Screening older Latinos for dementia in the primary care setting

Diagnosing Alzheimer's disease: Which dementia screening test to use in elderly Puerto Ricans with mild cognitive impairment and early Alzheimer's disease?

Typically, Alzheimer's disease (AD) diagnosis is not made at its earliest period, for instance, at mild cognitive impairment (MCI) and early AD (E-AD). Our study aims to demonstrate a correlation between the screening tools, including the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Clinical Dementia Rating (CDR), and the biological biomarkers in the cerebrospinal fluid (CSF) amyloid beta 1-42 (Aβ42), phosphorylated tau (p-tau) proteins and total tau (t-tau)/Aβ42 ratio in Puerto Ricans > 55 years old with MCI and E-AD. We evaluated 30 participants, including demographics, memory scales, and CSF biomarkers. Twenty-eight CSF biomarkers (Aβ42, p-tau protein, and t-tau/Aβ42 ratio) were analyzed using the Meso Scale Discovery Platform (MSD). Associations between memory scales (MoCA, MMSE, CDR) and CSF markers were performed using Spearman rho correlation. Our study revealed a statistical association favoring a direct relationship between MMSE and MoCA with t-tau/Aβ42 ratio in CSF (P = 0.022, P = 0.035, respectively). We found a trend toward significance with an inverse relationship with MMSE and Aβ42 (P = 0.069) and a direct relationship with MMSE and p-tau (P = 0.098). MMSE and MoCA screening tests were identified with a statistically significant association with the CSF biomarkers, specifically t-tau/Aβ42 ratio, in elderly Puerto Ricans with MCI and E-AD. Puerto Ricans > 55 years old with MCI and E-AD could be screened confidently with MMSE and MoCA for a higher likelihood of earlier detection and, thus, initiation of disease-modifying treatment and prompt non-pharmacological interventions.

A systematic review and meta-analysis of studies on screening for mild cognitive impairment in primary healthcare

BACKGROUND

Cognitive disorders and dementia have an important effect on individual independence and orientation. According to the Alzheimer's Disease International (ADI) 75% of people with dementia are not diagnosed; this may be as high as 90% in some low- and middle-income countries. This systematic review and meta-analysis aimed to identify the test performance of screening tools and compare them pairwise. The findings of our study can support countries in planning to establish and care for mild cognitive impairment in primary health centers.

METHODS

Medline (PubMed), Scopus, Cochrane, Dare, All EBM Reviews, CRD (OVID), and Proquest were searched from 2012 to November 2021. The risk of bias was assessed through the QUADAS-2 instrument. Given the high heterogeneity between studies, a random-effects model was used to calculate the pooled effect sizes for diagnostic accuracy measures (sensitivity, specificity, and area under curve indices). I² test was used for assessing heterogeneity and predefined subgroup analyses were performed using participants' age, country's income, and sample size of studies.

RESULTS

A systematic search identified 18,132 records, of which, 20 studies were included in the quality assessment, and six were included in quantitative analysis. None of the studies had examined the feasibility or efficiency of mass screening. According to a pairwise comparison, IQCODE, AD8 and GPCOG showed equal or better diagnostic performance relative to the MMSE in terms of sensitivity and specificity. The random-effect model for the MMSE showed the pooled sensitivity equal to 0.73 (95% CI 0.57-0.90), the pooled specificity equal to 0.83 (95% CI 0.75-0.90), and the pooled AUC equal to 0.88 (95% CI 0.83-0.93).

CONCLUSION

Several benefits have been attached to short tests making them a suitable choice for use in primary healthcare settings. Considering factors such as accuracy, time of application, ease of scoring, and utilization charges, tests such as IQCODE, AD8, and GPCOG or appropriate combination with counterpart tools seem to be good alternatives to the use of the MMSE in primary care.

The Utility of Cognitive Screeners in the Detection of Dementia Spectrum Disorders in Spanish-Speaking Populations

Increasing rates of dementia spectrum disorders among Spanish-speaking geriatric populations necessitate the development of culturally appropriate cognitive screening tests that can identify neurodegenerative disorders in their earliest stages when emerging disease-modifying treatments are most likely to be effective. This scoping review identified 26 brief Spanish language cognitive screening tools (<20 minutes) by searching academic databases using a combination of search terms. Results suggest that the Mini-Mental Status Examination and Montreal Cognitive Assessment appear to be less valid than other screeners. Instruments such as the 7-Minute Screen and Mini-Cog evidence higher classification rates of dementia, while Phototest detected mild cognitive impairment at higher rates more consistently than other screeners. Different sensitivity and specificity outcomes and cutoffs were observed when the same cognitive screener was evaluated in different countries. Results indicate that it is imperative to increase nation-specific validation and normative data for these instruments to best serve diverse populations.

A Systematic Review of Neuropsychological Tests for the Assessment of Dementia in Non-Western, Low-Educated or Illiterate Populations

OBJECTIVE

Neuropsychological tests are important instruments to determine a cognitive profile, giving insight into the etiology of dementia; however, these tests cannot readily be used in culturally diverse, low-educated populations, due to their dependence upon (Western) culture, education, and literacy. In this review we aim to give an overview of studies investigating domain-specific cognitive tests used to assess dementia in non-Western, low-educated populations. The second aim was to examine the quality of these studies and of the adaptations for culturally, linguistically, and educationally diverse populations.

