PET. The association with the annual change of the CDR-SB (Clinical Dementia Rating Sum of Boxes) after PET was tested in a subsample of 72 patients.

RESULTS

The mean time between PET and follow-up did not differ between DEG+ and DEG- patients (1.37 ± 0.27 vs 1.41 ± 0.27 years, P = 0.539). Annual change of CDR-SB was higher in DEG+ compared with DEG- patients (2.78 ± 2.44 vs 0.99 ± 1.81, P = 0.001), and it was positively correlated with THV (age-corrected Spearman ρ = 0.392, P = 0.001). DEG+ patients moved from at home to assisted living significantly earlier than DEG- patients (P = 0.050). Survival was not associated with DEG status or with THV.

CONCLUSIONS

In acutely hospitalized geriatric patients with newly detected CUCI, the brain FDG PET can contribute to the prediction of further cognitive/functional decline and the need for assisted living within 1 to 2 years.

Comparison of delirium detection tools in acute care : A rapid review

Background

Delirium is a frequent psychopathological syndrome in geriatric patients. It is sometimes the only symptom of acute illness and bears a high risk for complications. Therefore, feasible assessments are needed for delirium detection.

Objective and methods

Rapid review of available delirium assessments based on a current Medline search and cross-reference check with a special focus on those implemented in acute care hospital settings.

Results

A total of 75 delirium detection tools were identified. Many focused on inattention as well as acute onset and/or fluctuating course of cognitive changes as key features for delirium. A range of assessments are based on the confusion assessment method (CAM) that has been adapted for various clinical settings. The need for a collateral history, time resources and staff training are major challenges in delirium assessment. Latest tests address these through a two-step approach, such as the ultrabrief (UB) CAM or by optional assessment of temporal aspects of cognitive changes (4 As test, 4AT). Most delirium screening assessments are validated for patient interviews, some are suitable for monitoring delirium symptoms over time or diagnosing delirium based on collateral history only.

Conclusion

Besides the CAM the 4AT has become well-established in acute care because of its good psychometric properties and practicability. There are several other instruments extending and improving the possibilities of delirium detection in different clinical settings.

Supplementary Information

The online version of this article (10.1007/s00391-021-02003-5) contains supplementary material, which is available to authorized users.

Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for the early detection of dementia across a variety of healthcare settings

BACKGROUND

The Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) is a structured interview based on informant responses that is used to assess for possible dementia. IQCODE has been used for retrospective or contemporaneous assessment of cognitive decline. There is considerable interest in tests that may identify those at future risk of developing dementia. Assessing a population free of dementia for the prospective development of dementia is an approach often used in studies of dementia biomarkers. In theory, questionnaire-based assessments, such as IQCODE, could be used in a similar way, assessing for dementia that is diagnosed on a later (delayed) assessment.

OBJECTIVES

To determine the accuracy of the informant-based questionnaire IQCODE for the early detection of dementia across a variety of health care settings.

SEARCH METHODS

We searched these sources on 16 January 2016: ALOIS (Cochrane Dementia and Cognitive Improvement Group), MEDLINE Ovid SP, Embase Ovid SP, PsycINFO Ovid SP, BIOSIS Previews on Thomson Reuters Web of Science, Web of Science Core Collection (includes Conference Proceedings Citation Index) on Thomson Reuters Web of Science, CINAHL EBSCOhost, and LILACS BIREME. We also searched sources specific to diagnostic test accuracy: MEDION (Universities of Maastricht and Leuven); DARE (Database of Abstracts of Reviews of Effects, in the Cochrane Library); HTA Database (Health Technology Assessment Database, in the Cochrane Library), and ARIF (Birmingham University). We checked reference lists of included studies and reviews, used searches of included studies in PubMed to track related articles, and contacted research groups conducting work on IQCODE for dementia diagnosis to try to find additional studies. We developed a sensitive search strategy; search terms were designed to cover key concepts using several different approaches run in parallel, and included terms relating to cognitive tests, cognitive screening, and dementia. We used standardised database subject headings, such as MeSH terms (in MEDLINE) and other standardised headings (controlled vocabulary) in other databases, as appropriate.

SELECTION CRITERIA

We selected studies that included a population free from dementia at baseline, who were assessed with the IQCODE and subsequently assessed for the development of dementia over time. The implication was that at the time of testing, the individual had a cognitive problem sufficient to result in an abnormal IQCODE score (defined by the study authors), but not yet meeting dementia diagnostic criteria.

DATA COLLECTION AND ANALYSIS

We screened all titles generated by the electronic database searches, and reviewed abstracts of all potentially relevant studies. Two assessors independently checked the full papers for eligibility and extracted data. We determined quality assessment (risk of bias and applicability) using the QUADAS-2 tool, and reported quality using the STARDdem tool.

MAIN RESULTS

From 85 papers describing IQCODE, we included three papers, representing data from 626 individuals. Of this total, 22% (N = 135/626) were excluded because of prevalent dementia. There was substantial attrition; 47% (N = 295) of the study population received reference standard assessment at first follow-up (three to six months) and 28% (N = 174) received reference standard assessment at final follow-up (one to three years). Prevalence of dementia ranged from 12% to 26% at first follow-up and 16% to 35% at final follow-up. The three studies were considered to be too heterogenous to combine, so we did not perform meta-analyses to describe summary estimates of interest. Included patients were poststroke (two papers) and hip fracture (one paper). The IQCODE was used at three thresholds of positivity (higher than 3.0, higher than 3.12 and higher than 3.3) to predict those at risk of a future diagnosis of dementia. Using a cut-off of 3.0, IQCODE had a sensitivity of 0.75 (95%CI 0.51 to 0.91) and a specificity of 0.46 (95%CI 0.34 to 0.59) at one year following stroke. Using a cut-off of 3.12, the IQCODE had a sensitivity of 0.80 (95%CI 0.44 to 0.97) and specificity of 0.53 (95C%CI 0.41 to 0.65) for the clinical diagnosis of dementia at six months after hip fracture. Using a cut-off of 3.3, the IQCODE had a sensitivity of 0.84 (95%CI 0.68 to 0.94) and a specificity of 0.87 (95%CI 0.76 to 0.94) for the clinical diagnosis of dementia at one year after stroke. In generaI, the IQCODE was sensitive for identification of those who would develop dementia, but lacked specificity. Methods for both excluding prevalent dementia at baseline and assessing for the development of dementia were varied, and had the potential to introduce bias.

