Understanding the association between pain and delirium in older hospital inpatients: systematic review and meta-analysis.

OBJECTIVE: Delirium and pain are common in older adults admitted to hospital. The relationship between these is unclear, but clinically important. We aimed to systematically review the association between pain (at rest, movement, pain severity) and delirium in this population. METHODS: PubMed, EMBASE, CINAHL, PsycINFO, Cochrane and Web of Science were searched (January 1982-November 2022) for Medical Subject Heading terms and synonyms ('Pain', 'Analgesic', 'Delirium'). Study eligibility: (1) validated pain measure as exposure, (2) validated delirium tool as an outcome; participant eligibility: (1) medical or surgical (planned/unplanned) inpatients, (2) admission length ≥ 48 h and (3) median cohort age over 65 years. Study quality was assessed with the Newcastle Ottawa Scale. We collected/calculated odds ratios (ORs) for categorical data and standard mean differences (SMDs) for continuous data and conducted multi-level random-intercepts meta-regression models. This review was prospectively registered with PROSPERO [18/5/2020] (CRD42020181346). RESULTS: Thirty studies were selected: 14 reported categorical data; 16 reported continuous data. Delirium prevalence ranged from 2.2 to 55%. In the multi-level analysis, pain at rest (OR 2.14; 95% confidence interval [CI] 1.39-3.30), movement (OR 1.30; 95% CI 0.66-2.56), pain categorised as 'severe' (OR 3.42; 95% CI 2.09-5.59) and increased pain severity when measured continuously (SMD 0.33; 95% CI 0.08-0.59) were associated with an increased delirium risk. There was substantial heterogeneity in both categorical (I2 = 0%-77%) and continuous analyses (I2 = 85%). CONCLUSION: An increase in pain was associated with a higher risk of developing delirium. Adequate pain management with appropriate analgesia may reduce incidence and severity of delirium.

Validity and reliability of the Turkish version of the Informant Assessment of Geriatric Delirium Scale.

Background and purpose:

Delirium is a common complication developing in el­der­ly patients. Therefore, it is important to diagnose delirium earlier. Family caregivers play an active role in early diagnosis of de­lirium and build a bridge between health pro­fessionals and patients. The purpose of this research was to achieve the validity and reliability of the Turkish version of the Informant Assessment of Geriatric Delirium Scale (I-AGeD).

This is a methodological study. The sample comprised 125 caregivers ac­cepting to participate in the study and offering care to older patients with hip fracture aged ≥60 years. Data were gathered preoperatively and on postoperative days 0, 1 and 2. After achieving the linguistic and content validity of the scale, the known-groups comparison was used to achieve its construct validity. The ROC curve analysis was made to determine the sensitivity and specificity of the scale. Item-total correlations, item analysis based on the difference between the upper 27% and lower 27%, Kuder–Richardson 20 (KR-20) coefficient and parallel forms reliability with the NEECHAM Confusion Scale were adapted to assess discriminant indices of the items in the I-AGeD.

The item-total correlation coeffi­cients of the scale ranged from 0.54 to 0.89 and KR-20 coefficient ranged from 0.09 to 0.91 depending on the measurement times. According to the ROC curve analysis, the sensitivity and specificity of the scale were ≥ 91% and ≥ 96% respectively. The parallel forms reliability analysis showed a highly significant, strong negative relation at each measurement between the I-AGeD and the NEECHAM Confusion Scale. 

The I-AGeD is valid and reliable to diagnose delirium in older Turkish patients in perioperative processes.

Delirium screening in the emergency department: evaluation and intervention.

