Predictors of Delirium Development in Older Medical Inpatients: Readily Identifiable Factors at Admission

Requesting That Delirium Achieve Parity With Acute Encephalopathy in the MS-DRG System

Since 2007, the Medicare Severity Diagnosis Related Groups classification system has favored billing codes for acute encephalopathy over delirium codes in determining hospital reimbursement and several quality-of-care value metrics, despite broad overlap between these sets of diagnostic codes. Toxic and metabolic encephalopathy codes are designated as major complication or comorbidity, whereas causally specified delirium codes are designated as complication or comorbidity and thus associated with a lower reimbursement and lesser impact on value metrics. The authors led a submission to the U.S. Centers for Medicare and Medicaid Services requesting that causally specified delirium be designated major complication or comorbidity alongside toxic and metabolic encephalopathy. Delirium warrants reclassification because it satisfies U.S. Centers for Medicare and Medicaid Services' guiding principles for re-evaluating Medicare Severity Diagnosis Related Group severity levels. Delirium: (1) has a bidirectional relationship with the permanent condition of dementia (major neurocognitive disorder per DSM-5-TR), (2) indexes vulnerability across populations, (3) impacts healthcare systems across levels of care, (4) complicates postoperative recovery, (5) consigns patients to higher levels of care, (6) impedes patient engagement in care, (7) has several recent treatment guidelines, (8) often indicates neuronal/brain injury, and (9) represents a common expression of terminal illness. The proposal's impact was explored using the 2019 National Inpatient Sample, which suggested that increasing delirium's complexity designation would lead to an upcoding of less than 1% of eligible discharges. Parity for delirium is essential to enhancing awareness of delirium's clinical and economic costs. Appreciating delirium's impact would encourage delirium prevention and screening efforts, thereby mitigating its dire outcomes for patients, families, and healthcare systems.

Extremes of baseline cognitive function determine the severity of delirium: a population study

Although delirium is a significant clinical and public health problem, little is understood about how specific vulnerabilities underlie the severity of its presentation. Our objective was to quantify the relationship between baseline cognition and subsequent delirium severity. We prospectively investigated a population-representative sample of 1510 individuals aged ≥70 years, of whom 209 (13.6%) were hospitalized across 371 episodes (1999 person-days assessment). Baseline cognitive function was assessed using the modified Telephone Interview for Cognitive Status, supplemented by verbal fluency measures. We estimated the relationship between baseline cognition and delirium severity [Memorial Delirium Assessment Scale (MDAS)] and abnormal arousal (Observational Scale of Level of Arousal), adjusted by age, sex, frailty and illness severity. We conducted further analyses examining presentations to specific hospital settings and common precipitating aetiologies. The median time from baseline cognitive assessment to admission was 289 days (interquartile range 130 to 47 days). In admitted patients, delirium was present on at least 1 day in 45% of admission episodes. The average number of days with delirium (consecutively positive assessments) was 3.9 days. Elective admissions accounted for 88 bed days (4.4%). In emergency (but not elective) admissions, we found a non-linear U-shaped relationship between baseline global cognition and delirium severity using restricted cubic splines. Participants with baseline cognition 2 standard deviations below average (z-score = -2) had a mean MDAS score of 14 points (95% CI 10 to 19). Similarly, those with baseline cognition z-score = + 2 had a mean MDAS score of 7.9 points (95% CI 4.9 to 11). Individuals with average baseline cognition had the lowest MDAS scores. The association between baseline cognition and abnormal arousal followed a comparable pattern. C-reactive protein ≥20 mg/l and serum sodium <125 mM/l were associated with more severe delirium. Baseline cognition is a critical determinant of the severity of delirium and associated changes in arousal. Emergency admissions with lowest and highest baseline cognition who develop delirium should receive enhanced clinical attention.

Predisposing and Precipitating Factors Associated With Delirium: A Systematic Review

IMPORTANCE

Despite discrete etiologies leading to delirium, it is treated as a common end point in hospital and in clinical trials, and delirium research may be hampered by the attempt to treat all instances of delirium similarly, leaving delirium management as an unmet need. An individualized approach based on unique patterns of delirium pathophysiology, as reflected in predisposing factors and precipitants, may be necessary, but there exists no accepted method of grouping delirium into distinct etiologic subgroups.

