Five short screening tests in the detection of prevalent delirium: diagnostic accuracy and performance in different neurocognitive subgroups

The phenotype of delirium based on a close reading of diagnostic criteria

OBJECTIVE

Although delirium is well known to acute care clinicians, the features required for its diagnosis and how to understand and operationalize them remain sticking points in the field. To clarify the delirium phenotype, we present a close reading of past and current sets of delirium diagnostic criteria.

METHODS

We first differentiate the delirium syndrome (i.e., features evaluated at bedside) from additional criteria required for diagnosis. Next, we align related features across diagnostic systems and examine them in context to determine intent. Where criteria are ambiguous, we review common delirium instruments to illustrate how they have been interpreted.

RESULTS

An acute disturbance in attention is universally attested across diagnostic systems. A second core feature denotes confusion and has been included across systems as disturbance in awareness, impaired consciousness, and thought disorganization. This feature may be better understood as a disturbance in thought clarity and operationalized in terms of neuropsychological domains thereby clearly linking it to global neurocognitive disturbance. Altered level of activity describes a third core feature, including motor and sleep/wake cycle disturbances. Excluding stupor (wherein mental content cannot be assessed due to reduced arousal) from delirium, as in DSM-5-TR, is appropriate for a psychiatric diagnosis, but the brain injury exclusion in ICD-11 is unjustified.

CONCLUSIONS

The delirium phenotype involves a disturbance in attention, qualitative thought clarity, and quantitative activity level, including in relation to expected sleep/wake cycles. Future diagnostic systems should include a severity threshold and specify that delirium diagnosis refers to a 24-h period.

The Association of Preoperative Trail Making Tests With Postoperative Delirium

Aims The aim of the present study was to investigate the preoperative Trail Making Test (TMT) and its association with postoperative delirium. Materials and methods This cross-sectional, observational study consisted of 51 patients admitted to the surgical ward for any planned operative procedure. Consenting patients provided their sociodemographic information, and the Hospital Anxiety and Depression Scale (HADS), Montreal Cognitive Assessment (MoCA) test, and Trail Making Test (TMT) were applied. Results A total of 51 patients (66.7% male and 33.3% female) were categorized as the "normal" group (n=34), completing TMT in time, and the "slow" group (n=17). The mean age was 45.05 ± 13.69 for the normal group and 44.29 ± 10.95 for the slow group. The HADS score mean was 15.02 ± 9.52 and 11.64 ± 5.73, respectively, for these two groups (t = -1.577; degrees of freedom {df} = 47.11; p = 0.121). However, the "normal" group scored significantly higher MoCA scores in comparison to the slow group (26.35 ± 1.06 and 24.29 ± 1.10, respectively) (t = -6.410; df = 49; p = 0.000). Conclusions The study shows that the TMT can indicate effectively the cognitive decline in preoperative patients, which predicts postoperative delirium.

Six-item cognitive impairment test (6-CIT)'s accuracy as a cognitive screening tool: best cut-off levels in emergency department setting

Background

Nowadays, elderly patients represent a significant number of accesses to the Emergency Department (ED). Working rhythms do not allow to perform complete cognitive analysis, which would, however, be useful for the health care. This study aims to define the optimal cut-off values of the six-item Cognitive Impairment Test (6-CIT) as a cognitive screening tool in ED.

Methods

This study included 215 subjects, evaluated at the Emergency Department of the University Hospital of Monserrato, Cagliari, Italy, from July to December 2021. The accuracy of 6-CIT as a cognitive screening tool was assessed by comparison with Mini Mental State Examination (MMSE).

Results

The correlation coefficient between the two tests was -0.836 (CI: -0.87 to -0.79; p < 0.0001), and 6-CIT showed AUC = 0.947 (CI: 0.908-0.973; p < 0.0001). The 8/9 6-CIT cut-off score presented 86.76% sensitivity (CI: 76.4-93.8) and 91.84% specificity (CI: 86.2-95.7), and Youden index for this score was 0.786.

Conclusion

Our study demonstrates that 6-CIT is a reliable cognitive screening tool in ED, offering excellent sensitivity and specificity with a 8/9 points cut-off score.

