A combination of tests for the diagnosis of dementia had a significant diagnostic value

Clinical judgement by primary care physicians for the diagnosis of all-cause dementia or cognitive impairment in symptomatic people

BACKGROUND

In primary care, general practitioners (GPs) unavoidably reach a clinical judgement about a patient as part of their encounter with patients, and so clinical judgement can be an important part of the diagnostic evaluation. Typically clinical decision making about what to do next for a patient incorporates clinical judgement about the diagnosis with severity of symptoms and patient factors, such as their ideas and expectations for treatment. When evaluating patients for dementia, many GPs report using their own judgement to evaluate cognition, using information that is immediately available at the point of care, to decide whether someone has or does not have dementia, rather than more formal tests.

OBJECTIVES

To determine the diagnostic accuracy of GPs' clinical judgement for diagnosing cognitive impairment and dementia in symptomatic people presenting to primary care. To investigate the heterogeneity of test accuracy in the included studies.

SEARCH METHODS

We searched MEDLINE (Ovid SP), Embase (Ovid SP), PsycINFO (Ovid SP), Web of Science Core Collection (ISI Web of Science), and LILACs (BIREME) on 16 September 2021.

SELECTION CRITERIA

We selected cross-sectional and cohort studies from primary care where clinical judgement was determined by a GP either prospectively (after consulting with a patient who has presented to a specific encounter with the doctor) or retrospectively (based on knowledge of the patient and review of the medical notes, but not relating to a specific encounter with the patient). The target conditions were dementia and cognitive impairment (mild cognitive impairment and dementia) and we included studies with any appropriate reference standard such as the Diagnostic and Statistical Manual of Mental Disorders (DSM), International Classification of Diseases (ICD), aetiological definitions, or expert clinical diagnosis.

DATA COLLECTION AND ANALYSIS

Two review authors screened titles and abstracts for relevant articles and extracted data separately with differences resolved by consensus discussion. We used QUADAS-2 to evaluate the risk of bias and concerns about applicability in each study using anchoring statements. We performed meta-analysis using the bivariate method.

MAIN RESULTS

We identified 18,202 potentially relevant articles, of which 12,427 remained after de-duplication. We assessed 57 full-text articles and extracted data on 11 studies (17 papers), of which 10 studies had quantitative data. We included eight studies in the meta-analysis for the target condition dementia and four studies for the target condition cognitive impairment. Most studies were at low risk of bias as assessed with the QUADAS-2 tool, except for the flow and timing domain where four studies were at high risk of bias, and the reference standard domain where two studies were at high risk of bias. Most studies had low concern about applicability to the review question in all QUADAS-2 domains. Average age ranged from 73 years to 83 years (weighted average 77 years). The percentage of female participants in studies ranged from 47% to 100%. The percentage of people with a final diagnosis of dementia was between 2% and 56% across studies (a weighted average of 21%). For the target condition dementia, in individual studies sensitivity ranged from 34% to 91% and specificity ranged from 58% to 99%. In the meta-analysis for dementia as the target condition, in eight studies in which a total of 826 of 2790 participants had dementia, the summary diagnostic accuracy of clinical judgement of general practitioners was sensitivity 58% (95% confidence interval (CI) 43% to 72%), specificity 89% (95% CI 79% to 95%), positive likelihood ratio 5.3 (95% CI 2.4 to 8.2), and negative likelihood ratio 0.47 (95% CI 0.33 to 0.61). For the target condition cognitive impairment, in individual studies sensitivity ranged from 58% to 97% and specificity ranged from 40% to 88%. The summary diagnostic accuracy of clinical judgement of general practitioners in four studies in which a total of 594 of 1497 participants had cognitive impairment was sensitivity 84% (95% CI 60% to 95%), specificity 73% (95% CI 50% to 88%), positive likelihood ratio 3.1 (95% CI 1.4 to 4.7), and negative likelihood ratio 0.23 (95% CI 0.06 to 0.40). It was impossible to draw firm conclusions in the analysis of heterogeneity because there were small numbers of studies. For specificity we found the data were compatible with studies that used ICD-10, or applied retrospective judgement, had higher reported specificity compared to studies with DSM definitions or using prospective judgement. In contrast for sensitivity, we found studies that used a prospective index test may have had higher sensitivity than studies that used a retrospective index test.