OBJECTIVE

To conduct a systematic review to identify potential predisposing and precipitating factors associated with delirium in adult patients agnostic to setting.

EVIDENCE REVIEW

A literature search was performed of PubMed, Embase, Web of Science, and PsycINFO from database inception to December 2021 using search Medical Subject Headings (MeSH) terms consciousness disorders, confusion, causality, and disease susceptibility, with constraints of cohort or case-control studies. Two reviewers selected studies that met the following criteria for inclusion: published in English, prospective cohort or case-control study, at least 50 participants, delirium assessment in person by a physician or trained research personnel using a reference standard, and results including a multivariable model to identify independent factors associated with delirium.

FINDINGS

A total of 315 studies were included with a mean (SD) Newcastle-Ottawa Scale score of 8.3 (0.8) out of 9. Across 101 144 patients (50 006 [50.0%] male and 49 766 [49.1%] female patients) represented (24 015 with delirium), studies reported 33 predisposing and 112 precipitating factors associated with delirium. There was a diversity of factors associated with delirium, with substantial physiological heterogeneity.

CONCLUSIONS AND RELEVANCE

In this systematic review, a comprehensive list of potential predisposing and precipitating factors associated with delirium was found across all clinical settings. These findings may be used to inform more precise study of delirium's heterogeneous pathophysiology and treatment.

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.

Feasibility and potential of a bedside mini-EEG for diagnosing delirium superimposed on dementia

OBJECTIVE

Delirium superimposed on dementia (DSD) is difficult to diagnose because symptoms of delirium might be interpreted as symptoms of dementia. To improve diagnostic accuracy, we investigated the potential of a brief point-of-care EEG measurement.

METHODS

Thirty older patients were included, all with Major Neurocognitive Disorder (i.e. dementia) according to DSM-5 criteria. EEG was registered at right prefrontal and right temporal site, with eyes either open or closed for three minutes, simultaneously with the Discomfort Scale for Dementia of Alzheimer Type. The Confusion Assessment Method for the Intensive Care Unit was administered to determine the presence of symptoms of a delirium at the time of EEG administration. Video registrations were reviewed independently by two delirium experts.

RESULTS

Higher activities of delta and theta1, and lower activities of theta2, alpha, and beta activity, were found in DSD when compared to dementia only. The ratio of delta and theta power during eyes-open conditions had the highest accuracy (AUC = 0.80 [0.63-0.94]; p <.001) to distinguish DSD from dementia alone. All subjects were on benzodiazepines and half on clozapine, thus the effects of psychotropics on EEG cannot be fully excluded.

CONCLUSIONS

A brief point-of-care EEG at two sites of the head has the potential to aid in the detection of DSD.

SIGNIFICANCE

The diagnostic accuracy of EEG in recognizing or excluding delirium in patients who already have dementia is of large potential given the lack of proper diagnostic tools.

Applicability of the interventions recommended for patients at risk or with delirium in medical and post-acute settings: a systematic review and a Nominal Group Technique study

BACKGROUND

Delirium is a common condition during hospitalisation that should be prevented and treated. Several recommendations have been established to date, whereas few studies have investigated their applicability in daily practice for medical and post-acute settings.

AIM

The aim of this research exercise was to emerge the applicability of the interventions recommended by studies in the daily care of patients at risk or with delirium cared in medical and post-acute settings.

METHODS

The study was organised in three phases. A systematic literature review according to Centre for Reviews and Dissemination was conducted (January-February 2021). Cochrane Library, Pubmed, Scopus, Cumulative Index to Nursing and Allied Health Literature, Psychological Information Database, and the Joanna Briggs Institute databases were searched. Primary and secondary studies were evaluated in their methodological quality with the Standard Quality Assessment Criteria, the Critical Appraisal Skills Programme, and the Appraisal of Guidelines for Research & Evaluation. Then, the interventions identified were assessed in their applicability using the Nominal Group Technique who ranked their judgement on a four-point Likert scale from 1 (totally inapplicable) to 4 (totally applicable). Qualitative feedbacks were also considered, and a validation of the final list was performed by the Nominal Group.