BACKGROUND: Between 8-17% of older adults, and up to 40% of those arriving from nursing homes, present with delirium upon admission to the Emergency Department (ED). However, this condition often remains undiagnosed by ED medical staff. We investigated the prevalence of delirium among patients aged 65 and older admitted to the ED and assessed the impact of a prospective study aimed at increasing awareness. METHODS: The study was structured into four phases: a "pre-intervention period" (T0); an "awareness period" (T1), during which information about delirium and its diagnosis was disseminated to ED staff; a "screening period" (T2), in which dedicated evaluators screened ED patients aged 65 and older; and a "post-intervention period" (T3), following the departure of the evaluators. Delirium screening was conducted using the Brief Confusion Assessment Method (bCAM) questionnaire. RESULTS: During the T0 and T1 periods, the rate of delirium diagnosed by ED staff was below 1%. The evaluators identified a delirium rate of 14.9% among the screened older adults during the T2 period, whereas the rate among those assessed by ED staff was between 1.6% and 1.9%. Following the evaluators' departure in the T3 period, the rate of delirium diagnosis decreased to 0.89%. CONCLUSIONS: This study underscores that a significant majority of older adult delirium cases remain undetected by ED staff. Despite efforts to increase awareness, the rate of diagnosis did not significantly improve. While the presence of dedicated delirium evaluators slightly increased the diagnosis rate among patients assessed by ED staff, this rate reverted to pre-intervention levels after the evaluators left. These findings emphasize the necessity of implementing mandatory delirium screening during ED triage and throughout the patient's stay.

Sleep and circadian biomarkers of postoperative delirium (SLEEP-POD): protocol for a prospective and observational cohort study.

INTRODUCTION: Surgical patients over 70 experience postoperative delirium (POD) complications in up to 50% of procedures. Sleep/circadian disruption has emerged as a potential risk factor for POD in epidemiological studies. This protocol presents a single-site, prospective observational study designed to examine the relationship between sleep/circadian regulation and POD and how this association could be moderated or mediated by Alzheimer's disease (AD) pathology and genetic risk for AD. METHODS AND ANALYSIS: Study staff members will screen for eligible patients (age ≥70) seeking joint replacement or spinal surgery at Massachusetts General Hospital (MGH). At the inclusion visit, patients will be asked a series of questionnaires related to sleep and cognition, conduct a four-lead ECG recording and be fitted for an actigraphy watch to wear for 7 days before surgery. Blood samples will be collected preoperatively and postoperatively and will be used to gather information about AD variant genes (APOE-ε4) and AD-related pathology (total and phosphorylated tau). Confusion Assessment Method-Scale and Montreal Cognitive Assessment will be completed twice daily for 3 days after surgery. Seven-day actigraphy assessments and Patient-Reported Outcomes Measurement Information System questionnaires will be performed 1, 3 and 12 months after surgery. Relevant patient clinical data will be monitored and recorded throughout the study. ETHICS AND DISSEMINATION: This study is approved by the IRB at MGH, Boston, and it is registered with the US National Institutes of Health on ClinicalTrials.gov (NCT06052397). Plans for dissemination include conference presentations at a variety of scientific institutions. Results from this study are intended to be published in peer-reviewed journals. Relevant updates will be made available on ClinicalTrials.gov. TRIAL REGISTRATION NUMBER: NCT06052397.

Assessment and report of individual symptoms in studies of delirium in postoperative populations: a systematic review.

OBJECTIVES: Delirium is most often reported as present or absent. Patients with symptoms falling short of the diagnostic criteria for delirium fall into 'no delirium' or 'control' groups. This binary classification neglects individual symptoms and may be hindering identification of the pathophysiology underlying delirium. This systematic review investigates which individual symptoms of delirium are reported by studies of postoperative delirium in adults. METHODS: Medline, EMBASE and Web of Science databases were searched on 03 June 2021 and 06 April 2023. Two reviewers independently examined titles and abstracts. Each paper was screened in duplicate and conflicting decisions settled by consensus discussion. Data were extracted, qualitatively synthesised and narratively reported. All included studies were quality assessed. RESULTS: These searches yielded 4,367 results. After title and abstract screening, 694 full-text studies were reviewed, and 62 deemed eligible for inclusion. This review details 11,377 patients including 2,049 patients with delirium. In total, 78 differently described delirium symptoms were reported. The most reported symptoms were inattention (N = 29), disorientation (N = 27), psychomotor agitation/retardation (N = 22), hallucination (N = 22) and memory impairment (N = 18). Notably, psychomotor agitation and hallucinations are not listed in the current Diagnostic and Statistical Manual for Mental Disorders-5-Text Revision delirium definition. CONCLUSIONS: The 78 symptoms reported in this systematic review cover domains of attention, awareness, disorientation and other cognitive changes. There is a lack of standardisation of terms, and many recorded symptoms are synonyms of each other. This systematic review provides a library of individual delirium symptoms, which may be used to inform future reporting.

