Hospitalisation without delirium is not associated with cognitive decline in a population-based sample of older people-results from a nested, longitudinal cohort study

Delirium Prevention in Early Rehabilitation During Acute Hospitalization and Implementation of Programs Specifically Tailored to Older Patients with Cognitive Impairment: A Scoping Review with Meta-Analysis

BACKGROUND

No systematic review on delirium prevention within early, hospital-based rehabilitation on implementation of approaches specifically tailored for patients with cognitive impairment (PwCI), such as Alzheimer's disease or vascular dementia, has been published despite the high relevance of specific medical care in this vulnerable population.

OBJECTIVE

To document design and effectiveness of delirium prevention programs by early rehabilitation during acute, hospital-based medical care and implementation of programs specifically tailored to PwCI.

METHODS

In a three-step approach, we first identified published systematic reviews of hospital-based, early rehabilitation interventions for older persons (>65 years) in relevant databases. In a second step, we screened each single trial of included reviews according to predefined inclusion criteria. In a third step, we analyzed studies with focus on delirium prevention.

RESULTS

Among n = 25 studies identified, almost all intervention programs did not specifically target cognitive impairment (CI). Interventions were heterogeneous (modules: n = 2-19); almost all study samples were mixed/unspecified for cognitive status with more affected patients excluded. Only one study exclusively included delirium patients, and only one included CI patients. Results of random effect meta-analysis showed significant effects of generic programs to reduce delirium incidence during hospitalization by 41% (p < 0.001, odds ratio, 95% confidence interval: 0.59 [0.49, 0.71] with modest heterogeneity (I2: 30%).

CONCLUSIONS

Study results document a lack of implementation for delirium prevention programs specifically tailored to PwCI by early, hospital-based rehabilitation. Specifying existing rehab concepts or augmenting them by CI-specific modules may help to develop, optimize, and implement innovative delirium prevention in PwCI in acute medical care.

nlive: an R package to facilitate the application of the sigmoidal and random changepoint mixed models

BACKGROUND

The use of mixed effect models with a specific functional form such as the Sigmoidal Mixed Model and the Piecewise Mixed Model (or Changepoint Mixed Model) with abrupt or smooth random change allows the interpretation of the defined parameters to understand longitudinal trajectories. Currently, there are no interface R packages that can easily fit the Sigmoidal Mixed Model allowing the inclusion of covariates or incorporating recent developments to fit the Piecewise Mixed Model with random change.

RESULTS

To facilitate the modeling of the Sigmoidal Mixed Model, and Piecewise Mixed Model with abrupt or smooth random change, we have created an R package called nlive. All needed pieces such as functions, covariance matrices, and initials generation were programmed. The package was implemented with recent developments such as the polynomial smooth transition of the piecewise mixed model with improved properties over Bacon-Watts, and the stochastic approximation expectation-maximization (SAEM) for efficient estimation. It was designed to help interpretation of the output by providing features such as annotated output, warnings, and graphs. Functionality, including time and convergence, was tested using simulations. We provided a data example to illustrate the package use and output features and interpretation. The package implemented in the R software is available from the Comprehensive R Archive Network (CRAN) at https://CRAN.R-project.org/package=nlive .

CONCLUSIONS

The nlive package for R fits the Sigmoidal Mixed Model and the Piecewise Mixed: abrupt and smooth. The nlive allows fitting these models with only five mandatory arguments that are intuitive enough to the less sophisticated users.

Hospital-Diagnosed Infections, Autoimmune Diseases, and Subsequent Dementia Incidence

Importance

Systemic inflammation has been suggested to explain reported associations between infections and dementia. Associations between autoimmune diseases and dementia also suggest a role for peripheral systemic inflammation.

Objective

To investigate the associations of infections and autoimmune diseases with subsequent dementia incidence and to explore potential shared signals presented by the immune system in the 2 conditions.

Design, Setting, and Participants

This nationwide, population-based, registry-based cohort study was conducted between 1978 and 2018 (40-year study period). All Danish residents born 1928 to 1953, alive and in Denmark on January 1, 1978, and at age 65 years were included. Persons with prior registered dementia and those with HIV infections were excluded. Data were analyzed between May 2022 and January 2023.

Exposures

Hospital-diagnosed infections and autoimmune diseases.