RESULTS

A total of 12 studies were included producing a list of 96 interventions categorised into four macro-areas (prevention, non-pharmacological, communication and pharmacological management). The Nominal Group identified 51 interventions (average score > 3.5) as applicable in medical and post-acute settings. Then, through a process of re-reading, and revising according to the comments provided by the Nominal Group, a list of 35 interventions out of the initial 96 were judged as applicable.

CONCLUSION

Applicability should be assessed with experts in the field to understand the involved factors. One-third of interventions have been judged as applicable in the Italian context; the nurses' expertise, the work environment features, and the time required for each intervention in a high workload setting may prevent the full applicability of the interventions recommended by the literature.

Positive scores on the 4AT delirium assessment tool at hospital admission are linked to mortality, length of stay and home time: two-centre study of 82,770 emergency admissions

BACKGROUND

Studies investigating outcomes of delirium using large-scale routine data are rare. We performed a two-centre study using the 4 'A's Test (4AT) delirium detection tool to analyse relationships between delirium and 30-day mortality, length of stay and home time (days at home in the year following admission).

METHODS

The 4AT was performed as part of usual care. Data from emergency admissions in patients ≥65 years in Lothian, UK (n = 43,946) and Salford, UK (n = 38,824) over a period of $\sim$3 years were analysed using logistic regression models adjusted for age and sex.

RESULTS

4AT completion rates were 77% in Lothian and 49% in Salford. 4AT scores indicating delirium (≥4/12) were present in 18% of patients in Lothian, and 25% of patients in Salford. Thirty-day mortality with 4AT ≥4 was 5.5-fold greater than the 4AT 0/12 group in Lothian (adjusted odds ratio (aOR) 5.53, 95% confidence interval [CI] 4.99-6.13) and 3.4-fold greater in Salford (aOR 3.39, 95% CI 2.98-3.87). Length of stay was more than double in patients with 4AT scores of 1-3/12 (indicating cognitive impairment) or ≥ 4/12 compared with 4AT 0/12. Median home time at 1 year was reduced by 112 days (Lothian) and 61 days (Salford) in the 4AT ≥4 group (P < 0.001).

CONCLUSIONS

Scores on the 4AT used at scale in practice are strongly linked with 30-day mortality, length of hospital stay and home time. The findings highlight the need for better understanding of why delirium is linked with poor outcomes and also the need to improve delirium detection and treatment.

Non-pharmacological interventions for preventing delirium in hospitalised non-ICU patients

BACKGROUND

Delirium is an acute neuropsychological disorder that is common in hospitalised patients. It can be distressing to patients and carers and it is associated with serious adverse outcomes. Treatment options for established delirium are limited and so prevention of delirium is desirable. Non-pharmacological interventions are thought to be important in delirium prevention.  OBJECTIVES: To assess the effectiveness of non-pharmacological interventions designed to prevent delirium in hospitalised patients outside intensive care units (ICU).

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP to 16 September 2020. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of single and multicomponent non-pharmacological interventions for preventing delirium in hospitalised adults cared for outside intensive care or high dependency settings. We only included non-pharmacological interventions which were designed and implemented to prevent delirium.  DATA COLLECTION AND ANALYSIS: Two review authors independently examined titles and abstracts identified by the search for eligibility and extracted data from full-text articles. Any disagreements on eligibility and inclusion were resolved by consensus. We used standard Cochrane methodological procedures. The primary outcomes were: incidence of delirium; inpatient and later mortality; and new diagnosis of dementia. We included secondary and adverse outcomes as pre-specified in the review protocol. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes and between-group mean differences for continuous outcomes. The certainty of the evidence was assessed using GRADE. A complementary exploratory analysis was undertaker using a Bayesian component network meta-analysis fixed-effect model to evaluate the comparative effectiveness of the individual components of multicomponent interventions and describe which components were most strongly associated with reducing the incidence of delirium.