AUTHORS' CONCLUSIONS

Clinical judgement of GPs is more specific than sensitive for the diagnosis of dementia. It would be necessary to use additional tests to confirm the diagnosis for either target condition, or to confirm the absence of the target conditions, but clinical judgement may inform the choice of further testing. Many people who a GP judges as having dementia will have the condition. People with false negative diagnoses are likely to have less severe disease and some could be identified by using more formal testing in people who GPs judge as not having dementia. Some false positives may require similar practical support to those with dementia, but some - such as some people with depression - may suffer delayed intervention for an alternative treatable pathology.

The incremental value of neuropsychological assessment: A critical review

Objective: The purpose of this critical review was to evaluate the current state of research regarding the incremental value of neuropsychological assessment in clinical practice, above and beyond what can be accounted for on the basis of demographic, medical, and other diagnostic variables. The focus was on neurological and other medical conditions across the lifespan where there is known risk for presence or future development of cognitive impairment.Method: Eligible investigations were group studies that had been published after 01/01/2000 in English in peer-reviewed journals and that had used standardized neuropsychological measures and reported on objective outcome criterion variables. They were identified through PubMed and PsychInfo electronic databases on the basis of predefined specific selection criteria. Reference lists of identified articles were also reviewed to identify potential additional sources. The Grades of Recommendation, Assessment, Development and Evaluation Working Group's (GRADE) criteria were used to evaluate quality of studies.Results: Fifty-six studies met the final selection criteria, including 2 randomized-controlled trials, 9 prospective cohort studies, 12 retrospective cohort studies, 21 inception cohort studies, 2 case control studies, and 10 case series studies. The preponderance of the evidence was strongly supportive with regard to the incremental value of neuropsychological assessment in the care of persons with mild cognitive impairment/dementia and traumatic brain injury. Evidence was moderately supportive with regard to stroke, epilepsy, multiple sclerosis, and attention-deficit/hyperactivity disorder. Participation in neuropsychological evaluations was also associated with cost savings.Conclusions: Neuropsychological assessment can improve both diagnostic classification and prediction of long-term daily-life outcomes in patients across the lifespan. Future high-quality prospective cohort studies and randomized-controlled trials are necessary to demonstrate more definitively the incremental value of neuropsychological assessment in the management of patients with various neurological and other medical conditions.

Validity of a novel computerized screening test system for mild cognitive impairment

ABSTRACTBackground:The mobile screening test system for screening mild cognitive impairment (mSTS-MCI) was developed for clinical use. However, the clinical usefulness of mSTS-MCI to detect elderly with MCI from those who are cognitively healthy has yet to be validated. Moreover, the comparability between this system and traditional screening tests for MCI has not been evaluated.

OBJECTIVE

The purpose of this study was to examine the validity and reliability of the mSTS-MCI and confirm the cut-off scores to detect MCI.

METHOD

The data were collected from 107 healthy elderly people and 74 elderly people with MCI. Concurrent validity was examined using the Korean version of Montreal Cognitive Assessment (MoCA-K) as a gold standard test, and test-retest reliability was investigated using 30 of the study participants at four-week intervals. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were confirmed through Receiver Operating Characteristic (ROC) analysis, and the cut-off scores for elderly people with MCI were identified.

RESULTS

Concurrent validity showed statistically significant correlations between the mSTS-MCI and MoCA-K and test-rests reliability indicated high correlation. As a result of screening predictability, the mSTS-MCI had a higher NPV than the MoCA-K.

CONCLUSIONS

The mSTS-MCI was identified as a system with a high degree of validity and reliability. In addition, the mSTS-MCI showed high screening predictability, indicating it can be used in the clinical field as a screening test system for mild cognitive impairment.

Towards improving diagnosis of memory loss in general practice: TIMeLi diagnostic test accuracy study protocol

Background

People with cognitive problems, and their families, report distress and uncertainty whilst undergoing evaluation for dementia and perceive that traditional diagnostic evaluation in secondary care is insufficiently patient centred. The James Lind Alliance has prioritised research to investigate the role of primary care in supporting a more effective diagnostic pathway, and the topic is also of interest to health commissioners. However, there are very few studies that investigate the accuracy of diagnostic tests for dementia in primary care.

