Association between components of the delirium syndrome and outcomes in hospitalised adults: a systematic review and meta-analysis.

BACKGROUND: Delirium is a heterogeneous syndrome with inattention as the core feature. There is considerable variation in the presence and degree of other symptom domains such as altered arousal, psychotic features and global cognitive dysfunction. Delirium is independently associated with increased mortality, but it is unclear whether individual symptom domains of delirium have prognostic importance. We conducted a systematic review and meta-analysis of studies in hospitalised adults in general settings to identify the relationship between symptom domains of delirium and outcomes. (PROSPERO: CRD42018093935). METHODS: We searched MEDLINE, EMBASE, PsycINFO, CINAHL, clinicaltrials.gov and the Cochrane Central Register of Controlled Trials from inception to November 2019. We included studies of hospitalised adults that reported associations between symptom domains of delirium and 30-day mortality (primary outcome), and other outcomes including mortality at other time points, length of stay, and dementia. Reviewer pairs independently screened articles, extracted data, and assessed risk of bias (Risk of Bias Assessment tool for Non-randomized Studies) and quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation framework. We performed random-effects meta-analyses stratified by delirium domain where possible. RESULTS: From 7092 citations we included 6 studies (6002 patients, 1112 with delirium). Higher mortality (ranging from in-hospital to follow-up beyond 12 months) was associated with altered arousal (pooled Odds Ratio (OR) 2.80, 95% Confidence Interval (CI) 2.33-3.37; moderate-quality evidence), inattention (pooled OR 2.57, 95% CI 1.74-3.80; low-quality evidence), and in single studies with disorientation, memory deficits and disorganised thoughts. Risk of bias varied across studies but was moderate-to-high overall, mainly due to selection bias, lack of blinding of assessments and unclear risk of selective outcome reporting. We found no studies on the association between psychotic features, visuospatial deficits or affective disturbances in delirium and outcomes, or studies reporting non-mortality outcomes. CONCLUSIONS: Few studies have related symptom domains of delirium to outcomes, but the available evidence suggests that altered arousal and inattention in delirium are associated with higher mortality than normal arousal and attention in people with or without delirium. Measurable symptom domains of delirium may have value in predicting survival and stratifying patients for treatment. We recommend that future delirium studies report outcomes by symptom domain

Stress in childhood, adolescence and early adulthood, and cortisol levels in older age

The glucocorticoid hypothesis suggests that overexposure to stress may cause permanent upregulation of cortisol. Stress in youth may therefore influence cortisol levels even in older age. Using data from the 6-Day Sample, we investigated the effects of high stress in childhood, adolescence and early adulthood ¬� as well as individual variables contributing to these measures; parental loss, social deprivation, school and home moves, illness, divorce and job instability � upon cortisol levels at age 77 years. Waking, waking+45min (peak) and evening salivary cortisol samples were collected from 159 participants, and the 150 who were not using steroid medications were included in this study. After correcting for multiple comparisons, the only significant association was between early-adulthood job instability and later-life peak cortisol levels. After excluding participants with dementia or possible mild cognitive impairment, early-adulthood high stress showed significant associations with lower evening and mean cortisol levels, suggesting downregulation by stress, but these results did not survive correction for multiple comparisons. Overall, our results do not provide strong evidence of a relationship between stress in youth and later-life cortisol levels, but do suggest that some more long-term stressors, such as job instability, may indeed produce lasting upregulation of cortisol, persisting into the mid-to-late seventies

Detecting delirium superimposed on dementia: diagnostic accuracy of a simple combined arousal and attention testing procedure

Detecting delirium superimposed on dementia (DSD) can be challenging because assessment partly relies on cognitive tests that may be abnormal in both conditions. We hypothesized that a combined arousal and attention testing procedure would accurately detect DSD. Patients aged ≥70 years were recruited from five hospitals across Europe. Delirium was diagnosed by physicians using DSM-5 criteria using information from nurses, carers, and medical records. Dementia was ascertained by the Informant Questionnaire on Cognitive Decline in the Elderly. Arousal was measured using the Observational Scale of Level of Arousal (OSLA), which assesses eye opening, eye contact, posture, movement, and communication. Attention was measured by participants signaling each time an “A” was heard when “S-A-V-E-A-H-A-A-R-T” was read out. The sample included 114 persons (mean age 82 years (SD 7); 54% women). Dementia alone was present in 25% (n = 28), delirium alone in 18% (n = 21), DSD in 27% (n = 31), and neither in 30% (n = 34). Arousal and attention was assessed in n = 109 (96%). Using OSLA, 83% participants were correctly identified as having delirium (sensitivity 85%, specificity 82%, AUROC 0.92). The attention task correctly classified 76% of participants with delirium (sensitivity 90%, specificity 64%, AUROC 0.80). Combining scores correctly classified 91% of participants with delirium (sensitivity 84%, specificity 92%, AUROC 0.94). Diagnostic accuracy remained high in the subgroup with dementia (93% correctly classified, sensitivity 94%, specificity 92%, AUROC 0.98). This combined arousal–attention assessment to detect DSD was brief yet had high diagnostic accuracy. Such an approach could have clinical utility for diagnosing DSD

