Risk Factors for Delirium in Older Medical Inpatients in Tanzania

Sex Differences in Delirium after Coronary Artery Bypass Graft Surgery and Perioperative Neuropsychiatric Conditions: A Secondary Analysis of a Cohort Study

BACKGROUND

Biological sex influences the risk of depression and cognitive impairment, but its role in relation to postoperative delirium is unclear. This analysis investigates sex differences in delirium risk after coronary artery bypass graft (CABG) surgery and sex-related differences in relation to affective and cognitive symptoms.

METHODS

This is a secondary analysis of the Neuropsychiatric Outcomes After Heart Surgery (NOAHS) study, a single-site, observational study of a CABG surgery cohort (n = 149). Preoperative characteristics are stratified by sex, and baseline variables that differ by sex are evaluated to understand whether sex modifies their relationships with delirium. We also evaluate sex differences in one-month depression and cognition.

RESULTS

Female sex is associated with several delirium risk factors, including higher risk of preoperative depression and middle cerebral artery (MCA) stenosis. MCA stenosis was statistically associated with delirium only among women (OR 15.6, 95% CI 1.5, 164.4); mild cognitive impairment (MCI) was associated with delirium only in men (OR 4.6, 95% CI 1.2, 17.9). Other sex-based differences failed to reach statistical significance. Depression remained commoner among women 1 month post-CABG.

CONCLUSIONS

Women in this CABG cohort were more likely to have depression at baseline and 1 month postoperatively, as well as MCA stenosis and postoperative delirium. Sex might modify the relationship between post-CABG delirium and its risk factors including MCA stenosis and MCI. Cerebrovascular disease deserves study as a potential explanation linking female sex and a range of poor outcomes among women with coronary heart disease.

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.

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.

Dementia in Africa: Current evidence, knowledge gaps, and future directions

In tandem with the ever-increasing aging population in low and middle-income countries, the burden of dementia is rising on the African continent. Dementia prevalence varies from 2.3% to 20.0% and incidence rates are 13.3 per 1000 person-years with increasing mortality in parts of rapidly transforming Africa. Differences in nutrition, cardiovascular factors, comorbidities, infections, mortality, and detection likely contribute to lower incidence. Alzheimer's disease, vascular dementia, and human immunodeficiency virus/acquired immunodeficiency syndrome-associated neurocognitive disorders are the most common dementia subtypes. Comprehensive longitudinal studies with robust methodology and regional coverage would provide more reliable information. The apolipoprotein E (APOE) ε4 allele is most studied but has shown differential effects within African ancestry compared to Caucasian. More candidate gene and genome-wide association studies are needed to relate to dementia phenotypes. Validated culture-sensitive cognitive tools not influenced by education and language differences are critically needed for implementation across multidisciplinary groupings such as the proposed African Dementia Consortium.

Prevalence, Risk Factors, and Impact of Delirium on Hospitalized Older Adults With Dementia: A Systematic Review and Meta-Analysis

OBJECTIVES

High prevalence of delirium superimposed on dementia (DSD) was previously reported, with associated negative impact on hospitalized older adults. However, data were conflicting, and no meta-analysis has been conducted. Although dementia is the leading risk factor for delirium, risk factors for DSD have not been adequately studied. This systematic review and meta-analysis aims to elucidate the prevalence, risk factors, and impact of DSD in hospitalized older adults. Comparisons were made between older adults with DSD and persons with dementia alone (PWDs).

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

Observational studies reporting prevalence, risk factors, or impact of DSD in hospitalized older adults.

METHODS

Database search was conducted till December 2020 in PubMed, Embase, CENTRAL, PsycINFO, CINAHL, Scopus, Web of Science, ProQuest, and OpenGrey for relevant primary and secondary studies. A piloted data collection form was used for data extraction, and methodological quality was assessed using Joanna Briggs Institute critical appraisal checklists. Meta-analyses, with risk ratio and mean differences as effect measures, were performed using random effects model with Review Manager software. Cochran's Q and I² statistics were used to assess heterogeneity, which was investigated using subgroup analyses.

RESULTS

A total of 81 studies were eligible. The pooled prevalence of DSD was 48.9%, with the highest prevalence found in the Americas and orthopedic wards. Risk factors, including nonmodifiable hospital-, illness-, and medication-related factors, were found to precipitate DSD. Patients with DSD had longer length of hospitalization, disclosed worse cognitive and functional outcomes, and a higher risk of institutionalization and mortality than patients with dementia.

CONCLUSIONS AND IMPLICATIONS

These findings suggested high prevalence and detrimental impact of DSD in hospitalized older adults, highlighting a need for early identification, prevention, and treatments. Further research on risk factors of DSD should be conducted as data were sparse and conflicting. Future high-quality studies regarding DSD are warranted to improve knowledge of this common but under-recognized phenomenon.

Risk factors for delirium among hospitalized patients in Zambia

Objective

To identify risk factors for delirium among hospitalized patients in Zambia.

Methods

We conducted a prospective cohort study at the University Teaching Hospital in Lusaka, Zambia, from October 2017 to April 2018. We report associations of exposures including sociodemographic and clinical factors with delirium over the first three days of hospital admission, assessed using a modified Brief Confusion Assessment Method (bCAM).

Findings

749 patients were included for analysis (mean age, 42.9 years; 64.8% men; 47.3% with HIV). In individual regression analyses of potential delirium risk factors adjusted for age, sex and education, factors significantly associated with delirium included being divorced/widowed (OR 1.64, 95% CI 1.09–2.47), lowest tercile income (OR 1.58, 95% CI 1.04–2.40), informal employment (OR 1.97, 95% CI 1.25–3.15), untreated HIV infection (OR 2.18, 95% CI 1.21–4.06), unknown HIV status (OR 2.90, 95% CI 1.47–6.16), history of stroke (OR 2.70, 95% CI 1.15–7.19), depression/anxiety (OR 1.52, 95% CI 1.08–2.14), alcohol overuse (OR 1.96, 95% CI 1.39–2.79), sedatives ordered on admission (OR 3.77, 95% CI 1.70–9.54), severity of illness (OR 2.00, 95% CI 1.82–2.22), neurological (OR 7.66, 95% CI 4.90–12.24) and pulmonary-system admission diagnoses (OR 1.91, 95% CI 1.29–2.85), and sepsis (OR 2.44, 95% CI 1.51–4.08). After combining significant risk factors into a multivariable regression analysis, severity of illness, history of stroke, and being divorced/widowed remained predictive of delirium (p<0.05).

Conclusion

Among hospitalized adults at a national referral hospital in Zambia, severity of illness, history of stroke, and being divorced/widowed were independently predictive of delirium. Extension of this work will inform future efforts to prevent, detect, and manage delirium in low- and middle-income countries.