AUTHORS' CONCLUSIONS

Included studies were heterogenous, recruited from specialist settings, and had potential biases. The studies identified did not allow us to make specific recommendations on the use of the IQCODE for the future detection of dementia in clinical practice. The included studies highlighted the challenges of delayed verification dementia research, with issues around prevalent dementia assessment, loss to follow-up over time, and test non-completion potentially limiting the studies. Future research should recognise these issues and have explicit protocols for dealing with them.

Current Challenges in the Recognition and Management of Delirium Superimposed on Dementia

Delirium occurring in a patient with preexisting dementia is referred to as delirium superimposed on dementia (DSD). DSD commonly occurs in older hospitalized patients and is associated with worse outcomes, including higher rates of mortality and institutionalization, compared to inpatients with delirium or dementia alone. This narrative review summarizes the screening, diagnosis, management, and pathophysiology of DSD and concludes by highlighting opportunities for future research. Studies were identified via Medline and PsycINFO keyword search, and handsearching reference lists. Conceptually, DSD could be considered an "acute exacerbation" of dementia precipitated by a noxious insult akin to an acute exacerbation of heart failure or acute on chronic renal failure. However, unlike other organ systems, there are no established biomarkers for delirium, so DSD is diagnosed and monitored clinically. Because cognitive dysfunction is common to both delirium and dementia, the diagnosis of DSD can be challenging. Inattention, altered levels of arousal, and motor dysfunction may help distinguish DSD from dementia alone. An informant history suggestive of an acute change in cognition or alertness should be investigated and managed as delirium until proven otherwise. The key management principles include prevention, identifying and treating the underlying precipitant(s), implementing multicomponent interventions to create an ideal environment for brain recovery, preventing complications, managing distress, and monitoring for resolution. Informing and involving family members or caregivers throughout the patient journey are essential because there is significant prognostic uncertainty, including the risk of persistent cognitive and functional decline following DSD and relapse. Furthermore, informal carers can provide significant assistance in management. Emerging evidence demonstrates that increased exposure to delirium is associated with neuronal injury and worse cognitive outcomes although the mechanisms through which this occurs remain unclear. Given the clinical overlap between delirium and dementia, studying shared pathophysiological pathways may uncover diagnostic tests and is an essential step in therapeutic innovation.

Factors associated with utilization of emotion and personality instruments among neuropsychologists

Historically, assessment of emotion and personality functioning was not emphasized by clinical neuropsychologists, who instead focused almost exclusively on the evaluation of cognitive functioning. This study examined current practices regarding clinical neuropsychologists' usage of instruments for assessing emotion and personality, along with factors that may mediate their choice of measures and their beliefs about evaluating emotion and personality. Participants were 117 board-certified neuropsychologists as recognized by the American Board of Professional Psychology (ABPP-CN), many of whom had been practicing for over 20 years (39%). Participants generally indicated that examining emotion and personality is essential to evaluations. There was variability among participants as to whether assessment of emotion and personality functioning is challenging, as well as whether or not clinical interview was better suited than instruments. Patients' lack of self-awareness, purposeful over- and under-exaggeration, and lack of sensitivity and specificity of the assessment instruments for neurologic disorders/conditions were identified as the greatest challenges in this area of assessment. Results of the survey suggest that further advancement in the construction and availability of emotion/personality instruments is necessary.

Informant-based screening tools for diagnosis of dementia, an overview of systematic reviews of test accuracy studies protocol

BACKGROUND

Robust diagnosis of dementia requires an understanding of the accuracy of the available diagnostic tests. Informant questionnaires are frequently used to assess for dementia in clinical practice. Recent systematic reviews have sought to establish the diagnostic test accuracy of various dementia informant screening tools. However, most reviews to date have focused on a single diagnostic tool and this does not address which tool is 'best'. A key aim of the overview of systematic reviews is to present a disparate evidence base in a single, easy to access platform.

METHODS

We will conduct an overview of systematic reviews in which we 'review the systematic reviews' of diagnostic test accuracy studies evaluating informant questionnaires for dementia. As an overview of systematic reviews of test accuracy is a relatively novel approach, we will use this review to explore methods for visual representation of complex data, for highlighting evidence gaps and for indirect comparative analyses. We will create a list of informant tools by consulting with dementia experts. We will search 6 databases (EMBASE (OVID); Health and Psychosocial Instruments (OVID); Medline (OVID); CINAHL (EBSCO); PSYCHinfo (EBSCO) and the PROSPERO registry of review protocols) to identify systematic reviews that describe the diagnostic test accuracy of informant questionnaires for dementia. We will assess review quality using the AMSTAR-2 (Assessment of Multiple Systematic Reviews) and assess reporting quality using PRISMA-DTA (Preferred Reporting Items for Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies) checklists. We will collate the identified reviews to create an 'evidence map' that highlights where evidence does and does not exist in relation to informant questionnaires. We will pool sensitivity and specificity data via meta-analysis to generate a diagnostic test accuracy summary statistic for each informant questionnaire. If data allow, we will perform a statistical comparison of the diagnostic test accuracy of each informant questionnaire using a network approach.

DISCUSSION

Our overview of systematic reviews will provide a concise summary of the diagnostic test accuracy of informant tools and highlight areas where evidence is currently lacking in this regard. It will also apply network meta-analysis techniques to a new area.

The 4 'A's test for detecting delirium in acute medical patients: a diagnostic accuracy study

BACKGROUND

Delirium is a common and serious neuropsychiatric syndrome, usually triggered by illness or drugs. It remains underdetected. One reason for this is a lack of brief, pragmatic assessment tools. The 4 'A's test (Arousal, Attention, Abbreviated Mental Test - 4, Acute change) (4AT) is a screening tool designed for routine use. This project evaluated its usability, diagnostic accuracy and cost.

METHODS

Phase 1 - the usability of the 4AT in routine practice was measured with two surveys and two qualitative studies of health-care professionals, and a review of current clinical use of the 4AT as well as its presence in guidelines and reports. Phase 2 - the 4AT's diagnostic accuracy was assessed in newly admitted acute medical patients aged ≥ 70 years. Its performance was compared with that of the Confusion Assessment Method (CAM; a longer screening tool). The performance of individual 4AT test items was related to cognitive status, length of stay, new institutionalisation, mortality at 12 weeks and outcomes. The method used was a prospective, double-blind diagnostic test accuracy study in emergency departments or in acute general medical wards in three UK sites. Each patient underwent a reference standard delirium assessment and was also randomised to receive an assessment with either the 4AT (n = 421) or the CAM (n = 420). A health economics analysis was also conducted.