A systematic review of studies reporting on neuropsychological and functional domains used for assessment of recovery from delirium in acute hospital patients

Objectives: Assessing for recovery in delirium is essential in guiding ongoing investigation and treatment. Yet, there is little scrutiny and no research or clinical consensus on how recovery should be measured. We reviewed studies which used tests of neuropsychological domains and functional ability to track recovery of delirium longitudinally in acute hospital settings. / Methods/Design: We systematically searched databases (MEDLINE, PsycInfo, CINAHL, Embase, ClinicalTrials.gov, Cochrane Central Register of Controlled Trials), from inception to October 14th, 2022. Inclusion criteria were: adult acute hospital patients (≥18 years) diagnosed with delirium by a validated tool; 1+ repeat assessment using an assessment tool measuring domains of delirium/functional recovery ≤7 days from baseline. Two reviewers independently screened articles, performed data extraction, and assessed risk of bias. A narrative data synthesis was completed. / Results: From 6533 screened citations, we included 39 papers (reporting 32 studies), with 2370 participants with delirium. Studies reported 21 tools with an average of four repeat assessments including baseline (range 2–10 assessments within ≤7 days), measuring 15 specific domains. General cognition, functional ability, arousal, attention and psychotic features were most commonly assessed for longitudinal change. Risk of bias was moderate to high for most studies. / Conclusions: There was no standard approach for tracking change in specific domains of delirium. The methodological heterogeneity of studies was too high to draw firm conclusions on the effectiveness of assessment tools to measure delirium recovery. This highlights the need for standardised methods for assessing recovery from delirium

Increasing delirium skills at the front door: results from a repeated survey on delirium knowledge and attitudes

Background: delirium is under-recognised in comparison to other common and serious acute disorders. A 2006 survey of UK junior doctors (not undertaking specialist training) identified poor knowledge of the diagnostic criteria and treatment of delirium. We hypothesised that increased prominence accorded to delirium in the form of national initiatives and guidelines may have had an impact on understanding among junior doctors. Objective: we repeated a multi-centre survey of knowledge of and attitudes to delirium in junior doctors (not undertaking specialist training) assessing unselected acute medical presentations (the ‘medical take’). Design: questionnaire-based survey in 48 acute hospitals in UK and Ireland. Methods: we used questionnaires designed to test understanding of delirium, including prevalence, knowledge of the DSMIV diagnostic criteria, use of specific screening tools, association with adverse outcomes and pharmacological management. Results: one thousand two hundred and fifteen trainee physicians participated. Compared with the 2006 cohort, improvements were seen in 9 of 17 knowledge-based questions and overall score improved in the 2013 cohort. Nonetheless, significant deficits in knowledge, particularly for the diagnostic criteria for delirium, remained. Conclusions: despite improvements in some aspects of delirium knowledge, the diagnostic criteria for delirium remain poorly understood. Challenges remain in ensuring adequate training for junior doctors in delirium

Association of Delirium With Cognitive Decline in Late Life: A Neuropathologic Study of 3 Population-Based Cohort Studies

Importance: Delirium is associated with accelerated cognitive decline. The pathologic substrates of this association are not yet known, that is, whether they are the same as those associated with dementia, are independent, or are interrelated. Objective: To examine whether the accelerated cognitive decline observed after delirium is independent of the pathologic processes of classic dementia. Design, Setting, and Participants: Harmonized data from 987 individual brain donors from 3 observational cohort studies with population-based sampling (Vantaa 85+, Cambridge City Over-75s Cohort, Cognitive Function and Ageing Study) performed from January 1, 1985, through December 31, 2011, with a median follow-up of 5.2 years until death, were used in this study. Neuropathologic assessments were performed with investigators masked to clinical data. Data analysis was performed from January 1, 2012, through December 31, 2013. Clinical characteristics of brain donors were not different from the rest of the cohort. Outcome ascertainment was complete given that the participants were brain donors. Exposures: Delirium (never vs ever) and pathologic burden of neurofibrillary tangles, amyloid plaques, vascular lesions, and Lewy bodies. Effects modeled using random-effects linear regression and interactions between delirium and pathologic burden were assessed. Outcomes: Change in Mini-Mental State Examination (MMSE) scores during the 6 years before death. Results: There were 987 participants (290 from Vantaa 85+, 241 from the Cambridge City Over-75s Cohort, and 456 from the Cognitive Function and Ageing Study) with neuropathologic data; mean (SD) age at death was 90 (6.4) years, including 682 women (69%). The mean MMSE score 6 years before death was 24.7 points. The 279 individuals with delirium (75% women) had worse initial scores (−2.8 points; 95% CI, −4.5 to −1.0; P < .001). Cognitive decline attributable to delirium was −0.37 MMSE points per year (95% CI, −0.60 to −0.13; P < .001). Decline attributable to the pathologic processes of dementia was −0.39 MMSE points per year (95% CI, −0.57 to −0.22; P < .001). However, the combination of delirium and the pathologic processes of dementia resulted in the greatest decline, in which the interaction contributed an additional −0.16 MMSE points per year (95% CI, −0.29 to −0.03; P = .01). The multiplicative nature of these variables resulted in individuals with delirium and the pathologic processes of dementia declining 0.72 MMSE points per year faster than age-, sex-, and educational level–matched controls. Conclusions and Relevance: Delirium in the presence of the pathologic processes of dementia is associated with accelerated cognitive decline beyond that expected for delirium or the pathologic process itself. These findings suggest that additional unmeasured pathologic processes specifically relate to delirium. Age-related cognitive decline has many contributors, and these findings at the population level support a role for delirium acting independently and multiplicatively to the pathologic processes of classic dementia