Detecting delirium: a systematic review of ultrabrief identification instruments for hospital patients

Objective

Early identification of delirium, which often occurs in older patients, can effectively reduce adverse prognoses. One way to increase the detection rate of delirium is to use an effective ultrabrief instrument for higher-frequency screening. The purpose of this review is to evaluate the diagnostic accuracy of ultrabrief screening tools for delirium.

Methods

The Cochrane Library, PubMed and EMBASE were searched from January 1, 1974, to November 31, 2022. We assessed the measurement properties of screening instruments using the consensus-based standards for selecting health measurement instruments (COSMIN) checklist and evaluated the risk bias of the included studies using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. The diagnostic test accuracy of instruments for delirium was reported using sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR).

Result

Of the 4,914 items identified, 26 met the eligibility criteria, resulting in 5 different delirium identification tools. The overall study quality assessed by the QUADAS-2 tool was moderate to good. Of the five screening tools, two instruments had sensitivity ≥80% and specificities ≥80%: 4AT and UB-2. The most comprehensive is the 4AT scale, which has a sensitivity of 0.80 [95% confidence interval (CI):0.68, 0.88] and a specificity of 0.89 (95%CI: 0.83, 0.93) and contains 4 items. UB-2 has a sensitivity of 0.88 (95%CI: 0.72, 0.96) and a specificity of 0.64 (95%CI: 0.56, 0.70).

Conclusion

UB-2 and MOTYB had excellent sensitivity for delirium screening at an early stage. In terms of sensitivity and intentionality, the 4AT is the best recommended scale.

Identifying Delirium in Persons With Moderate or Severe Dementia: Review of Challenges and an Illustrative Approach

Delirium and dementia are common causes of cognitive impairment among older adults, which often coexist. Delirium is associated with poor clinical outcomes, and is more frequent and more severe in patients with dementia. Identifying delirium in the presence of dementia, also described as delirium superimposed on dementia (DSD), is particularly challenging, as symptoms of delirium such as inattention, cognitive dysfunction, and altered level of consciousness, are also features of dementia. Because DSD is associated with poorer clinical outcomes than dementia alone, detecting delirium is important for reducing morbidity and mortality in this population. We review a number of delirium screening instruments that have shown promise for use in DSD, including the 4-DSD, combined Six Item Cognitive Impairment Test (6-CIT) and 4 'A's Test (4AT), Confusion Assessment Method (CAM), and the combined UB2 and 3D-CAM (UB-CAM). Each has advantages and disadvantages. We then describe the operationalization of a CAM-based approach in a current ECT in dementia project as an example of modifying an existing instrument for patients with moderate to severe dementia. Ultimately, any instrument modified will need to be validated against a standard clinical reference, in order to fully establish its sensitivity and specificity in the moderate to severe dementia population. Future work is greatly needed to advance the challenging area of accurate identification of delirium in moderate or severe dementia.

A systematic review and meta-analysis of the accuracy of the clock drawing test (CDT) in the identification of delirium in older hospitalised patients

Objective: Delirium is a common neurocognitive syndrome among hospitalised older adults. The clock drawing test (CDT) is a relatively simple bedside test of cognitive function. This systematic review and meta-analysis examine the accuracy of the CDT in identifying delirium in hospitalised older adults.Methods: PRISMA guidelines were used to report the identified studies. Pubmed, SCOPUS, and Ovid and EBSCO platforms (including MEDLINE ®, PsycINFO, PsycEXTRA, EMCARE, CINAHL and EMBASE databases) were searched. Studies were assessed for methodological quality using the Downs and Black Tool. Data were extracted regarding the number of delirious/not delirious, number with normal and abnormal CDT, age, and MMSE scores, and information regarding CDT scoring, criteria for diagnosis of delirium and setting of the study. Analysis was carried out with the "Mada" and "Metatron" packages of R software.Results: Fifteen studies were examined. The number of participants was 2199, of whom 597 (27.15%) were diagnosed with delirium. The overall sensitivity of CDT in the absence of any formal cognitive test was 0.76 (0.58-0.87) with specificity of 0.70 (0.51-0.83). When the MMSE was taken into account, the specificity and sensitivity reduced to 0.51. Diagnostic criteria for delirium, scoring method of CDT, age of participants and setting significantly (p < 0.05) affect the sensitivity and specificity of the CDT.Conclusion: Although, the CDT is generally considered to be a simple and easy to administer screening tool for cognitive impairment in older hospitalised adults, when a more formal cognitive test is used its sensitivity and specificity to detect delirium is low.