Evaluation of Delirium Among Elders in the Emergency Department: A Cross-Sectional Study.

BACKGROUND: Health care professionals underestimate the recognition of delirium in emergency departments (EDs). In these settings, between 57% and 83% of cases of delirium go undetected. When delirium occurs, it causes an increase in the length of hospitalization, readmissions within 30 days, and mortality. No studies were carried out in Italy to assess the prevalence of delirium among elders in EDs. OBJECTIVES: The primary goal of the study was to evaluate the prevalence of the risk of delirium in people 65 years and older hospitalized in the ED for a minimum of 8 hours. The study's secondary goal was to identify the variables that influenced the risk of delirium. METHOD: A multicenter cross-sectional study was conducted in 2 EDs. The risk of delirium was assessed using the delirium screening tool 4 A's test. One hundred patients were enrolled. Data collection took place from June 28 to August 31, 2022. RESULTS: The risk of delirium was detected in 29% of the sample, whereas the risk of cognitive impairment was 13%. The use of psychotropic drugs increased the risk of delirium by 11.8 times (odds ratio [OR], 11.80; P = .003). Bed confinement increased the risk by 4.3 times (OR, 4.31; P = .009). Being dehydrated increased the risk of onset by 4.6 times (OR, 4.62; P = .010). Having dementia increased the risk of delirium manifestation by 4.4 times (OR, 4.35; P = .021). DISCUSSION: The risk of delirium was detected in a considerable portion of the sample. The results of this study can be used by health care professionals to implement preventive measures as well as support clinical judgment and establish priorities of care for patients at risk of developing delirium.

Metabolomic Analysis in Saliva and Different Brain Regions of Older Mice with Postoperative Delirium Behaviors.

Objective: Postoperative delirium (POD) has become a critical challenge with severe consequences and increased incidences as the global population ages. However, the underlying mechanism is yet unknown. Our study aimed to explore the changes in metabolites in three specific brain regions and saliva of older mice with postoperative delirium behavior and to identify potential non-invasive biomarkers. Methods: Eighteen-month-old male C57/BL6 mice were randomly assigned to the anesthesia/surgery or control group. Behavioral tests were conducted 24 h before surgery and 6, 9, and 24 h after surgery. Complement C3 (C3) and S100 calcium-binding protein B protein (S100beta) levels were measured in the hippocampus, and a metabolomics analysis was performed on saliva, hippocampus, cortex, and amygdala samples. Results: In total, 43, 33, 38, and 14 differential metabolites were detected in the saliva, hippocampus, cortex, and amygdala, respectively. "Pyruvate" "alpha-linolenic acid" and "2-oleoyl-1-palmitoy-sn-glycero-3-phosphocholine" are enriched in one common pathway and may be potential non-invasive biomarkers for POD. Common changes were observed in the three brain regions, with the upregulation of 1-methylhistidine and downregulation of D-glutamine. Conclusion: Dysfunctions in energy metabolism, oxidative stress, and neurotransmitter dysregulation are implicated in the development of POD. The identification of changes in the level of salivary metabolite biomarkers could aid in the development of noninvasive diagnostic methods for POD.

Scoring systems, expert assessment, and identification of risk factors for the emergence of delirium in paediatric patients: Prospective cohort study.