Methods

We will conduct a prospective diagnostic test accuracy study to evaluate the accuracy of a range of simple tests for diagnosing all-cause-dementia in symptomatic people aged over 70 years who have consulted with their general practitioner (GP). We will invite eligible people to attend a research clinic where they will undergo a range of index tests that a GP could perform in the surgery and also be assessed by a specialist in memory disorders at the same appointment. Participating GPs will request neuroimaging and blood tests and otherwise manage patients in line with their usual clinical practice. The reference standard will be the consensus judgement of three experts (neurologist, psychiatrist and geriatrician) based on information from the specialist assessment, GP records and investigations, but not including items in the index test battery. The target condition will be all-cause dementia but we will also investigate diagnostic accuracy for sub-types where possible. We will use qualitative interviews with patients and focus groups with clinicians to help us understand the acceptability and feasibility of diagnosing dementia in primary care using the tests that we are investigating.

Discussion

Our results will help clinicians decide on which tests to perform in someone where there is concern about possible dementia and inform commissioning of diagnostic pathways.

Clinical history for diagnosis of dementia in men: Caerphilly Prospective Study

BACKGROUND

Diagnosis of dementia often requires specialist referral and detailed, time-consuming assessments.

AIM

To investigate the utility of simple clinical items that non-specialist clinicians could use, in addition to routine practice, to diagnose all-cause dementia syndrome.

DESIGN AND SETTING

Cross-sectional diagnostic test accuracy study. Participants were identified from the electoral roll and general practice lists in Caerphilly and adjoining villages in South Wales, UK.

METHOD

Participants (1225 men aged 45-59 years) were screened for cognitive impairment using the Cambridge Cognitive Examination, CAMCOG, at phase 5 of the Caerphilly Prospective Study (CaPS). Index tests were a standardised clinical evaluation, neurological examination, and individual items on the Informant Questionnaire for Cognitive Disorders in the Elderly (IQCODE).

RESULTS

Two-hundred and five men who screened positive (68%) and 45 (4.8%) who screened negative were seen, with 59 diagnosed with dementia. The model comprising problems with personal finance and planning had an area under the curve (AUC) of 0.92 (95% confidence interval [CI] = 0.86 to 0.97), positive likelihood ratio (LR+) of 23.7 (95% CI = 5.88 to 95.6), negative likelihood ratio (LR-) of 0.41 (95% CI = 0.27 to 0.62). The best single item for ruling out was no problems learning to use new gadgets (LR- of 0.22, 95% CI = 0.11 to 0.43).

CONCLUSION

This study found that three simple questions have high utility for diagnosing dementia in men who are cognitively screened. If confirmed, this could lead to less burdensome assessment where clinical assessment suggests possible dementia.

Computerized cognitive testing for older adults: a review

OBJECTIVE

This article is a review of computerized tests and batteries used in the cognitive assessment of older adults.

METHOD

A literature search on Medline followed by cross-referencing yielded a total of 76 citations.

RESULTS

Seventeen test batteries were identified and categorized according to their scope. Computerized adaptive testing (CAT) and the Cambridge Cognitive Examination CAT battery as well as 3 experimental batteries and an experimental test are discussed in separate sections. All batteries exhibit strengths associated with computerized testing such as standardization of administration, accurate measurement of many variables, automated record keeping, and savings of time and costs. Discriminant validity and test-retest reliability were well documented for most batteries while documentation of other psychometric properties varied.

CONCLUSION

The large number of available batteries can be beneficial to the clinician or researcher; however, care should be taken in order to choose the correct battery for each application.

Computerized Neurocognitive Test (CNT) in mild cognitive impairment and Alzheimer's disease

Currently, computerized batteries are of great value in detecting cognitive impairment. This aim of this review was to compare the computerized neurocognitive batteries used in most studies with cognitive decline over the last 10 years. Using the search words computerized cognitive assessment with: dementia, mild cognitive impairment, and Alzheimer's disease, the CogState, CNS Vital Sings, COGDRAS and Mindstreams batteries were retrieved.