RESULTS

Phase 1 found evidence that delirium awareness is increasing, but also that there is a need for education on delirium in general and on the 4AT in particular. Most users reported that the 4AT was useful, and it was in widespread use both in the UK and beyond. No changes to the 4AT were considered necessary. Phase 2 involved 785 individuals who had data for analysis; their mean age was 81.4 (standard deviation 6.4) years, 45% were male, 99% were white and 9% had a known dementia diagnosis. The 4AT (n = 392) had an area under the receiver operating characteristic curve of 0.90. A positive 4AT score (> 3) had a specificity of 95% [95% confidence interval (CI) 92% to 97%] and a sensitivity of 76% (95% CI 61% to 87%) for reference standard delirium. The CAM (n = 382) had a specificity of 100% (95% CI 98% to 100%) and a sensitivity of 40% (95% CI 26% to 57%) in the subset of participants whom it was possible to assess using this. Patients with positive 4AT scores had longer lengths of stay (median 5 days, interquartile range 2.0-14.0 days) than did those with negative 4AT scores (median 2 days, interquartile range 1.0-6.0 days), and they had a higher 12-week mortality rate (16.1% and 9.2%, respectively). The estimated 12-week costs of an initial inpatient stay for patients with delirium were more than double the costs of an inpatient stay for patients without delirium (e.g. in Scotland, £7559, 95% CI £7362 to £7755, vs. £4215, 95% CI £4175 to £4254). The estimated cost of false-positive cases was £4653, of false-negative cases was £8956, and of a missed diagnosis was £2067.

LIMITATIONS

Patients were aged ≥ 70 years and were assessed soon after they were admitted, limiting generalisability. The treatment of patients in accordance with reference standard diagnosis limited the ability to assess comparative cost-effectiveness.

CONCLUSIONS

These findings support the use of the 4AT as a rapid delirium assessment instrument. The 4AT has acceptable diagnostic accuracy for acute older patients aged > 70 years.

FUTURE WORK

Further research should address the real-world implementation of delirium assessment. The 4AT should be tested in other populations.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN53388093.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 40. See the NIHR Journals Library website for further project information. The funder specified that any new delirium assessment tool should be compared against the CAM, but had no other role in the study design or conduct of the study.

The short IQCODE as a predictor for delirium in hospitalized geriatric patients

BACKGROUND

Delirium is a serious complication, which occurs frequently in older patients with pre-existing cognitive impairment. There is a need for a simple tool to assess chronic cognitive impairment and the associated risk of delirium during hospitalization.

AIMS

To assess the usefulness of the short IQCODE questionnaire in predicting delirium during hospitalization in older patients in a geriatric ward.

METHODS

A prognostic study in the Geriatric Department at Aarhus University Hospital, Aarhus Denmark. Consecutive patients were enrolled during March to December, 2017. After consent of the patient, the staff interviewed the relatives by phone using the short IQCODE questionnaire. Delirium was assessed morning and evening until discharge by the Confusion Assessment Method. The ability of short IQCODE to predict delirium was examined.

RESULTS

Three hundred and fifty-three patients were eligible, and 306 completed the IQCODE. Delirium occurred among 19% of the patients during hospitalization. The IQCODE score was associated with the risk of delirium with a receiver operating characteristic (ROC) area of 0.72. A cut-point of 3.3 could separate the patients in a larger group with a risk of approximately 26% to develop delirium and a smaller group having a risk of approximately 6%.

CONCLUSION

The IQCODE is a useful tool to predict delirium among older inpatients, but it may not stand alone. It can be a useful supplement to other clinical information and observations in detecting patients needing dementia-friendly treatment and care.

Prospective Investigation of Markers of Elevated Delirium Risk (PRIMED Risk) study protocol: a prospective, observational cohort study investigating blood and cerebrospinal fluid biomarkers for delirium and cognitive dysfunction in older patients

Background: Delirium is a common post-operative complication, particularly in older adults undergoing major or emergency procedures. It is associated with increased length of intensive care and hospital stay, post-operative mortality and subsequent dementia risk. Current methods of predicting delirium incidence, duration and severity have limitations. Investigation of blood and cerebrospinal fluid (CSF) biomarkers linked to delirium may improve understanding of the underlying pathophysiology, particularly with regard to the extent this is shared or distinct with underlying dementia. Together, these have the potential for development of better risk stratification tools and perioperative interventions. Methods: 200 patients over the age of 70 scheduled for surgery with routine spinal anaesthetic will be recruited from UK hospitals. Their cognitive and functional baseline status will be assessed pre-operatively by telephone. Time-matched CSF and blood samples will be taken at the time of surgery and analysed for known biomarkers of neurodegeneration and neuroinflammation. Patients will be assessed daily for delirium until hospital discharge and will have regular cognitive follow-up for two years. Primary outcomes will be change in modified Telephone Interview for Cognitive Status (TICS-m) score at 12 months and rate of change of TICS-m score. Delirium severity, duration and biomarker levels will be treated as exposures in a random effects linear regression models. PRIMED Risk has received regulatory approvals from Health Research Authority and London – South East Research Ethics Committee. Discussion: The main anticipated output from this study will be the quantification of biomarkers of acute and chronic contributors to cognitive impairment after surgery. In addition, we aim to develop better risk prediction models for adverse cognitive outcomes.

Delirium is prevalent in older hospital inpatients and associated with adverse outcomes: results of a prospective multi-centre study on World Delirium Awareness Day

BACKGROUND

Delirium is a common severe neuropsychiatric condition secondary to physical illness, which predominantly affects older adults in hospital. Prior to this study, the UK point prevalence of delirium was unknown. We set out to ascertain the point prevalence of delirium across UK hospitals and how this relates to adverse outcomes.

METHODS

We conducted a prospective observational study across 45 UK acute care hospitals. Older adults aged 65 years and older were screened and assessed for evidence of delirium on World Delirium Awareness Day (14th March 2018). We included patients admitted within the previous 48 h, excluding critical care admissions.

RESULTS

The point prevalence of Diagnostic and Statistical Manual on Mental Disorders, Fifth Edition (DSM-5) delirium diagnosis was 14.7% (222/1507). Delirium presence was associated with higher Clinical Frailty Scale (CFS): CFS 4-6 (frail) (OR 4.80, CI 2.63-8.74), 7-9 (very frail) (OR 9.33, CI 4.79-18.17), compared to 1-3 (fit). However, higher CFS was associated with reduced delirium recognition (7-9 compared to 1-3; OR 0.16, CI 0.04-0.77). In multivariable analyses, delirium was associated with increased length of stay (+ 3.45 days, CI 1.75-5.07) and increased mortality (OR 2.43, CI 1.44-4.09) at 1 month. Screening for delirium was associated with an increased chance of recognition (OR 5.47, CI 2.67-11.21).