INTRODUCTION: Emergence delirium (ED) is a transient irritative and dissociative state that arises after the cessation of anaesthesia in patients who do not respond to calming measures. There are many risk factors for ED, but the exact cause and underlying mechanism have not been determined because the definition of ED is still unclear in consensus. This study aims to determine ED incidence, identify ED risk factors and external validation of Watcha, Cravero and expert assessment to Pediatric Anesthesia Emergence Delirium (PAED) scoring system in ED prediction. MATERIALS AND METHODS: This study is a prospective cohort study on 79 paediatrics who underwent elective surgery with general anaesthesia. Parameter measures include the incidence of ED, ED risk factors, and the relationship between PAED, Watcha, Cravero score and expert assessment. The ED risk factor was analysed using univariate and multivariate analysis. The relationship between PAED, Watcha, Cravero score, and expert assessment was determined using Receiver Operating Characteristic (ROC) curve analysis. RESULTS: The incidence of ED was 22.8%. All parameters examined in this study showed p < 0.05. Watcha's scoring correlates with the PAED scoring and shows the highest discrimination ability with AUC 0.741 and p < 0.05. CONCLUSION: The incidence of ED in paediatrics is relatively high. Compared to others, Watcha score are more reliable for ED prediction. However, some demographic and perioperative factors are not the risk factor of ED.

Delirium screening instruments.

Delirium in patients has well-documented adverse physical and mental outcomes. Delirium impairs patients' capacity to grasp and retain information, thus affecting their right to informed consent and active participation in treatment and care decisions. In Danish hospitals, delirium afflicts up to 50% of the elderly patients, yet it often goes unreported due to the absence of systematic screening. The selection of a screening tool should be contextually relevant. This review gives an overview of delirium screening instruments available in Danish, each with distinct advantages and disadvantages.

The evaluation of frequency and predictors of delirium and its short-term and long-term outcomes in hospitalized older adults'.

BACKGROUND: Delirium is a common complication in hospitalized older adults with multifactorial etiology and poor health outcomes. AIM: To determine the frequency and predictors of delirium and its short-term and long-term outcomes in hospitalized older adults. METHODS: A prospective observational study was performed in patients aged ≥60 years consecutively admitted to geriatric ward. Potential risk factors were assessed within 24 hours of hospital admission. Delirium screening was performed on admission and daily thereafter throughout the hospital stay using Confusion Assessment Method (CAM). Patients were followed up at 1-year post-discharge. RESULTS: The study included 200 patients with mean age 73.1 ± 8.83 years. Incidence and prevalence rate of delirium were 5% and 20% respectively. Multivariable regression analysis revealed emergency admission (OR= 5.12 (1.94-13.57), p=0.001), functional dependency (Katz index of Independence in Activities of Daily Living (Katz-ADL) score <5) 2 weeks before admission (OR= 3.08 (1.30-7.33), p=0.011) and more psychopathological symptoms (higher Brief Psychiatric Rating Scale (BPRS) total score) (OR=1.12 (1.06-1.18), p=0.001) to be independently associated with delirium. Patients in delirium group had significantly high in-hospital mortality (OR= 5.02 (2.12-11.8), p=0.001) and post-discharge mortality (HR= 2.02 (1.13-3.61), p=0.017) and functional dependency (Katz-ADL score <5) (OR= 5.45 (1.49-19.31), p=0.01) at 1-year follow up. CONCLUSION: Delirium is quite frequent in geriatric inpatients and is associated with high in-hospital and post-discharge mortality risk and long-term functional dependency. Emergency admission, pre-hospitalization functional dependency, and more general psychopathological symptoms are independently associated factors. Hence, earliest identification and treatment with early implementation of rehabilitation services is warranted.

An exploratory study on the heterogeneity of postoperative delirium: Preoperative cognitive screening does not detect hallucinatory delirium risk.