MAIN RESULTS

We included 22 RCTs that recruited a total of 5718 adult participants. Fourteen trials compared a multicomponent delirium prevention intervention with usual care. Two trials compared liberal and restrictive blood transfusion thresholds. The remaining six trials each investigated a different non-pharmacological intervention. Incidence of delirium was reported in all studies.  Using the Cochrane risk of bias tool, we identified risks of bias in all included trials. All were at high risk of performance bias as participants and personnel were not blinded to the interventions. Nine trials were at high risk of detection bias due to lack of blinding of outcome assessors and three more were at unclear risk in this domain.  Pooled data showed that multi-component non-pharmacological interventions probably reduce the incidence of delirium compared to usual care (10.5% incidence in the intervention group, compared to 18.4% in the control group, risk ratio (RR) 0.57, 95% confidence interval (CI) 0.46 to 0.71, I² = 39%; 14 studies; 3693 participants; moderate-certainty evidence, downgraded due to risk of bias).  There may be little or no effect of multicomponent interventions on inpatient mortality compared to usual care (5.2% in the intervention group, compared to 4.5% in the control group, RR 1.17, 95% CI 0.79 to 1.74, I² = 15%; 10 studies; 2640 participants; low-certainty evidence downgraded due to inconsistency and imprecision).  No studies of multicomponent interventions reported data on new diagnoses of dementia.  Multicomponent interventions may result in a small reduction of around a day in the duration of a delirium episode (mean difference (MD) -0.93, 95% CI -2.01 to 0.14 days, I² = 65%; 351 participants; low-certainty evidence downgraded due to risk of bias and imprecision). The evidence is very uncertain about the effect of multicomponent interventions on delirium severity (standardised mean difference (SMD) -0.49, 95% CI -1.13 to 0.14, I²=64%; 147 participants; very low-certainty evidence downgraded due to risk of bias and serious imprecision). Multicomponent interventions may result in a reduction in hospital length of stay compared to usual care (MD -1.30 days, 95% CI -2.56 to -0.04 days, I²=91%; 3351 participants; low-certainty evidence downgraded due to risk of bias and inconsistency), but little to no difference in new care home admission at the time of hospital discharge (RR 0.77, 95% CI 0.55 to 1.07; 536 participants; low-certainty evidence downgraded due to risk of bias and imprecision). Reporting of other adverse outcomes was limited.  Our exploratory component network meta-analysis found that re-orientation (including use of familiar objects), cognitive stimulation and sleep hygiene were associated with reduced risk of incident delirium. Attention to nutrition and hydration, oxygenation, medication review, assessment of mood and bowel and bladder care were probably associated with a reduction in incident delirium but estimates included the possibility of no benefit or harm.  Reducing sensory deprivation, identification of infection, mobilisation and pain control all had summary estimates that suggested potential increases in delirium incidence, but the uncertainty in the estimates was substantial.  Evidence from two trials suggests that use of a liberal transfusion threshold over a restrictive transfusion threshold probably results in little to no difference in incident delirium (RR 0.92, 95% CI 0.62 to 1.36; I² = 9%; 294 participants; moderate-certainty evidence downgraded due to risk of bias).  Six other interventions were examined, but evidence for each was limited to single studies and we identified no evidence of delirium prevention.  AUTHORS' CONCLUSIONS: There is moderate-certainty evidence regarding the benefit of multicomponent non-pharmacological interventions for the prevention of delirium in hospitalised adults, estimated to reduce incidence by 43% compared to usual care. We found no evidence of an effect on mortality. There is emerging evidence that these interventions may reduce hospital length of stay, with a trend towards reduced delirium duration, although the effect on delirium severity remains uncertain. Further research should focus on implementation and detailed analysis of the components of the interventions to support more effective, tailored practice recommendations.

Diagnosis and Risk Factors for Delirium in Elderly Patients in the Emergency Rooms and Intensive Care Unit of the National Geriatric Hospital Emergency Department: A Cross-Sectional Observational Study

Purpose

To diagnose delirium and identify risk factors for its development in elderly patients in the emergency department (ED) and intensive care units (ICU) at the National Geriatric Hospital (Vietnam).

Patients and Methods

A cross-sectional observational study was conducted with a convenience sample of non-surgical patients admitted to ED and ICU at Hanoi National Geriatric Hospital in Vietnam. In total, 163 patients met the selection criteria and were included in the study. Screening involved using the Confusion Assessment Method (CAM) and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). The diagnosis was established according to the DSM-5 and ICD-10 codes.