Main Outcomes and Measures

All-cause dementia, defined as the date of a first registered dementia diagnosis after age 65 years in the registries. Poisson regression with person-years at risk as an offset variable was used to analyze time to first dementia diagnosis.

Results

A total of 1 493 896 individuals (763 987 women [51%]) were followed for 14 093 303 person-years (677 147 [45%] with infections, 127 721 [9%] with autoimmune diseases, and 75 543 [5%] with dementia). Among individuals with infections, 343 504 (51%) were men, whereas among those with autoimmune diseases, 77 466 (61%) were women. The dementia incidence rate ratio (IRR) following any infection was 1.49 (95% CI, 1.47-1.52) and increased along with increasing numbers of infections in a dose-dependent manner. Dementia rates were increased for all infection sites in the short term, but not always in the long term. The dementia IRR following any autoimmune disease was 1.04 (95% CI, 1.01-1.06), but no dose-dependent increase was observed, and only a few autoimmune conditions showed increased IRRs for dementia.

Conclusions and Relevance

These findings may point toward a role for infection-specific processes in the development of dementia, rather than general systemic inflammation, as previously hypothesized. Assessing these 2 conditions in a single setting may allow for additional insights into their roles in dementia and for hypotheses on possible underlying mechanisms.

Delirium, neurofilament light chain, and progressive cognitive impairment: analysis of a prospective Norwegian population-based cohort

BACKGROUND

Previous population-based, longitudinal studies have shown that delirium is associated with an increased risk of dementia and cognitive decline. However, the underlying biological mechanisms are largely unknown. We aimed to assess the effects of delirium on both cognitive trajectories and any neuronal injury, measured via neurofilament light chain (NfL).

METHODS

In this analysis of a prospective, 2-year follow-up, cohort study of participants aged 65 years or older living in Sandefjord municipality, Norway, we included cohort participants who were receiving domiciliary care services at least once per week between May 12, 2015, and July 8, 2016. Individuals with a life expectancy of less than 1 week, with Lewy body dementia, with psychiatric illness (except dementia), or for whom substance misuse was the principal indication for domiciliary services were excluded. Participants had a comprehensive assessment at 6-month intervals for 2 years, which included the Montreal Cognitive Assessment (MoCA) and a blood sample for NfL to measure neuronal injury. All information on clinical diagnoses and medications were cross-referenced with medical records. During any acute change in mental status or hospitalisation (ie, admission to hospital), participants were assessed once per day for delirium with Diagnostic and Statistical Manual of Mental Disorders, fifth edition criteria. We also measured NfL from blood samples taken from participants who were acutely hospitalised.

FINDINGS

Between May 12, 2015, and July 8, 2016, 210 participants were eligible for inclusion and assessed at baseline (138 [66%] of whom were female and 72 [34%] of whom were male), 203 completed cognitive assessment, and 141 were followed up for 2 years. 160 (76%) of 210 had moderate or severe frailty and 112 (53%) were living with dementia. During the 2-year follow-up, 89 (42%) of 210 participants were diagnosed with one or more episodes of delirium. Incident delirium was independently associated with a decrease in MoCA score at the next 6-month follow-up, even after adjustment for age, sex, education, previous MoCA score, and frailty (adjusted mean difference -1·5, 95% CI -2·9 to -0·1). We found an interaction between previous MoCA score and delirium (β -0·254, 95% CI -0·441 to -0·066, p=0·010), with the largest decline being observed in people with better baseline cognition. Participants with delirium and good previous cognitive function and participants with a high peak concentration of NfL during any hospitalisation had increased NfL at the next 6-month follow-up. Mediation analyses showed independent pathways from previous MoCA score to follow-up MoCA score with contributions from incident delirium (-1·7, 95% CI -2·8 to -0·6) and from previous NfL to follow-up MoCA score with contributions from acute NfL concentrations (-1·8, -2·5 to -1·1). Delirium was directly linked with a predicted value of 1·2 pg/mL (95% CI 1·02 to 1·40, p=0·029) increase in NfL.

INTERPRETATION

In people aged 65 years or older, an episode of delirium was associated with a decline in MoCA score. Greater neuronal injury during acute illness and delirium, measured by NfL, was associated with greater cognitive decline. For clinicians, our finding of delirium associated with both signs of acute neuronal injury, measured via NfL, and cognitive decline is important regarding the risk of long-term cognitive deterioration and to acknowledge that delirium is harmful for the brain.