INTRODUCTION: This study compared the clinical characteristics of patients who had hallucinations and those who did not during delirium after elective cancer surgery. MATERIALS AND METHODS: This study retrospectively observed 1137 consecutive patients who had preoperative screening by a trained nurse before elective major urologic cancer surgery in our department. We compared the patient characteristics, including mini-cognitive assessment instrument (Mini-Cog) and Geriatric-8 (G8) scores, between those who developed postoperative delirium and those who did not, and also between those who had hallucinations and those who did not during delirium. RESULTS: Out of 1137 patients, 68 developed postoperative delirium, and 12 of them had hallucinations. A hierarchical cluster analysis based on the G8 and Mini-Cog scores divided the patients into two groups: one with high G8 and cognitive function (36 patients) and one with low G8 and cognitive function (32 patients). Hallucinations during delirium were more frequent in the high G8 and cognitive function group (11 out of 36 patients) than in the low G8 and cognitive function group (one out of 32 patients). Patients who had hallucinations during delirium also had higher preoperative Mini-Cog scores (P = 0.002) and G8 scores (P = 0.03) than those who did not, indicating better cognitive function and less frailty. DISCUSSIONS: We identified a patient population that is prone to hallucinations that preoperative screening tools cannot detect. This suggests the heterogeneity of postoperative delirium and the need for further research.

Validation of a viable delirium detection test performed by nurses and physicians during routine patient care.

BACKGROUND: Delirium is a frequent mental impairment in geriatric patients hospitalized in acute care facilities. It carries a high risk of complications and is often the first symptom of acute illness. It is clearly important to identify the development of delirium at an early stage, and several short and effective diagnostic tests have been developed and validated for this purpose. Despite this, patients on hospital wards are seldom monitored for signs of emergent delirium, suggesting that compliance with guidelines would be improved by introducing a simpler and more user-friendly test. METHODS: We recently implemented a simple delirium assessment tool, called RMA that can be introduced into the daily routine of ward staff without significantly adding to their workload. The nurses noted their impression of the patient's cognitive state in the electronic medical record, and during the morning round the ward physician administered a short attention test to any patients suspected of new cognitive impairment. In this study, we compared RMA test against the widely used and well validated 4AT. RESULTS: RMA performed daily by the ward staff was found to be non-inferior to 4AT performed by an experienced rater. Compared to 4AT, R&M had a sensitivity of 93.9% and a specificity of 98.3%. An Altman-Bland plot indicated that both tests can be used interchangeably. CONCLUSIONS: The RMA test is reliable, easy to administer, likely to boost compliance with guidelines, and is expected to raise awareness of delirium among the nurses and physicians directly involved in the diagnostic process.

Nursing Care of a Child With Delirium Receiving Venoarterial Extracorporeal Membrane Oxygenation: A Case Report.

INTRODUCTION: Children receiving extracorporeal membrane oxygenation are prone to delirium. This case report describes the nursing care of a child with delirium who received venoarterial extracorporeal membrane oxygenation. Relevant interventions and precautions are also discussed. CLINICAL FINDINGS: A 6-year-old girl was admitted to the pediatric intensive care unit with a 2-day history of vomiting and fever. The child underwent cannulation for venoarterial extracorporeal membrane oxygenation. DIAGNOSIS: The child was diagnosed with acute fulminant myocarditis, cardiac shock, and ventricular arrhythmia. INTERVENTIONS: On the third day of extracorporeal membrane oxygenation, bedside nurses began using the Cornell Assessment of Pediatric Delirium to assess the child for delirium symptoms. The team of physicians and nurses incorporated a nonpharmacologic delirium management bundle into pediatric daily care. Delirium screening, analgesia and sedation management, sleep promotion, and family participation were implemented. OUTCOMES: During the 18 days of pediatric intensive care unit hospitalization, the child had 6 days of delirium: 1.5 days of hypoactive delirium, 1.5 days of hyperactive delirium, and 3 days of mixed delirium. The child was successfully discharged home on hospital day 22. CONCLUSION: Caring for a child with delirium receiving venoarterial extracorporeal membrane oxygenation required multidimensional nursing capabilities to prevent and reduce delirium while ensuring safe extracorporeal membrane oxygenation. This report may assist critical care nurses caring for children under similar circumstances.

Risk factors for hypoactive delirium in patients with nontraumatic ARDS: a prospective observational study.