A novel digital clock drawing test as a screening tool for perioperative neurocognitive disorders: A feasibility study

BACKGROUND

We developed a digital clock drawing test (dCDT), an adaptation of the original pen and paper clock test, that may be advantageous over previous dCDTs in the perioperative environment. We trialed our dCDT on a tablet device in the preoperative period to determine the feasibility of administration in this setting. To assess the clinical utility of this test, we examined the relationship between the performance on the test and compared derived digital clock measures with the 4 A's Test (4AT), a delirium and cognition screening tool.

METHODS

We recruited a sample of 102 adults aged 65 years and over presenting for elective surgery in a single tertiary hospital. Participants completed the 4AT, followed by both command and copy clock conditions of the dCDT. We recorded time-based clock-drawing metrics, alongside clock replications scored using the Montreal Cognitive Assessment (MoCA) clock scoring criteria.

RESULTS

The dCDT had an acceptance rate of 99%. After controlling for demographic variables and prior tablet use, regression analyses showed higher 4AT scores were associated with greater dCDT time (seconds) for both command (β = 8.2, P = .020) and copy clocks (β = 12, P = .005) and lower MoCA-based clock scores in both command (OR = 0.19, P = .001) and copy conditions (OR = 0.14, P = .012).

CONCLUSION

The digital clock drawing test is feasible to administer and is highly acceptable to older adults in a preoperative setting. We demonstrated a significant association between both the dCDT time and clock score metrics, with the established 4AT. Our results provide convergent validity of the dCDT in the preoperative setting.

Comparison of novel tools with traditional cognitive tests in detecting delirium in elderly medical patients

BACKGROUND

Efficient detection of delirium and comorbid delirium-dementia is a key diagnostic challenge. Development of new, efficient delirium-focused methods of cognitive assessment is a key challenge for improved detection of neurocognitive disorders in everyday clinical practice.

AIM

To compare the accuracy of two novel bedside tests of attention, vigilance and visuospatial function with conventional bedside cognitive tests in identifying delirium in older hospitalized patients.

METHODS

180 consecutive elderly medical inpatients (mean age 79.6 ± 7.2; 51% female) referred to a psychiatry for later life consultation-liaison service with delirium, dementia, comorbid delirium-dementia and cognitively intact controls. Participants were assessed cross-sectionally with conventional bedside cognitive tests [WORLD, Months Backward test (MBT), Spatial span, Vigilance A and B, Clock Drawing test and Interlocking Pentagons test] and two novel cognitive tests [Lighthouse test, Letter and Shape Drawing test (LSD)-4].

RESULTS

Neurocognitive diagnoses were delirium (n = 44), dementia (n = 30), comorbid delirium-dementia (n = 60) and no neurocognitive disorder (n = 46). All conventional tests had sensitivity of > 70% for delirium, with best overall accuracy for the Vigilance-B (78.3%), Vigilance-A (77.8%) and MBT (76.7%) tests. The sustained attention component of the Lighthouse test was the most distinguishing of delirium (sensitivity 84.6%; overall accuracy 75.6%). The LSD-4 had sensitivity of 74.0% and overall accuracy 74.4% for delirium identification. Combining tests allowed for enhanced sensitivity (> 90%) and overall accuracy (≥ 75%) with the highest overall accuracy for the combination of MBT-Vigilance A and the combined Vigilance A and B tests (both 78.3%). When analyses were repeated for those with dementia, there were similar findings with the MBT-Vigilance A the most accurate overall combination (80.0%). Combining the Lighthouse-SA with the LSD-4, a fail in either test had sensitivity for delirium of 91.4 with overall accuracy of 74.4%.

CONCLUSION

Bedside tests of attention, vigilance and visuospatial ability can help to distinguish neurocognitive disorders, including delirium, from other presentations. The Lighthouse test and the LSD-4 are novel tests with high accuracy for detecting delirium.