Diagnosing dementia: no easy job

Background

From both clinical experience and research we learned that in complex progressive disorders such as dementia, diagnosis includes multiple steps, each with their own clinical and research characteristics.

Discussion

Diagnosing starts with a trigger phase in which the GP gradually realizes that dementia may be emerging. This is followed by a disease-oriented diagnosis and subsequently a care -oriented diagnosis. In parallel the GP should consider the consequences of this process for the caregiver and the interaction between both. As soon as a comprehensive diagnosis and care plan are available, monitoring follows.

Summary

We propose to split the diagnostic process into four diagnostic steps, followed by a monitoring phase. We recommend to include these steps when designing studies on screening, diagnosis and monitoring of patients with dementia and their families.

Clock drawing performance in a community-dwelling population: Normative data for Japanese subjects

OBJECTIVES

The Clock Drawing Test (CDT) is commonly used for cognitive screening. The purpose of this study is to develop normative data for the CDT for the Japanese community-dwelling population, using the method of Freedman. This study also investigates the effect of demographic factors on the performance of the subjects in this task.

METHODS

We administered the CDT and the Mini-Mental State Examination (MMSE) to 873 volunteers. Using a multiple linear regression analysis, we found a gender difference in the free-drawn condition.

RESULTS

A detrimental effect of age was observed in the free-drawn and pre-drawn conditions. The years of education affected the CDT in the examiner 2 condition. Correlations of the MMSE with each of the five conditions of the CDT were significant, further validating this test.

CONCLUSIONS

Our study provides preliminary normative data for the Japanese population stratified by the age and level of education. However, interpretation of our results was hampered by the large variability in the performance of the subjects and the possibility of a selection bias. Thus, additional studies will be necessary to further characterise the CDT scores for the Japanese community.

Frailty: an emerging concept for general practice

Ageing of the population in western societies and the rising costs of health and social care are refocusing health policy on health promotion and disability prevention among older people. However, efforts to identify at-risk groups of older people and to alter the trajectory of avoidable problems associated with ageing by early intervention or multidisciplinary case management have been largely unsuccessful. This paper argues that this failure arises from the dominance in primary care of a managerial perspective on health care for older people, and proposes instead the adoption of a clinical paradigm based on the concept of frailty. Frailty, in its simplest definition, is vulnerability to adverse outcomes. It is a dynamic concept that is different from disability and easy to overlook, but also easy to identify using heuristics (rules of thumb) and to measure using simple scales. Conceptually, frailty fits well with the biopsychosocial model of general practice, offers practitioners useful tools for patient care, and provides commissioners of health care with a clinical focus for targeting resources at an ageing population.

Combined instruments for the screening of dementia in older people with low Education

OBJECTIVE: To determine which combination of cognitive tests and informant reports can improve the diagnostic accuracy of dementia screening in low educated older people. METHOD: Patients with mild to moderate dementia (n=34) according to ICD-10 and DSM-III-R criteria and 59 older controls were assessed with the Mini-Mental State Examination (MMSE) and the Fuld Object Memory Evaluation (FOME). Informants were assessed using the Informant Questionnaire on Cognitive Decline in the Elderly and the Bayer-Activities of Daily Living Scale. RESULTS: The 4 instruments combined with the mixed rule correctly classified 100% and the logistic regression (weighted sum) classified 95.7% of subjects. The weighted sum had a significantly larger ROC area compared to MMSE (p=0.008) and FOME (p=0.023). The specificity of the tested combinations was superior to the MMSE alone (p=0.002). CONCLUSIONS: Cognitive tests combined with informant reports can improve the screening of mild to moderate dementia in low educated older people.

Status of computerized cognitive testing in aging: a systematic review

BACKGROUND

Early detection of cognitive decline in the elderly has become of heightened importance in parallel with the recent advances in therapeutics. Computerized assessment might be uniquely suited to early detection of changes in cognition in the elderly. We present here a systematic review of the status of computer-based cognitive testing, focusing on detection of cognitive decline in the aging population.