To investigate the incidence, characteristics and risk factors for hypoactive delirium in patients with nontraumatic acute respiratory distress syndrome (ARDS) and to explore the independent risk factors associated with hypoactive delirium and provide new ideas for early prediction and treatment. Hypoactive delirium is a known serious complication in ARDS patients, and currently, there are no effective early detection models or clinical prediction tools, and there is a lack of clinical treatment. This study included nontraumatic ARDS patients who stayed in the intensive care unit (ICU) for more than 24 h and were older than 18 years. A total of 205 ARDS patients admitted to the ICU of Gansu Provincial People's Hospital between December 2021 and February 2023 were selected. Demographic data, clinical characteristics and laboratory test results were collected within 24 h after the patients entered the ICU. Multivariate logistic regression analysis was used to investigate risk factors, evaluate the clinical prediction effect of the model and construct a nomogram for visual display. The incidence of hypoactive delirium among the patients included in the study was 41%. Patients with hypoactive delirium had hypertension; diabetes mellitus; Acute Physiology and Chronic Health Evaluation II (APACHE II) scores ≥ 15; and increased procalcitonin, C-reactive protein (CRP), lactic dehydrogenase and interleukin-6 (IL-6) levels compared with those without hypoactive delirium. Logistic regression analysis revealed that diabetes mellitus (OR 3.305, 95% CI: 1.866-12.616; p = 0.047), CRP level (OR 1.002, 95% CI: 1.001-1.023; p = 0.044), and IL-6 level (OR 1.045, 95% CI: 1.017-1.063; p = 0.001) were independent risk factors for hypoactive delirium. After receiver operating characteristic (ROC) curve analysis, calibration plot and decision curve analysis (DCA) confirmed that the clinical prediction ability of this study model was satisfactory, and a nomogram was drawn for visual display. Hypoactive delirium is a common serious complication in nontraumatic ARDS patients. Our logistic regression model not only effectively predicts hypoactive delirium early but also reveals potential clinical therapeutic targets.

How to manage catatonia, Parkinson and dementia in ICU.

PURPOSE OF REVIEW: The rising prevalence of neurodegenerative and mental disorders, combined with the challenges posed by their frailty, has presented intensivists with complex issues in the intensive care unit (ICU). This review article explores specific aspects of care for patients with catatonia, Parkinson's disease (PD), and dementia within the context of the ICU, shedding light on recent developments in these fields. RECENT FINDINGS: Catatonia, a neuropsychiatric syndrome with potentially life-threatening forms, remains underdiagnosed, and its etiologies are diverse. PD patients in the ICU present unique challenges related to admission criteria, dopaminergic treatment, and respiratory care. Dementia increases the risk of delirium. Delirium is associated with long-term cognitive impairment and dementia. SUMMARY: While evidence is lacking, further research is needed to guide treatment for ICU patients with these comorbidities.

Acute encephalopathy in the ICU: a practical approach.

PURPOSE OF REVIEW: Acute encephalopathy (AE) - which frequently develops in critically ill patients with and without primary brain injury - is defined as an acute process that evolves rapidly and leads to changes in baseline cognitive status, ranging from delirium to coma. The diagnosis, monitoring, and management of AE is challenging. Here, we discuss advances in definitions, diagnostic approaches, therapeutic options, and implications to outcomes of the clinical spectrum of AE in ICU patients without primary brain injury. RECENT FINDINGS: Understanding and definitions of delirium and coma have evolved. Delirium is a neurocognitive disorder involving impairment of attention and cognition, usually fluctuating, and developing over hours to days. Coma is a state of unresponsiveness, with absence of command following, intelligible speech, or visual pursuit, with no imaging or neurophysiological evidence of cognitive motor dissociation. The CAM-ICU(-7) and the ICDSC are validated, guideline-recommended tools for clinical delirium assessment, with identification of clinical subtypes and stratification of severity. In comatose patients, the roles of continuous EEG monitoring and neuroimaging have grown for the early detection of secondary brain injury and treatment of reversible causes. SUMMARY: Evidence-based pharmacologic treatments for delirium are limited. Dexmedetomidine is effective for mechanically ventilated patients with delirium, while haloperidol has minimal effect of delirium but may have other benefits. Specific treatments for coma in nonprimary brain injury are still lacking.