CONCLUSIONS

Delirium is prevalent in older adults in UK hospitals but remains under-recognised. Frailty is strongly associated with the development of delirium, but delirium is less likely to be recognised in frail patients. The presence of delirium is associated with increased mortality and length of stay at one month. A national programme to increase screening has the potential to improve recognition.

Delirium research, education and practice

Delirium research and clinical care have seen great strides in the last decade. Age and Ageing is making freely available an online collection of 15 papers published since 2012 which provides an overview of the range of research in delirium. It covers prevention and prediction, interventions and their health economic evaluations, outcomes following delirium, and clinical application in a review of the recent SIGN guidelines. The majority of studies took place in hospitals, but we also introduce some important research about another group at high risk of delirium: care home residents. We highlight the importance of delirium education. The studies comprised a range of methodologies (systematic reviews/meta-analysis, observational studies, trials and qualitative research). The selected papers are exemplars of work that has clear clinical implications. Given that delirium affects 15-20% of hospital patients, studies or analysis of existing data with clinical relevance have the potential for enormous impact on practice and on more efficient use of healthcare resources. There is, however, still a great deal of work to be done to implement what is known to be effective, and so reduce the incidence of this distressing condition, and to support those affected: not only patients, but also families and carers, as well as staff in secondary and primary care, including care homes.

The Oslo Study of Clonidine in Elderly Patients with Delirium; LUCID: a randomised placebo-controlled trial

OBJECTIVES

The aim of this double-blinded randomised placebo-controlled trial was to investigate the efficacy of clonidine for delirium in medical inpatients greater than 65 years.

METHODS

Acutely admitted medical patients greater than 65 years with delirium or subsyndromal delirium were eligible for inclusion. Included patients were given a loading dose of either placebo or clonidine; 75 μg every third hour up to a maximum of four doses to reach steady state and further 75 μg twice daily until delirium free for 2 days, discharge or a maximum of 7 days of treatment. The primary endpoint was the trajectory of the Memorial Delirium Assessment Scale (MDAS) for the 7 days of treatment. Presence of delirium according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria and severity measured by MDAS were assessed daily until discharge or a maximum of 7 days after end of treatment.

RESULTS

Because of slower enrolment than anticipated, the study was halted early. Ten patients in each group were studied. The low recruitment rate was mainly due to the presence of multiple patient exclusion criteria for patient safety. There was no significant difference between the treatment group in the primary endpoint comparing the trajectory of MDAS for the 7 days of treatment using mixed linear models with log transformation, (P = .60). The treatment group did not have increased adverse effects.

CONCLUSIONS

No effect of clonidine for delirium was found, although the study was under powered. Further studies in less frail populations are now required.

Case finding for dementia during acute hospital admissions: a mixed-methods study exploring the impacts on patient care after discharge and costs for the English National Health Service

OBJECTIVE

Between 2012 and 2017 dementia case finding was routinely carried out on people aged 75 years and over with unplanned admissions to acute hospitals across England. The assumption was that this would lead to better planning of care and treatment for patients with dementia following discharge from hospital. However, little is known about the experiences of patients and carers or the impacts on other health services. This study explored the impact of dementia case finding on older people and their families and on their use of services.

DESIGN

Thematic content analysis was conducted on qualitative interview data and costs associated with service use were estimated. Measures included the Mini-Mental State Examination, the EuroQol quality of life scale and a modified Client Service Receipt Inventory.

SETTING

Four counties in the East of England.

PARTICIPANTS

People aged ≥75 years who had been identified by case finding during an unplanned hospital admission as warranting further investigation of possible dementia and their family carers.

RESULTS

We carried out 28 interviews, including 19 joint patient-carer(s), 5 patient only and 4 family carer interviews. Most patients and carers were unaware that memory assessments had taken place, with many families not being informed or involved in the process. Participants had a variety of views on memory testing in hospital and had concerns about how hospitals carried out assessments and communicated results. Overall, case finding did not lead to general practitioner (GP) follow-up after discharge home or lead to referral for further investigation. Few services were initiated because of dementia case finding in hospital.

CONCLUSIONS

This study shows that dementia case finding may not lead to increased GP follow-up or service provision for patients after discharge from hospital. There is a need for a more evidence-based approach to the initiation of mandatory initiatives such as case finding that inevitably consume stretched human and financial resources.

AD-8 for detection of dementia across a variety of healthcare settings

BACKGROUND

Dementia assessment often involves initial screening, using a brief tool, followed by more detailed assessment where required. The AD-8 is a short questionnaire, completed by a suitable 'informant' who knows the person well. AD-8 is designed to assess change in functional performance secondary to cognitive change.

OBJECTIVES

To determine the diagnostic accuracy of the informant-based AD-8 questionnaire, in detection of all-cause (undifferentiated) dementia in adults. Where data were available, we described the following: the diagnostic accuracy of the AD-8 at various predefined threshold scores; the diagnostic accuracy of the AD-8 for each healthcare setting and the effects of heterogeneity on the reported diagnostic accuracy of the AD-8.

SEARCH METHODS

We searched the following sources on 27 May 2014, with an update to 7 June 2018: ALOIS (Cochrane Dementia and Cognitive Improvement Group), MEDLINE (Ovid SP), Embase (Ovid SP), PsycINFO (Ovid SP), BIOSIS Previews (Thomson Reuters Web of Science), Web of Science Core Collection (includes Conference Proceedings Citation Index) (Thomson Reuters Web of Science), CINAHL (EBSCOhost) and LILACS (BIREME). We checked reference lists of relevant studies and reviews, used searches of known relevant studies in PubMed to track related articles, and contacted research groups conducting work on the AD-8 to try to find additional studies. We developed a sensitive search strategy and used standardised database subject headings as appropriate. Foreign language publications were translated.

SELECTION CRITERIA

We selected those studies which included the AD-8 to assess for the presence of dementia and where dementia diagnosis was confirmed with clinical assessment. We only included those studies where the AD-8 was used as an informant assessment. We made no exclusions in relation to healthcare setting, language of AD-8 or the AD-8 score used to define a 'test positive' case.

DATA COLLECTION AND ANALYSIS

We screened all titles generated by electronic database searches, and reviewed abstracts of potentially relevant studies. Two independent assessors checked full papers for eligibility and extracted data. We extracted data into two-by-two tables to allow calculation of accuracy metrics for individual studies. We then created summary estimates of sensitivity, specificity and likelihood ratios using the bivariate approach and plotting results in receiver operating characteristic (ROC) space. We determined quality assessment (risk of bias and applicability) using the QUADAS-2 tool.