Delirium in the intensive care setting dependent on the Richmond Agitation and Sedation Scale (RASS): Inattention and visuo-spatial impairment as potential screening domains

OBJECTIVE

In the intensive care setting, delirium is a common occurrence; however, the impact of the level of alertness has never been evaluated. Therefore, this study aimed to assess the delirium characteristics in the drowsy, as well as the alert and calm patient.

METHOD

In this prospective cohort study, 225 intensive care patients with Richmond Agitation and Sedation Scale (RASS) scores of -1 - drowsy and 0 - alert and calm were evaluated with the Delirium Rating Scale-Revised-1998 (DRS-R-98) and the Diagnostic and Statistical Manual 4th edition text revision (DSM-IV-TR)-determined diagnosis of delirium.

RESULTS

In total, 85 drowsy and 140 alert and calm patients were included. Crucial items for the correct identification of delirium were sleep-wake cycle disturbances, language abnormalities, thought process alterations, psychomotor retardation, disorientation, inattention, short- and long-term memory, as well as visuo-spatial impairment, and the temporal onset. Conversely, perceptual disturbances, delusions, affective lability, psychomotor agitation, or fluctuations were items, which identified delirium less correctly. Further, the severities of inattentiveness and visuo-spatial impairment were indicative of delirium in both alert- or calmness and drowsiness.

SIGNIFICANCE OF RESULTS

The impairment in the cognitive domain, psychomotor retardation, and sleep-wake cycle disturbances correctly identified delirium irrespective of the level alertness. Further, inattentiveness and - to a lesser degree - visuo-spatial impairment could represent a specific marker for delirium in the intensive care setting meriting further evaluation.

Ultra-brief Screeners for Detecting Delirium Superimposed on Dementia

OBJECTIVE

Delirium superimposed on dementia (DSD) is common, morbid, and costly, yet frequently undiagnosed. Our study aimed to develop a brief screening test to improve health care worker recognition of DSD.

DESIGN/SETTING/PARTICIPANTS

Older hospitalized adults with dementia were prospectively enrolled from medical and surgical inpatient units of 3 hospitals (2 in Pennsylvania, 1 in Tennessee).

MEASURES

The reference standard delirium assessment used Confusion Assessment Method (CAM) criteria and was based on a structured interview including the Mini-Mental State Examination, interviewer observations, and medical record review. To develop the screening test, 1-, 2-, and 3-item combinations from the reference standard assessment were analyzed to determine their sensitivity and specificity in diagnosing delirium presence in a dementia population compared to the reference standard. For multiple-item screeners, error on 1 or more items was considered a positive screen.

RESULTS

Overall, 391 older adults with dementia were enrolled (mean age: 83.9 years, 71.1% female), and 95 (24.4%) developed DSD during their hospitalization, based on the reference standard. The best single-item screen for DSD was "What day of the week is it?" with 84% sensitivity [95% confidence interval (CI): 0.75, 0.91] and 41% specificity (CI: 0.35, 0.47). The best 2-item screen was "list the days of the week backwards" and "What day of the week is it?" with 93% sensitivity (CI: 0.85, 0.97) and 30% specificity (CI: 0.25, 0.36). The best 3-item screen was "list the days of the week backwards," "What type of place is this? [hospital]" and "Does the patient appear sleepy?" with 94% sensitivity (CI: 0.87, 0.98) and 42% specificity (CI: 0.36, 0.48).

CONCLUSIONS/IMPLICATIONS

We identified a 3-item DSD screener with excellent sensitivity but limited specificity. This screener can be used to quickly rule out DSD in populations with a high prevalence of dementia and is a promising step toward developing efficient tools for DSD recognition among care providers.

Performance on bedside tests of attention and organized thinking in patients with dementia free from delirium

ABSTRACTObjectives:Bedside tests of attention and organized thinking were performed in patients with cognitive impairment or dementia but without delirium, to provide estimates of false positive rates for detecting delirium superimposed on dementia (DSD).

DESIGN AND SETTING

This cross-sectional study was conducted in outpatients and institutionalized patients without delirium representing a wide spectrum of severity of cognitive impairments.

PARTICIPANTS

Patients with dementia or a cognitive disorder according to DSM IV criteria, after exclusion of (suspected) delirium according to DSM IV criteria.

MEASUREMENTS

Tests for inattention and disorganized thinking from the CAM-ICU were assessed.