Results

Delirium was found in a total of 106 (63.1%) patients. The factors significantly affecting its development were vision impairment (OR, 3.3; 95% CI, 1.5 to 7.4, P=0.003), hearing impairment (OR, 3.6; 95% CI, 1.77 to 7.36, P=0.0001), acute or chronic kidney failure (OR, 7.1; 95% CI, 2.05 to 6.39, P<0.001), respiratory disorders (OR, 2.7; 95% CI, 1.4 to 5.2, P=0.004), and malnutrition (OR, 9.17; 95% CI, 3.43–24.5, P=0.0001). The list also include the fall risk factors (OR, 12.2; 95% CI, 4.1–36.3, P=0.0001), frailty (OR, 8.35; 95% CI, 3.4–20.6, P=0.0001), activities of daily living (OR, 8.35; 95% CI, 3.4–20.6, P=0.0001), hyponatremia (OR, 2.48; 95% CI, 1.07 to 5.75, P=0.001), hypernatremia (OR, 13.1; 95% CI, 1.67 to 2.5, P=0.001), and treatment interventions. In addition, delirium was linked to the duration of ICU admission (OR, 6.53; 95% CI, 4.5–25.5, P < 0.0001).

Conclusion

The CAM/CAM-ICU diagnostic algorithm makes it possible to diagnose delirium successfully. The present study confirmed the role of several premorbid and triggering factors in the occurrence of delirium in elderly patients in ED and ICU. There is a need for further research into risk factors for delirium in elderly patients.

Non-pharmacological interventions for preventing delirium in hospitalised non-ICU patients

BACKGROUND

Delirium is an acute neuropsychological disorder that is common in hospitalised patients. It can be distressing to patients and carers and it is associated with serious adverse outcomes. Treatment options for established delirium are limited and so prevention of delirium is desirable. Non-pharmacological interventions are thought to be important in delirium prevention.  OBJECTIVES: To assess the effectiveness of non-pharmacological interventions designed to prevent delirium in hospitalised patients outside intensive care units (ICU).

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP to 16 September 2020. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of single and multicomponent non-pharmacological interventions for preventing delirium in hospitalised adults cared for outside intensive care or high dependency settings. We only included non-pharmacological interventions which were designed and implemented to prevent delirium.  DATA COLLECTION AND ANALYSIS: Two review authors independently examined titles and abstracts identified by the search for eligibility and extracted data from full-text articles. Any disagreements on eligibility and inclusion were resolved by consensus. We used standard Cochrane methodological procedures. The primary outcomes were: incidence of delirium; inpatient and later mortality; and new diagnosis of dementia. We included secondary and adverse outcomes as pre-specified in the review protocol. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes and between-group mean differences for continuous outcomes. The certainty of the evidence was assessed using GRADE. A complementary exploratory analysis was undertaker using a Bayesian component network meta-analysis fixed-effect model to evaluate the comparative effectiveness of the individual components of multicomponent interventions and describe which components were most strongly associated with reducing the incidence of delirium.