ABCD Neurocognitive Prediction Challenge 2019: Predicting individual fluid intelligence scores from structural MRI using probabilistic segmentation and kernel ridge regression

We applied several regression and deep learning methods to predict fluid intelligence scores from T1-weighted MRI scans as part of the ABCD Neurocognitive Prediction Challenge (ABCD-NP-Challenge) 2019. We used voxel intensities and probabilistic tissue-type labels derived from these as features to train the models. The best predictive performance (lowest mean-squared error) came from Kernel Ridge Regression (KRR; $\lambda=10$), which produced a mean-squared error of 69.7204 on the validation set and 92.1298 on the test set. This placed our group in the fifth position on the validation leader board and first place on the final (test) leader board.Comment: Winning entry in the ABCD Neurocognitive Prediction Challenge at MICCAI 2019. 7 pages plus references, 3 figures, 1 tabl

Perivascular Spaces Segmentation in Brain MRI Using Optimal 3D Filtering

Perivascular Spaces (PVS) are a recently recognised feature of Small Vessel Disease (SVD), also indicating neuroinflammation, and are an important part of the brain's circulation and glymphatic drainage system. Quantitative analysis of PVS on Magnetic Resonance Images (MRI) is important for understanding their relationship with neurological diseases. In this work, we propose a segmentation technique based on the 3D Frangi filtering for extraction of PVS from MRI. Based on prior knowledge from neuroradiological ratings of PVS, we used ordered logit models to optimise Frangi filter parameters in response to the variability in the scanner's parameters and study protocols. We optimized and validated our proposed models on two independent cohorts, a dementia sample (N=20) and patients who previously had mild to moderate stroke (N=48). Results demonstrate the robustness and generalisability of our segmentation method. Segmentation-based PVS burden estimates correlated with neuroradiological assessments (Spearman's $\rho$ = 0.74, p $<$ 0.001), suggesting the great potential of our proposed metho

A rehabilitation intervention to improve recovery after an episode of delirium in adults over 65 years (RecoverED): study protocol for a multi-centre, single-arm feasibility study

Background: Delirium affects over 20% of all hospitalised older adults. Delirium is associated with a number of adverse outcomes following hospital admission including cognitive decline, anxiety and depression, increased mortality and care needs. Previous research has addressed prevention of delirium in hospitals and care homes, and there are guidelines on short-term treatment of delirium during admission. However, no studies have addressed the problem of longer-term recovery after delirium and it is currently unknown whether interventions to improve recovery after delirium are effective and cost-effective. The primary objective of this feasibility study is to test a new, theory-informed rehabilitation intervention (RecoverED) in older adults delivered following a hospital admission complicated by delirium to determine whether (a) the intervention is acceptable to individuals with delirium and (b) a definitive trial and parallel economic evaluation of the intervention are feasible. Methods: The study is a multi-centre, single-arm feasibility study of a rehabilitation intervention with an embedded process evaluation. Sixty participants with delirium (aged > 65 years old) and carer pairs will be recruited from six NHS acute hospitals across the UK. All pairs will be offered the intervention, with follow-up assessments conducted at 3 months and 6 months post-discharge home. The intervention will be delivered in participants’ own homes by therapists and rehabilitation support workers for up to 10 intervention sessions over 12 weeks. The intervention will be tailored to individual needs, and the chosen intervention plan and goals will be discussed and agreed with participants and carers. Quantitative data on reach, retention, fidelity and dose will be collected and summarised using descriptive statistics. The feasibility outcomes that will be used to determine whether the study meets the criteria for progression to a definitive randomised controlled trial (RCT) include recruitment, delivery of the intervention, retention, data collection and acceptability of outcome measures. Acceptability of the intervention will be assessed using in-depth, semi-structured qualitative interviews with participants and healthcare professionals. Discussion: Findings will inform the design of a pragmatic multi-centre RCT of the effectiveness and cost-effectiveness of the RecoverED intervention for helping the longer-term recovery of people with delirium compared to usual care. Trial registration: The feasibility study was registered: ISRCTN1567657