METHODS

All studies purporting to assess or detect age-related changes in cognition or early dementia/mild cognitive impairment by means of computerized testing were included. Each test battery was rated on availability of normative data, level of evidence for test validity and reliability, comprehensiveness, and usability. All published studies relevant to a particular computerized test were read by a minimum of two reviewers, who completed rating forms containing the above mentioned criteria.

RESULTS

Of the 18 test batteries identified from the initial search, 11 were appropriate to cognitive testing in the elderly and were subjected to systematic review. Of those 11, five were either developed specifically for application with the elderly or have been used extensively with that population. Even within the computerized testing genre, great variability existed in manner of administration, ranging from fully examiner-administered to fully self-administered. All tests had at least minimal reliability and validity data, commonly reported in peer-reviewed articles. However, level of rigor of validity testing varied widely.

CONCLUSION

All test batteries exhibited some of the strengths of computerized cognitive testing: standardization of administration and stimulus presentation, accurate measures of response latencies, automated comparison in real time with an individual's prior performance as well as with age-related norms, and efficiencies of staffing and cost. Some, such as the Mild Cognitive Impairment Screen, adapted complicated scoring algorithms to enhance the information gathered from already existing tests. Others, such as CogState, used unique interfaces and subtests. We found that although basic indices of psychometric properties were typically addressed, sufficient variability exists that currently available computerized test batteries must be judged on a case-by-case basis.

Cognitive test performance and brain pathology

BACKGROUND

Cognitive impairment, assessed using paper-and-pencil tests, occurs with multiple syndromes, including heart failure; however, relationships between test performance and brain injury are unclear.

OBJECTIVES

To determine the extent of brain injury assessed by magnetic resonance T2 relaxometry procedures in a mixed sample with cognitive impairment as measured by the Mini-Mental State Examination, Trailmaking Test parts A (TMT-A) and B (TMT-B), and the Watson Clock-Drawing Test (CDT).

METHODS

A comparative design was used with a convenience sample of 66 participants (age 48.2 +/- 8.4 years, 41 males, 52 right-handed). Normal and abnormal performances on cognitive tests were compared using T2 relaxation values across the brain (p < .005). Fifty-four of the participants were healthy, and 12 had heart failure (New York Heart Association classes II-III, left ventricular ejection fraction <0.40).

RESULTS

All participants scored normally on the Mini-Mental State Examination; thus, this test was excluded from further analysis. Abnormal cognitive scores were found in 14-20% of the participants, with significant brain injury appearing in participants with abnormal test scores. Injured structures included frontal, temporal, parietal, insular, and cingulate cortices; corpus callosum; and caudate. The CDT results showed the greatest extent of structural injury. The TMT-A test demonstrated relationships to specific injury sites, whereas the TMT-B showed relationships only to isolated areas of damage.

DISCUSSION

The findings suggest that paper-and-pencil cognitive tests relate to injury in brain structures, with CDT values relating to the greatest extent of injury. Specific damage sites may correlate with unique tests, such as TMT-A. Specialized tests should be developed that would indicate neural injury in specific areas.

The use of imperfect diagnostic tests had an impact on prevalence estimation

OBJECTIVE

Problems arising with the estimation of sensitivity and specificity when two imperfect diagnostic tests are applied are widely discussed. Effects on the estimation of prevalence may be of importance as well. Different methods of dealing with two or more imperfect tests and unknown reference standard are contrasted with regard to their implications on prevalence estimation: discrepant analysis, composite reference standards, and latent class models.

STUDY DESIGN AND SETTING

Prospective epidemiological multicenter study to determine the prevalence of respiratory syncytial virus in children with lower respiratory tract infections. A subsample of 1,003 patients from a hospital population and from a practice population is considered. Virus isolation, polymerase chain reaction, and rapid antigen test had been applied.

RESULTS

Prevalence estimates obtained under various assumptions ranged from 0.263 to 0.386 in the hospital population and from 0.214 to 0.277 in the practice population.

CONCLUSION

Estimation procedures involving a resolver test applied to some but not all cells are at risk of introducing a serious bias in prevalence estimation as well as in the estimation of test accuracy parameters. Estimation via latent class modeling may be more useful, but care should be taken regarding the underlying assumptions.