MAIN RESULTS

From 36 papers describing AD-8 test accuracy, we included 10 papers. We utilised data from nine papers with 4045 individuals, 1107 of whom (27%) had a clinical diagnosis of dementia. Pooled analysis of seven studies, using an AD-8 informant cut-off score of two, indicated that sensitivity was 0.92 (95% confidence interval (CI) 0.86 to 0.96); specificity was 0.64 (95% CI 0.39 to 0.82); the positive likelihood ratio was 2.53 (95% CI 1.38 to 4.64); and the negative likelihood ratio was 0.12 (95% CI 0.07 to 0.21). Pooled analysis of five studies, using an AD-8 informant cut-off score of three, indicated that sensitivity was 0.91 (95% CI 0.80 to 0.96); specificity was 0.76 (95% CI 0.57 to 0.89); the positive likelihood ratio was 3.86 (95% CI 2.03 to 7.34); and the negative likelihood ratio was 0.12 (95% CI 0.06 to 0.24).Four studies were conducted in community settings; four were in secondary care (one in the acute hospital); and one study was in primary care. The AD-8 has a higher relative sensitivity (1.11, 95% CI 1.02 to 1.21), but lower relative specificity (0.51, 95% CI 0.23 to 1.09) in secondary care compared to community care settings.There was heterogeneity across the included studies. Dementia prevalence rate varied from 12% to 90% of included participants. The tool was also used in various different languages. Among all the included studies there was evidence of risk of bias. Issues included the selection of participants, conduct of index test, and flow of assessment procedures.

AUTHORS' CONCLUSIONS

The high sensitivity of the AD-8 suggests it can be used to identify adults who may benefit from further specialist assessment and diagnosis, but is not a diagnostic test in itself. This pattern of high sensitivity and lower specificity is often suited to a screening test. Test accuracy varies by setting, however data in primary care and acute hospital settings are limited. This review identified significant heterogeneity and risk of bias, which may affect the validity of its summary findings.

A Brief Informant Screening Instrument for Dementia in the ICU: The Diagnostic Accuracy of the AD8 in Critically Ill Adults Suspected of Having Pre-Existing Dementia

BACKGROUND/AIM

The diagnostic accuracy of brief informant screening instruments to detect dementia in critically ill adults is unknown. We sought to determine the diagnostic accuracy of the 2- to 3-min Ascertain Dementia 8 (AD8) completed by surrogates in detecting dementia among critically ill adults suspected of having pre-existing dementia by comparing it to the Clinical Dementia Rating Scale (CDR).

METHODS

This substudy of BRAIN-ICU included a subgroup of 75 critically ill medical/surgical patients determined to be at medium risk of having pre-existing dementia (Informant Questionnaire on Cognitive Decline in the Elderly [IQCODE] score ≥3.3). We calculated the sensitivity, specificity, positive and negative predictive values (PPV and NPV), and AUC for the standard AD8 cutoff of ≥2 versus the reference standard CDR score of ≥1 for mild dementia.

RESULTS

By the CDR, 38 patients had very mild or no dementia and 37 had mild dementia or greater. For diagnosing mild dementia, the AD8 had a sensitivity of 97% (95% CI 86-100), a specificity of 16% (6-31), a PPV of 53% (40-65), an NPV of 86% (42-100), and an AUC of 0.738 (0.626-0.850).

CONCLUSIONS

Among critically ill patients judged at risk for pre-existing dementia, the 2- to 3-min AD8 is highly sensitive and has a high NPV. These data indicate that the brief tool can serve to rule out dementia in a specific patient population.

Living at home after emergency hospital admission: prospective cohort study in older adults with and without cognitive spectrum disorder

BACKGROUND

Cognitive spectrum disorders (CSDs) are common in hospitalised older adults and associated with adverse outcomes. Their association with the maintenance of independent living has not been established. The aim was to establish the role of CSDs on the likelihood of living at home 30 days after discharge or being newly admitted to a care home.

METHODS

A prospective cohort study with routine data linkage was conducted based on admissions data from the acute medical unit of a district general hospital in Scotland. 5570 people aged ≥ 65 years admitted from a private residence who survived to discharge and received the Older Persons Routine Acute Assessment (OPRAA) during an incident emergency medical admission were included. The outcome measures were living at home, defined as a private residential address, 30 days after discharge and new care home admission at hospital discharge. Outcomes were ascertained through linkage to routine data sources.

RESULTS

Of the 5570 individuals admitted from a private residence who survived to discharge, those without a CSD were more likely to be living at home at 30 days than those with a CSD (93.4% versus 81.7%; difference 11.7%, 95%CI 9.7-13.8%). New discharge to a care home affected 236 (4.2%) of the cohort, 181 (76.7%) of whom had a CSD. Logistic regression modelling identified that all four CSD categories were associated with a reduced likelihood of living at home and an increased likelihood of discharge to a care home. Those with delirium superimposed on dementia were the least likely to be living at home (OR 0.25), followed by those with dementia (OR 0.43), then unspecified cognitive impairment (OR 0.55) and finally delirium (OR 0.57).

CONCLUSIONS

Individuals with a CSD are at significantly increased risk of not returning home after hospitalisation, and those with CSDs account for the majority of new admissions to care homes on discharge. Individuals with delirium superimposed on dementia are the most affected. We need to understand how to configure and deliver healthcare services to enable older people to remain as independent as possible for as long as possible and to ensure transitions of care are managed supportively.

Can delirium research activity impact on routine delirium recognition? A prospective cohort study

OBJECTIVE

To assess if ongoing delirium research activity within an acute admissions unit impacts on prevalent delirium recognition.

DESIGN

Prospective cohort study.

SETTING

Single-site tertiary university teaching hospital.

PARTICIPANTS

125 patients with delirium, as diagnosed by an expert using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition reference criteria, were recruited to a prospective cohort study investigating use of informant tools to detect unrecognised dementia. This study evaluated recognition of delirium and documentation of delirium by medical staff.

INTERVENTIONS

The main study followed an observational design; the intervention discussed was the implementation of this study itself.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was recognition of delirium by the admitting medical team prior to study diagnosis. Secondary outcomes included recording of or description of delirium in discharge summaries, and factors which may be associated with unrecognised delirium.