MAIN RESULTS

We included 22 RCTs that recruited a total of 5718 adult participants. Fourteen trials compared a multicomponent delirium prevention intervention with usual care. Two trials compared liberal and restrictive blood transfusion thresholds. The remaining six trials each investigated a different non-pharmacological intervention. Incidence of delirium was reported in all studies.  Using the Cochrane risk of bias tool, we identified risks of bias in all included trials. All were at high risk of performance bias as participants and personnel were not blinded to the interventions. Nine trials were at high risk of detection bias due to lack of blinding of outcome assessors and three more were at unclear risk in this domain.  Pooled data showed that multi-component non-pharmacological interventions probably reduce the incidence of delirium compared to usual care (10.5% incidence in the intervention group, compared to 18.4% in the control group, risk ratio (RR) 0.57, 95% confidence interval (CI) 0.46 to 0.71, I2 = 39%; 14 studies; 3693 participants; moderate-certainty evidence, downgraded due to risk of bias).  There may be little or no effect of multicomponent interventions on inpatient mortality compared to usual care (5.2% in the intervention group, compared to 4.5% in the control group, RR 1.17, 95% CI 0.79 to 1.74, I2 = 15%; 10 studies; 2640 participants; low-certainty evidence downgraded due to inconsistency and imprecision).  No studies of multicomponent interventions reported data on new diagnoses of dementia.  Multicomponent interventions may result in a small reduction of around a day in the duration of a delirium episode (mean difference (MD) -0.93, 95% CI -2.01 to 0.14 days, I2 = 65%; 351 participants; low-certainty evidence downgraded due to risk of bias and imprecision). The evidence is very uncertain about the effect of multicomponent interventions on delirium severity (standardised mean difference (SMD) -0.49, 95% CI -1.13 to 0.14, I2=64%; 147 participants; very low-certainty evidence downgraded due to risk of bias and serious imprecision). Multicomponent interventions may result in a reduction in hospital length of stay compared to usual care (MD -1.30 days, 95% CI -2.56 to -0.04 days, I2=91%; 3351 participants; low-certainty evidence downgraded due to risk of bias and inconsistency), but little to no difference in new care home admission at the time of hospital discharge (RR 0.77, 95% CI 0.55 to 1.07; 536 participants; low-certainty evidence downgraded due to risk of bias and imprecision). Reporting of other adverse outcomes was limited.  Our exploratory component network meta-analysis found that re-orientation (including use of familiar objects), cognitive stimulation and sleep hygiene were associated with reduced risk of incident delirium. Attention to nutrition and hydration, oxygenation, medication review, assessment of mood and bowel and bladder care were probably associated with a reduction in incident delirium but estimates included the possibility of no benefit or harm.  Reducing sensory deprivation, identification of infection, mobilisation and pain control all had summary estimates that suggested potential increases in delirium incidence, but the uncertainty in the estimates was substantial.  Evidence from two trials suggests that use of a liberal transfusion threshold over a restrictive transfusion threshold probably results in little to no difference in incident delirium (RR 0.92, 95% CI 0.62 to 1.36; I2 = 9%; 294 participants; moderate-certainty evidence downgraded due to risk of bias).  Six other interventions were examined, but evidence for each was limited to single studies and we identified no evidence of delirium prevention.  AUTHORS' CONCLUSIONS: There is moderate-certainty evidence regarding the benefit of multicomponent non-pharmacological interventions for the prevention of delirium in hospitalised adults, estimated to reduce incidence by 43% compared to usual care. We found no evidence of an effect on mortality. There is emerging evidence that these interventions may reduce hospital length of stay, with a trend towards reduced delirium duration, although the effect on delirium severity remains uncertain. Further research should focus on implementation and detailed analysis of the components of the interventions to support more effective, tailored practice recommendations.

The prevalence rates and adversities of delirium: Too common and disadvantageous

Objective

The prevalence rates and adversities of delirium have not yet been systematically evaluated and are based on selected populations, limited sample sizes, and pooled studies. Therefore, this study assesses the prevalence rates and outcome of and odds ratios for managing services for delirium.

Methods

In this prospective cohort study, based on the Diagnostic and Statistical Manual (DSM) 5, the Delirium Observation Screening (DOS) scale, and the Intensive Care Delirium Screening Checklist (ICDSC) construct, 28,118 patients from 35 managing services were included, and the prevalence rates and adverse outcomes were determined by simple logistic regressions and their corresponding odds ratios (ORs).

Results

Delirious patients were older, admitted from institutions (OR 3.44–5.2), admitted as emergencies (OR 1.87), hospitalized twice longer, and discharged, transferred to institutions (OR 5.47–6.6) rather than home (OR 0.1), or deceased (OR 43.88). The rate of undiagnosed delirium was 84.2%. The highest prevalence rates were recorded in the intensive care units (47.1–84.2%, pooled 67.9%); in the majority of medical services, rates ranged from 20% to 40% (pooled 26.2%), except, at both ends, palliative care (55.9%), endocrinology (8%), and rheumatology (4.4%). Conversely, in surgery and its related services, prevalence rates were lower (pooled 13.1%), except for cardio- and neurosurgical services (53.3% and 46.4%); the lowest prevalence rate was recorded in obstetrics (2%).

Significance of results

Delirium remains underdiagnosed, and novel screening approaches are required. Furthermore, this study identified the impact of delirium on patients, determined the prevalence rates for 32 services, and elucidated the association between individual services and delirium.