Predictors of agreement between general practitioner detection of dementia and the revised Cambridge Cognitive Assessment (CAMCOG-R)

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.

Swedish Clinical Professionals' Perspectives on Evaluating Cognitive and Communicative Function in Dementia

Objectives: This study investigated Swedish clinical professionals' experiences of diagnostic pathways in dementia, focusing on the assessment of cognitive and communicative abilities.Methods: Interdisciplinary teams in Memory Clinics, General Practitioners in Primary Health Care, and Speech Language Pathologists were interviewed. The transcripts were analyzed using qualitative Content Analysis.Results: The study sheds light upon the perceived barriers and facilitators of good practice, e.g. time and clinical collaborations. Perspectives among professionals vary as to how informal and formal information and procedures are to be integrated and weighted. External factors (e.g. physical proximity of professions) have considerable influence on information availability, transmission, and diagnostic processes. Communication impairment does not emerge as a clinical priority.Conclusions: Published clinical guidelines notwithstanding, there is in practice no "gold standard" regarding diagnostic processes. Reorganization of services that impact feasibility of cross-disciplinary contact may negatively impact diagnostics.Clinical implications: Interprofessional collaboration is impacted by many factors, e.g. physical proximity and availability of specific professions. In order to optimize collaboration in dementia diagnosis, communication channels between professions need to be optimized. Additionally, making clinical impressions and "gut-feelings" explicit could contribute valuable information to the diagnostic process.

Mobile memory clinic: implementing a nurse practitioner-led, collaborative dementia model of care within general practice

The limited capacity of secondary health services to address the increasing prevalence of dementia within the community draws attention to the need for an enhanced role for nurses working collaboratively with GPs in diagnosing and coordinating post-diagnostic care for patients with dementia. This study investigated the feasibility and acceptability of a nurse practitioner-led mobile memory clinic that was embedded within general practice and targeted to caring for patients and their carers in areas of socioeconomic disadvantage with poor access to specialist health services. Over the period from mid-2013 to mid-2014, 40 GPs referred 102 patients, with the nurse practitioner conducting assessments with 77 of these patients in their homes. Overall, there was a strong interest in this model of care by general practice staff, with the assessment and care provided by the nurse practitioner evaluated as highly acceptable by both patients and their carers. Nonetheless, there are financial and structural impediments to this model of care being implemented within the current Australian health service framework, necessitating further research investigating its cost-effectiveness and efficacy.

Diagnosis of dementia in Australia: a narrative review of services and models of care

Objective There is an impetus for the timely diagnosis of dementia to enable optimal management of patients, carers and government resources. This is of growing importance in the setting of a rising prevalence of dementia in an aging population. The Australian Clinical Practice Guidelines and Principles of Care for People with Dementia advocate referral to comprehensive memory services for dementia diagnosis, but in practice many patients may be diagnosed in other settings. The aim of the present study was to obtain evidence of the roles, effectiveness, limitations and accessibility of current settings and services available for dementia diagnosis in Australia. Methods A literature review was performed by searching Ovid MEDLINE using the terms 'dementia' AND 'diagnosis OR detection'. In addition, articles from pertinent sources, such as Australian government reports and relevant websites (e.g. Dementia Australia) were included in the review. Results Literature was found for dementia diagnosis across general practice, hospitals, memory clinics, specialists, community, care institutions and new models. General practitioners are patients' preferred health professionals when dealing with dementia, but gaps in symptom recognition and initiation of cognitive testing lead to underdiagnosis. Hospitals are opportunistic places for dementia screening, but time constraints and acute medical issues hinder efficient dementia diagnosis. Memory clinics offer access to multidisciplinary skills, demonstrate earlier dementia diagnosis and potential cost-effectiveness, but are disadvantaged by organisational complexities. Specialists have increased confidence in diagnosing dementia than generalists, but drawbacks include long wait lists. Aged care assessment teams (ACAT) are a potential service for dementia diagnosis in the community. A multidisciplinary model for dementia diagnosis in care institutions is potentially beneficial, but is time and cost intensive. New models with technology allow dementia diagnosis in rural regions. Conclusion Memory clinics are most effective for formal dementia diagnosis, but healthcare professionals in other settings play vital roles in recognising patients with dementia and initiating investigations and referrals to appropriate services. What is known about this topic? Delays in dementia diagnosis are common, and it is unclear where majority of patients receive a diagnosis of dementia in Australia. While the Australian Clinical Practice Guidelines and Principles of Care for People with Dementia advocate referrals to services such as memory clinics for comprehensive assessment and diagnosis of dementia, such services may have limited capacity and may not be readily accessible to all. What does this paper add? This paper presents an overview of the various settings and services available for dementia diagnosis in Australia including evidence of the roles, accessibility, effectiveness and limitations of each setting. What are the implications for practitioners? This concerns a disease that is highly prevalent and escalating, and highlights the roles for practitioners in various settings including general practices, acute hospitals, specialist clinics, community and nursing homes. In particular, it discusses the potential roles, advantages and challenges of dementia diagnosis in each setting.