Delirium and incident dementia in hospital patients in New South Wales, Australia: retrospective cohort study.

OBJECTIVES: To determine the strength and nature of the association between delirium and incident dementia in a population of older adult patients without dementia at baseline. DESIGN: Retrospective cohort study using large scale hospital administrative data. SETTING: Public and private hospitals in New South Wales, Australia between July 2001 and March 2020. PARTICIPANTS: Data were extracted for 650 590 hospital patients aged ≥65 years. Diagnoses of dementia and delirium were identified from ICD-10 (international classification of diseases, 10th revision) codes. Patients with dementia at baseline were excluded. Delirium-no delirium pairs were identified by matching personal and clinical characteristics, and were followed for more than five years. MAIN OUTCOME MEASURES: Cox proportional hazards models and Fine-Gray hazard models were used to estimate the associations of delirium with death and incident dementia, respectively. Delirium-outcome dose-response associations were quantified, all analyses were performed in men and women separately, and sensitivity analyses were conducted. RESULTS: The study included 55 211 matched pairs (48% men, mean age 83.4 years, standard deviation 6.5 years). Collectively, 58% (n=63 929) of patients died and 17% (n=19 117) had a newly reported dementia diagnosis during 5.25 years of follow-up. Patients with delirium had 39% higher risk of death (hazard ratio 1.39, 95% confidence interval 1.37 to 1.41) and three times higher risk of incident dementia (subdistribution hazard ratio 3.00, 95% confidence interval 2.91 to 3.10) than patients without delirium. The association with dementia was stronger in men (P=0.004). Each additional episode of delirium was associated with a 20% increased risk of dementia (subdistribution hazard ratio 1.20, 95% confidence interval 1.18 to 1.23). CONCLUSIONS: The study findings suggest delirium was a strong risk factor for death and incident dementia among older adult patients. The data support a causal interpretation of the association between delirium and dementia. The clinical implications of delirium as a potentially modifiable risk factor for dementia are substantial.

Delirium is more common and associated with worse outcomes in Parkinson's disease compared to older adult controls: results of two prospective longitudinal cohort studies.

BACKGROUND: Inpatient prevalence of Parkinson's disease (PD) delirium varies widely across the literature. Delirium in general older populations is associated with adverse outcomes, such as increased mortality, dementia, and institutionalisation. However, to date there are no comprehensive prospective studies in PD delirium. This study aimed to determine delirium prevalence in hospitalised PD participants and the association with adverse outcomes, compared to a control group of older adults without PD. METHODS: Participants were hospitalised inpatients from the 'Defining Delirium and its Impact in Parkinson's Disease' and the 'Delirium and Cognitive Impact in Dementia' studies comprising 121 PD participants and 199 older adult controls. Delirium was diagnosed prospectively using the Diagnostic and Statistical Manual of Mental Disorders 5th Edition criteria. Outcomes were determined by medical note reviews and/or home visits 12 months post hospital discharge. RESULTS: Delirium was identified in 66.9% of PD participants compared to 38.7% of controls (p < 0.001). In PD participants only, delirium was associated with a significantly higher risk of mortality (HR = 3.3 (95% confidence interval [CI] = 1.3-8.6), p = 0.014) and institutionalisation (OR = 10.7 (95% CI = 2.1-54.6), p = 0.004) 12 months post-discharge, compared to older adult controls. However, delirium was associated with an increased risk of developing dementia 12 months post-discharge in both PD participants (OR = 6.1 (95% CI = 1.3-29.5), p = 0.024) and in controls (OR = 13.4 (95% CI = 2.5-72.6), p = 0.003). CONCLUSION: Delirium is common in hospitalised PD patients, affecting two thirds of patients, and is associated with increased mortality, institutionalisation, and dementia. Further research is essential to understand how to accurately identify, prevent and manage delirium in people with PD who are in hospital.