FUNDING

South-Eastern Norway Health Authorities, Old Age Psychiatry Research Network, Telemark Hospital Trust, Vestfold Hospital Trust, and Norwegian National Centre for Ageing and Health.

TRANSLATION

For the Norwegian translation of the abstract see Supplementary Materials section.

The effect of all-cause hospitalization on cognitive decline in older adults: a longitudinal study using databases of the National Health Insurance Service and the memory clinics of a self-run hospital

BACKGROUND

Cognitive decline is common in older adults and imposes a burden on public health. Especially for older adults, hospitalization can be related to decreased physical fitness. This study aimed to investigate the quantitative association between hospitalization and cognitive decline.

METHODS

This was a retrospective cohort study. We performed a longitudinal study by using the combined database from the Korean National Health Insurance Service (NHIS) and memory clinic data of its self-run hospital. We identified whether hospitalized, the number of hospitalizations, and the total hospitalization days through the claim information from the NHIS database. We also identified whether hospitalization was accompanied by delirium or surgery with general anesthesia for subgroup analysis. Primary outcome was the clinical dementia rating-sum of boxes (CDR-SB) score. Secondary outcomes were mini-mental state examination (MMSE) score, clinical dementia rating (CDR) grade, and Korean-instrumental activities of daily living (KIADL) score. Multivariable mixed models were established.

RESULTS

Of the 1810 participants, 1200 experienced hospitalization at least once during the observation period. The increase in CDR-SB was significantly greater in the hospitalized group (β = 1.5083, P < .001). The same results were seen in the total number of hospitalizations (β = 0.0208, P < .001) or the total hospitalization days (β = 0.0022, P < .001) increased. In the group that experienced hospitalization, cognitive decline was also significant in terms of CDR grade (β = 0.1773, P < .001), MMSE score (β = - 1.2327, P < .001), and KIADL score (β = 0.2983, P < .001). Although delirium (β = 0.2983, P < .001) and nonsurgical hospitalization (β = 0.2983, P < .001) were associated with faster cognitive decline, hospitalization without delirium and with surgery were also related to faster cognitive decline than in the no hospitalization group.

CONCLUSION

Cognitive decline was quantitatively related to all-cause hospitalization in older adults. Moreover, hospitalizations without delirium and surgery were also related to cognitive decline. It is vital to prevent various conditions that need hospitalization to avoid and manage cognitive dysfunction.

Three key areas in progressing delirium practice and knowledge: recognition and relief of distress, new directions in delirium epidemiology and developing better research assessments

Delirium presents formidable challenges: it affects one in four of older hospitalised adults, greatly elevates the risk of multiple short- and long-term complications including dementia and causes significant distress. Delirium care remains generally poor. Yet, there are clear grounds for optimism; the last decade has seen impactful policy advances and a tripling of research output. Here, we highlight three linked areas which have strong potential to transform delirium practice and knowledge in the near term. Delirium-related distress is strikingly underrepresented in practice guidance and research. Proactive recognition combined with effective clinical responses based on good communication provides a critical and largely untapped opportunity to improve care. Delirium epidemiology research is well positioned to produce novel insights through advanced prospective designs in populations such as emergency medical patients with detailed pre-, intra- and post-delirium assessments allied with fluid, imaging and other biomarkers. Research-grade assessment of delirium currently involves a chaotic array of tools, methods and diagnostic algorithms. Areas for development: expand and analytically distinguish the range of features assessed (including distress), optimise feature assessment including use of validated neuropsychological tests where possible, produce standardised algorithms which articulate explicit pathways from features to diagnosis, and create new fine-grained approaches to the measurement of severity. Delirium practice and knowledge show accelerating growth. This is encouraging but much of the necessary progress is still to come. Innovation in these three highlighted areas, as well as many others, will open up exciting possibilities in enhancing the care of patients with this common and often devastating condition.

Delirium can be safely managed in the community through implementation of a community toolkit: a proof-of-concept pilot study

Delirium is an acute confusional state due to physical illness and is a frequent cause of hospital admission. In this article, we describe the development and outcomes for a community delirium toolkit pilot across Greater Manchester during the COVID-19 pandemic. We conclude that delirium can be safely managed in the community by using a toolkit that incorporates structured assessment and management. Carers and patients benefited from the use of a co-designed information leaflet.