Understanding diagnostic settings and carer experiences for dementia diagnosis in Australia

BACKGROUND

Australian guidelines advocate referral to comprehensive memory services for dementia diagnosis, but many patients may be diagnosed elsewhere.

AIMS

To determine common settings for dementia diagnosis in Australia and to compare patient and carer experience between settings.

METHODS

Exploratory cross-sectional study of patients with dementia admitted to a Melbourne sub-acute hospital. Patients who had capacity to participate were included; carers were recruited for patients without capacity. Participants completed an interviewer-administered survey which asked them to recall the diagnostic setting, discussions about diagnosis and management (clinical care) and overall experience of diagnosis. Descriptive statistics were applied and open-ended questions were analysed using inductive and deductive coding approaches.

RESULTS

From 81 eligible participants, 74 consented to participate (one patient, 74 carers). Participants reported dementia diagnosis occurred a median of 24 months before interview, in the following settings: hospitals (31.3%), private specialist clinics (29.7%), memory clinics (14.9%), general practice (13.5%), community health services (9.5%) and residential care (1.4%). Recall of discussions about dementia-modulating medications was higher in participants diagnosed in memory clinics and private specialist clinics (70%) compared to other settings (15%) (P < 0.001). Discussion about living circumstances was highest in hospitals (87% vs 40%) (P < 0.001). One third of participants reported dissatisfaction with their experience. Reported satisfaction was highest for memory clinics.

CONCLUSION

Results suggest majority of people with dementia are diagnosed outside memory services. Significant variability exists in experiences between services, with a high proportion of participants expressing dissatisfaction with their experience with dementia diagnosis. Strategies to standardise diagnosis of dementia, measure and improve quality of care across all settings are required.

Psychosocial stress associated with memory performance in older South African adults

Older adults with past or current chronic stress exposure perform poorly on memory assessments and are at higher risk for Alzheimer's disease (AD). In low- or middle-income countries, many older adults are, or have been, exposed to stress-provoking events. Few published studies examine such populations, however, and few take multiple measures of stress. In a sample of South African older adults with mild-to-moderate AD (n = 65) and healthy controls (n = 69), we assessed relations between stress (psychosocial and physiological), memory performance, and patient status. Participants, all aged > 60, were administered the Perceived Stress Scale (a questionnaire assessing subjective psychosocial stress) and the Cambridge Cognitive Examination-Revised (CAMCOG-R; a test battery measuring performance across several cognitive domains). We measured their salivary cortisol concentrations as a proxy for physiological stress. Patients reported significantly higher levels of psychosocial stress than controls, p = .008. Logistic regression showed that psychosocial stress, but not cortisol, predicted AD patient status. CAMCOG-R Memory subscale scores were significantly associated with psychosocial stress, r = -.18, p = .040, but not with cortisol levels. These findings are the first on the topic to emerge from a low-or middle-income country. We replicated findings from previous studies conducted in high-income countries, with data supporting predictions derived from the glucocorticoid cascade/neurotoxicity hypothesis. The results suggest that clinical interventions focused on increasing resilience of older adults to effects of chronic stress may help protect against declining memory performance and reduce the risk for AD.