RESULTS

The sample included 163 patients (mean age 83 years (SD 6; 64% women)), with Alzheimer's disease as most prevalent (45%) diagnosis and a mean MMSE-score of 16.8 (SD 7.5). False positive rates of the test of attention varied from 0.04 in patients with normal to borderline cognitive function to 0.8 in those with severe dementia. The false positive rate of the test of disorganized thinking was zero in the normal to borderline group, increasing to 0.67 in patients with severe dementia. When combining test results false positive rates decreased to 0.03 in patients with MMSE scores above 9.

CONCLUSION

Use of simple bedside tests of attention and organized thinking for the clinical diagnosis of DSD will result in high rates of false positive observations if used regardless of the severity of dementia. However, if test results are combined they may be useful to exclude DSD in patients with minimal to moderate degrees of dementia, but not in the severe group.

Attention, arousal and other rapid bedside screening instruments for delirium in older patients: a systematic review of test accuracy studies

Objective

delirium occurs frequently in frail patients but is easily missed. Screening with a rapid, easy-to-use and highly sensitive instrument might help improve recognition. The aim of this study was to review attention, arousal and other rapid bedside screening instruments for delirium in older patients.

Methods

a literature search was performed in PubMed, PsycINFO and Embase. We scrutinized forward citations in Google Scholar, and references of included articles and prior reviews. We included studies among older patients that investigated the sensitivity and specificity of delirium screening instruments that could be administered in 3 min or less, and did not require surrogate information. We extracted study characteristics, risk of bias, sensitivity and specificity.

Results

we identified 27 studies among 4,766 patients in hospitals and nursing homes. They tested many different single and several combined screening instruments. Prevalence of delirium varied between 4% and 57%. Only one study scored a low risk of bias on all domains. Sensitivity varied between 17% and 100%, and specificity between 38% and 99%. Of the 22 tests with sensitivity ≥90%, seven also had specificity ≥80% in older patients in general. These results were approximately reproduced for the Observational Scale of Level of Arousal (OSLA) and Richmond Agitation and Sedation Scale (RASS): sensitivity and specificity were >80%.

Conclusion

two arousal tests-OSLA and RASS-had reproduced high sensitivity and specificity in older patients. Nurses can administer these tests during daily interaction with patients. Test accuracy studies about rapid screening tools for delirium superimposed on dementia were scarce.

Validation of the 6-Item Cognitive Impairment Test and the 4AT test for combined delirium and dementia screening in older Emergency Department attendees

Background

screening for cognitive impairment in Emergency Department (ED) requires short, reliable tools.

Objective

to validate the 4AT and 6-Item Cognitive Impairment Test (6-CIT) for ED dementia and delirium screening.

Design

diagnostic accuracy study.

Setting/subjects

attendees aged ≥70 years in a tertiary care hospital’s ED.

Methods

trained researchers assessed participants using the Standardised Mini Mental State Examination, Delirium Rating Scale-Revised 98 and Informant Questionnaire on Cognitive Decline in the Elderly, informing ultimate expert diagnosis using Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria for dementia and delirium (reference standards). Another researcher blindly screened each participant, within 3 h, using index tests 4AT and 6-CIT.

Result

of 419 participants (median age 77 years), 15.2% had delirium and 21.5% had dementia. For delirium detection, 4AT had positive predictive value (PPV) 0.68 (95% confidence intervals: 0.58–0.79) and negative predictive value (NPV) 0.99 (0.97–1.00). At a pre-specified 9/10 cut-off (9 is normal), 6-CIT had PPV 0.35 (0.27–0.44) and NPV 0.98 (0.95–0.99).

Importantly, 52% of participants had no family present. A novel algorithm for scoring 4AT item 4 where collateral history is unavailable (score 4 if items 2–3 score ≥1; score 0 if items 1–3 score is 0) proved reliable; PPV 0.65 (0.54–0.76) and NPV 0.99 (0.97–1.00). For dementia detection, 4AT had PPV 0.39 (0.32–0.46) and NPV 0.94 (0.89–0.96); 6-CIT had PPV 0.46 (0.37–0.55) and NPV 0.94 (0.90–0.97).

Conclusion

6-CIT and 4AT accurately exclude delirium and dementia in older ED attendees. 6-CIT does not require collateral history but has lower PPV for delirium.