RESULTS

Delirium recognition improved between the first half (48%) and second half (71%) of recruitment (p=0.01). There was no difference in recording of delirium or description of delirium in the text of discharge summaries.

CONCLUSION

Delirium research activity can improve recognition of delirium. This has the potential to improve patient outcomes.

Diagnostic test accuracy of a novel smartphone application for the assessment of attention deficits in delirium in older hospitalised patients: a prospective cohort study protocol

Background

Delirium is a common and serious clinical syndrome which is often missed in routine clinical care. The core cognitive feature is inattention. We developed a novel bedside neuropsychological test for assessing inattention in delirium implemented on a smartphone platform (DelApp). We aim to evaluate the diagnostic performance of the DelApp in a representative cohort of older hospitalised patients.

Methods

This is a prospective study of older non-scheduled hospitalised patients (target n = 500, age ≥ 65), recruited from elderly care and acute orthopaedic wards. Exclusion criteria are: non-English speakers; severe vision or hearing impairment; photosensitive epilepsy.

A structured reference standard delirium assessment based on DSM-5 criteria will be used, which includes a cognitive test battery administered by a trained assessor (Orientation-Memory-Concentration Test, Abbreviated Mental Test-10, Delirium Rating Severity Scale-Revised-98, digit span, months and days backwards, Vigilance A’ test) and assessment of arousal (Observational Scale of Level of Arousal, Richmond Agitation Sedation Scale). Prior change in cognition will be documented using the Informant Questionnaire on Cognitive Decline in the Elderly. Patients will be categorized as delirium (with/without dementia), possible delirium, dementia, no cognitive impairment, or undetermined.

A separate assessor (blinded to diagnosis and assessments) will administer the DelApp index test within 3 h of the reference standard assessment. The DelApp comprises assessment of arousal (score 0-4) and sustained attention (score 0-6), yielding a total score between 0 and 10 (higher score = better performance). Outcomes (length of stay, mortality and discharge location) will be collected at 12 weeks.

We will evaluate a priori cutpoints derived from a previous case-control study. Measures of the accuracy of DelApp will include sensitivity, specificity, positive and negative predictive values, and area under the ROC curve. We plan repeat assessments on up to 4 occasions in a purposive subsample of 30 patients (15 delirium, 15 no delirium) to examine changes over time.

Discussion

This study evaluates the diagnostic test accuracy of a novel smartphone test for delirium in a representative cohort of older hospitalised patients, including those with dementia. DelApp has the potential to be a convenient, objective method of improving delirium assessment for older people in acute care.

Trial registration

Clinical trials.gov, NCT02590796. Registered on 29 Oct 2015. Protocol version 5, dated 25 July 2016.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0901-5) contains supplementary material, which is available to authorized users.

Performance of Electronic Prediction Rules for Prevalent Delirium at Hospital Admission

IMPORTANCE

Delirium at admission is associated with increased hospital morbidity and mortality, but it may be missed in up to 70% of cases. Use of a predictive algorithm in an electronic medical record (EMR) system could provide critical information to target assessment of those with delirium at admission.

OBJECTIVES

To develop and assess a prediction rule for delirium using 2 populations of veterans and compare this rule with previously confirmed rules.

DESIGN, SETTING, AND PARTICIPANTS

In a diagnostic study, randomly selected EMRs of hospitalized veterans from the Veterans Affairs (VA) External Peer Review Program at 118 VA medical centers with inpatient facilities were reviewed for delirium risk factors associated with the National Institute for Health and Clinical Excellence (NICE) delirium rule in a derivation cohort (October 1, 2012, to September 30, 2013) and a confirmation cohort (October 1, 2013, to March 31, 2014). Delirium within 24 hours of admission was identified using key word terms. A total of 39 377 veterans 65 years or older who were admitted to a VA medical center for congestive heart failure, acute coronary syndrome, community-acquired pneumonia, and chronic obstructive pulmonary disease were included in the study.

EXPOSURE

The EMR calculated delirium risk.

MAIN OUTCOMES AND MEASURES

Delirium at admission as identified by trained nurse reviewers was the main outcome measure. Random forest methods were used to identify accurate risk factors for prevalent delirium. A prediction rule for prevalent delirium was developed, and its diagnostic accuracy was tested in the confirmation cohort. This consolidated NICE rule was compared with previously confirmed scoring algorithms (electronic NICE and Pendlebury NICE).

RESULTS

A total of 27 625 patients were included in the derivation cohort (28 118 [92.2%] male; mean [SD] age, 75.95 [8.61] years) and 11 752 in the confirmation cohort (11 536 [98.2%] male; mean [SD] age, 75.43 [8.55] years). Delirium at admission was identified in 2343 patients (8.5%) in the derivation cohort and 882 patients (7.0%) in the confirmation cohort. Modeling techniques identified cognitive impairment, infection, sodium level, and age of 80 years or older as the dominant risk factors. The consolidated NICE rule (area under the receiver operating characteristic [AUROC] curve, 0.91; 95% CI, 0.91-0.92; P < .001) had significantly higher discriminatory function than the eNICE rule (AUROC curve, 0.81; 95% CI, 0.80-0.82; P < .001) or Pendlebury NICE rule (AUROC curve, 0.87; 95% CI, 0.86-0.88; P < .001). These findings were confirmed in the confirmation cohort.

CONCLUSIONS AND RELEVANCE

This analysis identified preexisting cognitive impairment, infection, sodium level, and age of 80 years or older as delirium screening targets. Use of this algorithm in an EMR system could direct clinical assessment efforts to patients with delirium at admission.

Acetylcholinesterase Activity Measurement and Clinical Features of Delirium

AIMS

Cholinergic deficiency is commonly implicated in the pathophysiology of delirium. We aimed to investigate the relationship between directly measured serum acetylcholinesterase (AChE) activity and (1) clinical features of delirium and (2) outcomes among older hospital patients with delirium.

METHODS

Hospitalised patients with delirium were recruited, and delirium motor subtype, severity and duration of delirium were measured. Serum AChE activity was measured using a colorimetric assay.

RESULTS

The mean AChE activity for the whole sample was 2.46 μmol/μL/min (standard deviation 1.75). Higher AChE activity was associated with increased likelihood of hypoactive delirium rather than the hyperactive or mixed subtype (odds ratio 1.98, 95% confidence interval 1.10-3.59).

CONCLUSION

Higher AChE activity was associated with hypoactive delirium but did not predict outcomes. Simple enhancement of cholinergic neurotransmission may not be sufficient to treat delirium.