Effectiveness of a peer-mediated educational intervention in improving general practitioner diagnostic assessment and management of dementia: a cluster randomised controlled trial

OBJECTIVE

Test effectiveness of an educational intervention for general practitioners (GPs) on quality of life and depression outcomes for patients.

DESIGN

Double-blind, cluster randomised controlled trial.

SETTING

General practices in Australia between 2007 and 2010.

PARTICIPANTS

General practices were randomly allocated to the waitlist (n=37) or intervention (n=66) group, in a ratio of 1:2. A total of 2030 (1478 intervention; 552 waitlist) community-dwelling participants aged 75 years or older were recruited via 168 GPs (113 intervention; 55 waitlist).

INTERVENTIONS

A practice-based academic detailing intervention led by a peer educator that included: (1) training in use of the GP assessment of cognition dementia screening instrument; (2) training in diagnosis and management based on Royal Australian College of General Practitioners Dementia Guidelines; (3) addressing GPs' barriers to dementia diagnosis; and (4) a business case outlining a cost-effective dementia assessment approach.

OUTCOME MEASURES

Primary outcome measures were patient quality of life and depression; secondary outcome measures were: (1) sensitivity and specificity of GP identification of dementia; (2) referral to medical specialists and/or support services; (3) patient satisfaction with care; and (4) carer quality of life, depression and satisfaction with care.

RESULTS

The educational intervention had no significant effect on patient quality of life or depression scores after 12 months. There were however improvements in secondary outcome measures including sensitivity of GP judgement of dementia (p=0.002; OR 6.0, 95% CI 1.92 to 18.73), satisfaction with GP communication for all patients (p=0.024; mean difference 2.1, 95% CI 0.27 to 3.93) and for patients with dementia (p=0.007; mean difference 7.44, 95% CI 2.02 to 12.86) and enablement of carers (p=0.0185; mean difference 24.77, 95% CI 4.15 to 45.40).

CONCLUSION

Practice-based academic detailing did not improve patient quality of life or depression scores but did improve detection of dementia in primary care and patient satisfaction with GP communication.

TRIAL REGISTRATION NUMBER

ACTRN12607000117415; Pre-results.

Screening for Dementia in Primary Care: A Comparison of the GPCOG and the MMSE

BACKGROUND/AIMS

The General Practitioner Assessment of Cognition (GPCOG) is a brief cognitive test. This study compared the GPCOG to the Mini-Mental State Examination (MMSE), the most widely used test, in terms of their ability to detect likely dementia in primary care.

METHODS

General practitioners across three states in Australia recruited 2,028 elderly patients from the community. A research nurse administered the GPCOG and the MMSE, as well as the Cambridge Examination for Mental Disorders of the Elderly Cognitive Scale-Revised that we used to define likely dementia.

RESULTS

Overall, the GPCOG and the MMSE were similarly effective at detecting likely dementia. The GPCOG, however, had a higher sensitivity than the MMSE when using published cutpoints.

CONCLUSION

The GPCOG is an effective screening tool for dementia in primary care. It appears to be a viable alternative to the MMSE, whilst also requiring less time to administer.

An evaluation of the additional benefit of population screening for dementia beyond a passive case-finding approach

OBJECTIVE

General practitioners (GPs) fail to identify more than 50% of dementia cases using the existing passive case-finding approach. Using data from the "Ageing in General Practice" study, we sought to establish the additional benefit of screening all patients over the age of 75 for dementia beyond those patients already identified by passive case-finding.

METHOD

Patients were classified as "case-finding" (n = 425) or "screening" (n = 1006) based on their answers to four subjective memory related questions or their GP's clinical judgement of their dementia status. Cognitive status of each patient was formally assessed by a research nurse using the Cambridge Cognition Examination (CAMCOG-R). Patients then attended their usual GP for administration of the GP assessment of Cognition (GPCOG) dementia screening instrument, and follow-up care and/or referral as necessary in light of the outcome.