Dementia case-finding in hospitals: a qualitative study exploring the views of healthcare professionals in English primary care and secondary care

OBJECTIVES

In 2012-2013, the English National Health Service mandated hospitals to conduct systematic case-finding of people with dementia among older people with unplanned admissions. The method was not defined. The aim of this study was to understand current approaches to dementia case-finding in acute hospitals in England and explore the views of healthcare professionals on perceived benefits and challenges.

DESIGN

Qualitative study involving interviews, focus groups and thematic content analysis.

SETTING

Primary care and secondary care across six counties in the East of England.

PARTICIPANTS

Hospital staff involved in dementia case-finding and primary care staff in the catchment areas of those hospitals.

RESULTS

We recruited 23 hospital staff and 36 primary care staff, including 30 general practitioners (GPs). Analysis resulted in three themes: (1) lack of consistent approaches in case-finding processes, (2) barriers between primary care and secondary care which impact on case-finding outcomes and (3) perceptions of rationale, aims and impacts of case-finding. The study shows that there were variations in how well hospitals recorded and reported outcomes to GPs. Barriers between primary care and secondary care, including GPs' lack of access to hospital investigations and lack of clarity about roles and responsibilities, impacted case-finding outcomes. Staff in secondary care were more positive about the initiative than primary care staff, and there were conflicting priorities for primary care and secondary care regarding case-finding.

CONCLUSIONS

The study suggests a more evidence-based approach was needed to justify approaches to dementia case-finding. Information communicated to primary care from hospitals needs to be comprehensive, appropriate and consistent before GPs can effectively plan further investigation, treatment or care. Follow-up in primary care further requires access to options for postdiagnostic support. There is a need to evaluate the outcomes for patients and the economic impact on health and care services across settings.

Validation of the 6-Item Cognitive Impairment Test and the 4AT test for combined delirium and dementia screening in older Emergency Department attendees

Background

screening for cognitive impairment in Emergency Department (ED) requires short, reliable tools.

Objective

to validate the 4AT and 6-Item Cognitive Impairment Test (6-CIT) for ED dementia and delirium screening.

Design

diagnostic accuracy study.

Setting/subjects

attendees aged ≥70 years in a tertiary care hospital’s ED.

Methods

trained researchers assessed participants using the Standardised Mini Mental State Examination, Delirium Rating Scale-Revised 98 and Informant Questionnaire on Cognitive Decline in the Elderly, informing ultimate expert diagnosis using Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria for dementia and delirium (reference standards). Another researcher blindly screened each participant, within 3 h, using index tests 4AT and 6-CIT.

Result

of 419 participants (median age 77 years), 15.2% had delirium and 21.5% had dementia. For delirium detection, 4AT had positive predictive value (PPV) 0.68 (95% confidence intervals: 0.58–0.79) and negative predictive value (NPV) 0.99 (0.97–1.00). At a pre-specified 9/10 cut-off (9 is normal), 6-CIT had PPV 0.35 (0.27–0.44) and NPV 0.98 (0.95–0.99).

Importantly, 52% of participants had no family present. A novel algorithm for scoring 4AT item 4 where collateral history is unavailable (score 4 if items 2–3 score ≥1; score 0 if items 1–3 score is 0) proved reliable; PPV 0.65 (0.54–0.76) and NPV 0.99 (0.97–1.00). For dementia detection, 4AT had PPV 0.39 (0.32–0.46) and NPV 0.94 (0.89–0.96); 6-CIT had PPV 0.46 (0.37–0.55) and NPV 0.94 (0.90–0.97).

Conclusion

6-CIT and 4AT accurately exclude delirium and dementia in older ED attendees. 6-CIT does not require collateral history but has lower PPV for delirium.

Perioperative hemodynamics and risk for delirium and new onset dementia in hip fracture patients; A prospective follow-up study

BACKGROUND

Delirium is common in hip fracture patients and many risk factors have been identified. Controversy exists regarding the possible impact of intraoperative control of blood pressure upon acute (delirium) and long term (dementia) cognitive decline. We explored possible associations between perioperative hemodynamic changes, use of vasopressor drugs, risk of delirium and risk of new-onset dementia.

METHODS

Prospective follow-up study of 696 hip fracture patients, assessed for delirium pre- and postoperatively, using the Confusion Assessment Method. Pre-fracture cognitive function was assessed using the Informant Questionnaire of Cognitive Decline in the Elderly and by consensus diagnosis. The presence of new-onset dementia was determined at follow-up evaluation at six or twelve months after surgery. Blood pressure was recorded at admission, perioperatively and postoperatively.

RESULTS

Preoperative delirium was present in 149 of 536 (28%) assessable patients, and 124 of 387 (32%) developed delirium postoperatively (incident delirium). The following risk factors for incident delirium in patients without pre-fracture cognitive impairment were identified: low body mass index, low level of functioning, severity of physical illness, and receipt of ≥ 2 blood transfusions. New-onset dementia was diagnosed at follow-up in 26 of 213 (12%) patients, associated with severity of physical illness, delirium, receipt of vasopressor drugs perioperatively and high mean arterial pressure postoperatively.

CONCLUSION

Risk factors for incident delirium seem to differ according to pre-fracture cognitive status. The use of vasopressors during surgery and/or postoperative hypertension is associated with new-onset dementia after hip fracture.

Challenges and opportunities in understanding dementia and delirium in the acute hospital

In an Essay, Andrew Jackson and colleagues discuss challenges in the diagnosis and management of older people with dementia and delirium in acute hospitals.

Delirium: a guide for the general physician

Delirium describes a sudden onset change in mental status of fluctuating course. This is a state of altered consciousness characterised chiefly by inattention or lack of arousal, but can also include new impairment of language, perception and behaviour. Certain predisposing factors can make an individual more susceptible to delirium in the face of a stressor. Stressors include direct insults to the brain, insults peripheral to the brain or external changes in the environment of an individual. Delirium is varied in its presentation, and can be categorised by the psychomotor profile as: hyperactive type (overly vigilant, agitated, often wandersome), hypoactive type (sedate or withdrawn) or mixed types.

Delirium: a guide for the general physician

Delirium describes a sudden onset change in mental status of fluctuating course. This is a state of altered consciousness characterised chiefly by inattention or lack of arousal, but can also include new impairment of language, perception and behaviour. Certain predisposing factors can make an individual more susceptible to delirium in the face of a stressor. Stressors include direct insults to the brain, insults peripheral to the brain or external changes in the environment of an individual. Delirium is varied in its presentation, and can be categorised by the psychomotor profile as: hyperactive type (overly vigilant, agitated, often wandersome), hypoactive type (sedate or withdrawn) or mixed types.

Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for the early diagnosis of dementia across a variety of healthcare settings

BACKGROUND

The Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) is a structured interview based on informant responses that is used to assess for possible dementia. IQCODE has been used for retrospective or contemporaneous assessment of cognitive decline. There is considerable interest in tests that may identify those at future risk of developing dementia. Assessing a population free of dementia for the prospective development of dementia is an approach often used in studies of dementia biomarkers. In theory, questionnaire-based assessments, such as IQCODE, could be used in a similar way, assessing for dementia that is diagnosed on a later (delayed) assessment.

OBJECTIVES

To determine the diagnostic accuracy of IQCODE in a population free from dementia for the delayed diagnosis of dementia (test accuracy with delayed verification study design).

SEARCH METHODS

We searched these sources on 16 January 2016: ALOIS (Cochrane Dementia and Cognitive Improvement Group), MEDLINE Ovid SP, Embase Ovid SP, PsycINFO Ovid SP, BIOSIS Previews on Thomson Reuters Web of Science, Web of Science Core Collection (includes Conference Proceedings Citation Index) on Thomson Reuters Web of Science, CINAHL EBSCOhost, and LILACS BIREME. We also searched sources specific to diagnostic test accuracy: MEDION (Universities of Maastricht and Leuven); DARE (Database of Abstracts of Reviews of Effects, in the Cochrane Library); HTA Database (Health Technology Assessment Database, in the Cochrane Library), and ARIF (Birmingham University). We checked reference lists of included studies and reviews, used searches of included studies in PubMed to track related articles, and contacted research groups conducting work on IQCODE for dementia diagnosis to try to find additional studies. We developed a sensitive search strategy; search terms were designed to cover key concepts using several different approaches run in parallel, and included terms relating to cognitive tests, cognitive screening, and dementia. We used standardised database subject headings, such as MeSH terms (in MEDLINE) and other standardised headings (controlled vocabulary) in other databases, as appropriate.

SELECTION CRITERIA

We selected studies that included a population free from dementia at baseline, who were assessed with the IQCODE and subsequently assessed for the development of dementia over time. The implication was that at the time of testing, the individual had a cognitive problem sufficient to result in an abnormal IQCODE score (defined by the study authors), but not yet meeting dementia diagnostic criteria.

DATA COLLECTION AND ANALYSIS

We screened all titles generated by the electronic database searches, and reviewed abstracts of all potentially relevant studies. Two assessors independently checked the full papers for eligibility and extracted data. We determined quality assessment (risk of bias and applicability) using the QUADAS-2 tool, and reported quality using the STARDdem tool.

MAIN RESULTS

From 85 papers describing IQCODE, we included three papers, representing data from 626 individuals. Of this total, 22% (N = 135/626) were excluded because of prevalent dementia. There was substantial attrition; 47% (N = 295) of the study population received reference standard assessment at first follow-up (three to six months) and 28% (N = 174) received reference standard assessment at final follow-up (one to three years). Prevalence of dementia ranged from 12% to 26% at first follow-up and 16% to 35% at final follow-up.The three studies were considered to be too heterogenous to combine, so we did not perform meta-analyses to describe summary estimates of interest. Included patients were poststroke (two papers) and hip fracture (one paper). The IQCODE was used at three thresholds of positivity (higher than 3.0, higher than 3.12 and higher than 3.3) to predict those at risk of a future diagnosis of dementia. Using a cut-off of 3.0, IQCODE had a sensitivity of 0.75 (95%CI 0.51 to 0.91) and a specificity of 0.46 (95%CI 0.34 to 0.59) at one year following stroke. Using a cut-off of 3.12, the IQCODE had a sensitivity of 0.80 (95%CI 0.44 to 0.97) and specificity of 0.53 (95C%CI 0.41 to 0.65) for the clinical diagnosis of dementia at six months after hip fracture. Using a cut-off of 3.3, the IQCODE had a sensitivity of 0.84 (95%CI 0.68 to 0.94) and a specificity of 0.87 (95%CI 0.76 to 0.94) for the clinical diagnosis of dementia at one year after stroke.In generaI, the IQCODE was sensitive for identification of those who would develop dementia, but lacked specificity. Methods for both excluding prevalent dementia at baseline and assessing for the development of dementia were varied, and had the potential to introduce bias.

AUTHORS' CONCLUSIONS

Included studies were heterogenous, recruited from specialist settings, and had potential biases. The studies identified did not allow us to make specific recommendations on the use of the IQCODE for the future diagnosis of dementia in clinical practice. The included studies highlighted the challenges of delayed verification dementia research, with issues around prevalent dementia assessment, loss to follow-up over time, and test non-completion potentially limiting the studies. Future research should recognise these issues and have explicit protocols for dealing with them.

Delirium is not associated with anticholinergic burden or polypharmacy in older patients on admission to an acute hospital: an observational case control study

Background

Older people are commonly prescribed multiple medications, including medications with anticholinergic effects. Polypharmacy and anticholinergic medications may be risk factors for the development of delirium.

Methods

Patients from a medical admission unit who were over 70, with DSM-IV diagnosed delirium and patients without delirium, were investigated. Number of drugs prescribed on admission and anticholinergic burden using two scales (the Anticholinergic Cognitive Burden Scale [ACB] and the Anticholinergic Drug Scale [ADS]) were recorded from electronic prescribing records. The relationship and predictive ability of these were explored.

Results

The sample included 125 patients with DSM-IV diagnosed delirium and 122 patients without delirium. The mean age of the sample was 84.0 years. The median number of drugs prescribed was 7: 79.8 % were prescribed ≥5 drugs and 29.0 % ≥10 drugs. The median ACB score was 1 and the median ADS score was 1.5. 73.4 % of patients had an ACB score of ≥1 and 73.0 % had a ADS score ≥1. There was no association between: number of drugs prescribed, rate of polypharmacy, rate of excessive polypharmacy, ACB score and ADS score, and a diagnosis of delirium on admission. Only acetylcholinesterase inhibitor use predicted delirium (OR 3.86, p = 0.04) and the number of drugs prescribed was negatively correlated with age (spearman rho = −0.18, p = 0.006).

Conclusion

Neither number of drugs prescribed, polypharmacy or anticholinergic burden were associated with delirium on admission, questioning the clinical usefulness of anticholinergic drug scales. Further research is needed to unpick fully the relationship between, drugs, anticholinergic burden, age, and prevalent delirium in older patients and whether there is any role for these scales in clinical practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-016-0336-9) contains supplementary material, which is available to authorized users.