RESULTS

The prevalence of dementia was significantly higher in the case-finding group (13.6%) compared to the screening group (4.6%; p < 0.01). The GPCOG had a positive predictive value (PPV) of 61% in the case-finding group and 39% in the screening group; negative predictive value was >95% in both groups. GPs and their patients both found the GPCOG to be an acceptable cognitive assessment tool. The dementia cases missed via case-finding were younger (p = 0.024) and less cognitively impaired (p = 0.020) than those detected.

CONCLUSION

There is a very limited benefit of screening for dementia, as most people with dementia could be detected using a case-finding approach, and considerable potential for social and economic harm because of the low PPV associated with screening.

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.

Attitudes to Alzheimer's disease testing of Australian general practice patients: a cross-sectional questionnaire-based study

OBJECTIVE

In view of proposed screening for presymptomatic Alzheimer's disease (AD) with advanced imaging, and blood and cerebral spinal fluid analysis, we aimed to establish levels, and associations, of acceptance of AD testing modalities by general practice patients.

METHODS

A cross-sectional questionnaire-based study of consecutive patients (aged 50 years and over) of general practices of an Australian practice-based research network was used. The questionnaire elicited demographic data and attitudes to screening for other diseases and included the screening acceptance domain of the Perceptions Regarding Investigational Screening for Memory in Primary Care (PRISM-PC) instrument. This assesses receptivity to modalities of testing for AD: short questionnaire, blood test, cerebral imaging, and annual physician examination. Reflecting speculation of possible future AD diagnostic methods, an item regarding testing cerebral spinal fluid was also included. Associations of PRISM-PC scores were analyzed with multiple linear regression.

RESULTS

Of 489 participants (response rate 87%), 66.2% would like to know if they had AD. Participants were more accepting of testing modalities that were noninvasive or familiar (questionnaire, physician's examination, and blood test) as opposed to cerebral imaging or lumbar puncture. Attitudes to AD testing are influenced by a positive attitude to disease screening in general. Patients with a self-perceived higher risk of AD were less accepting of testing, as were participants with an educational level of junior high school (10 school years) or less.

CONCLUSIONS

This study demonstrates that a majority of patients would like to know if they have AD. Acceptability of testing modalities, however, varies. Noninvasive, familiar methods are more acceptable.

Impact of multiple low-level anticholinergic medications on anticholinergic load of community-dwelling elderly with and without dementia

BACKGROUND

Elderly people, particularly those with dementia, are sensitive to adverse anticholinergic drug effects. This study examines the prevalence of anticholinergic medication, and anticholinergic load and its predictors, in community-dwelling elderly patients (aged 75 years and older) in Australia.

METHODS

A research nurse visited the home of each participant (n = 1,044), compiled a list of current medications, and assessed participants' cognitive status using a subsection of the revised Cambridge Examination for Mental Disorders of the Elderly (CAMCOG-R). Anticholinergic load was determined for each patient using the Anticholinergic Drug Scale (ADS).

RESULTS

Multivariate analysis identified several patient factors that were associated with higher anticholinergic burden, including polypharmacy (i.e. taking five or more medications) (p < 0.001), increasing age (p = 0.018), CAMCOG-R dementia (p = 0.003), depression (p = 0.003), and lower physical quality of life (p < 0.001). The dementia group (n = 86) took a significantly higher number of medications (4.6 vs. 3.9; p = 0.04), and had a significantly higher anticholinergic load (1.5 vs. 0.8; p = 0.002) than those without dementia (n = 958). Approximately 60% of the dementia group and 40% of the non-dementia group were receiving at least one anticholinergic drug. This difference was due to the higher proportion of dementia patients taking level 1 (potentially anticholinergic) (p = 0.002) and level 3 (markedly anticholinergic) (p = 0.005) drugs.

CONCLUSIONS

There is considerable scope for the improvement of prescribing practices in the elderly, and particularly those with dementia. Importantly, level 1 anticholinergics have been identified as major contributors to the anticholinergic load in people with dementia. Longitudinal studies are required to determine the effects of increased and decreased anticholinergic load on cognitive function and other clinical outcomes for people with dementia.