METHOD

A systematic review was performed using six databases, without restrictions on the year or language of publication.

RESULTS

Forty-four studies were included, stemming mainly from Brazil, Hong Kong, Korea, and considering Hispanics/Latinos residing in the USA. Most studies focused on Alzheimer's disease (n = 17) or unspecified dementia (n = 16). Memory (n = 18) was studied most often, using 14 different tests. The traditional Western tests in the domains of attention (n = 8) and construction (n = 15), were unsuitable for low-educated patients. There was little variety in instruments measuring executive functioning (two tests, n = 13), and language (n = 12, of which 10 were naming tests). Many studies did not report a thorough adaptation procedure (n = 39) or blinding procedures (n = 29).

CONCLUSIONS

Various formats of memory tests seem suitable for low-educated, non-Western populations. Promising tasks in other cognitive domains are the Stick Design Test, Five Digit Test, and verbal fluency test. Further research is needed regarding cross-cultural instruments measuring executive functioning and language in low-educated people.

Naming and verbal learning in adults with Alzheimer's disease, mild cognitive impairment and in healthy aging, with low educational levels

Language assessment seems to be an effective tool to differentiate healthy and cognitively impaired aging groups. This article discusses the impact of educational level on a naming task, on a verbal learning with semantic cues task and on the MMSE in healthy aging adults at three educational levels (very low, low and high) as well as comparing two clinical groups of very low (0-3 years) and low education (4-7 years) patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) with healthy controls. The participants comprised 101 healthy controls, 17 patients with MCI and 19 with AD. Comparisons between the healthy groups showed an education effect on the MMSE, but not on naming and verbal learning. However, the clinical groups were differentiated in both the naming and verbal learning assessment. The results support the assumption that the verbal learning with semantic cues task is a valid tool to diagnose MCI and AD patients, with no influence from education.

Temporal unfolding of declining episodic memory on the Free and Cued Selective Reminding Test in the predementia phase of Alzheimer's disease: Implications for clinical trials

Introduction

Free and Cued Selective Reminding Test (FCSRT) performance identifies patients with preclinical disease at elevated risk for developing Alzheimer's dementia, predicting diagnosis better than other memory tests.

Methods

Based on literature mapping FCSRT performance to clinical outcomes and biological markers, and on longitudinal preclinical data from the Baltimore Longitudinal Study of Aging, we developed the Stages of Objective Memory Impairment (SOMI) model. Five sequential stages of episodic memory decline are defined by Free Recall (FR) and Total Recall (TR) score ranges and years prior to dementia diagnosis. We sought to replicate the SOMI model using longitudinal assessments of 142 Einstein Aging Study participants who developed AD over 10 years.

Results

Time to diagnosis was at least seven years if FR was intact, at least four years if TR was intact, and two years if TR was impaired, consistent with SOMI model predictions. The SOMI identified incipient dementia with excellent sensitivity and specificity.

Discussion

The SOMI model provides an efficient approach for clinical trial cognitive screening in advance of more costly biomarker studies and ultimately in clinical practice, and provides a vocabulary for understanding AD biomarker patterns and for re-analysis of existing clinical trial data.

Identifying memory impairment and early dementia in primary care

INTRODUCTION

This study examined the operating characteristics of two-stage case finding to identify memory impairment and very mild dementia.

METHODS

Primary care patients underwent two-stage testing and a subsequent diagnostic assessment to assess outcomes. Patients who screen positive for subjective cognitive decline on the Informant Questionnaire on Cognitive Decline in the Elderly undergo memory testing with the Free and Cued Selective Reminding Test with Immediate Recall. Outcomes were determined without access to these data. A split-half design with discovery and confirmatory samples was used.

RESULTS

One hundred seventeen of 563 (21%) patients had dementia and 68 (12%) had memory impairment but not dementia. Operating characteristics were similar in the discovery and confirmatory samples. In the pooled sample, combined, patients with memory impairment or dementia were identified with good sensitivity (72%) and high specificity (90%). Differences in ethnicity, educational level, or age (≤75, >75) did not affect classification accuracy.

DISCUSSION

Two-stage screening facilitates the efficient identification of older adults with memory impairment or dementia.

Two-stage screening for early dementia in primary care

OBJECTIVE

The objective was to compare two screening strategies for dementia in an urban primary care clinic, serving a low-education, minority community composed largely of Latino and African American patients.

METHOD

Two hundred and fifty-seven patients underwent two-stage patient-based screening (PBS) and informant-based screening (IBS) followed by a diagnostic evaluation. In the first stage, PBS included brief tests of episodic memory (Memory Impairment Screen), semantic memory (Animal Fluency), and executive function (Reciting Months Backwards). For IBS, the first stage consisted of the short Informant Questionnaire on Cognitive Decline in the Elderly, administered to a family member or friend. Patients who screened positive in the first stage of either strategy underwent testing with the picture version of the Free and Cued Selective Reminding Test with Immediate Recall to identify memory impairment. Sensitivity, specificity, and positive and negative predictive values were computed for various cutoffs of each test and combination of tests. Dementia was diagnosed using Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) criteria without access to the screening test results.

RESULTS

We identified 66 patients (25.7%) with previously undiagnosed dementia. Sensitivity was the same (77%) for both strategies but specificity was higher for IBS than for PBS (92% versus 83%). IBS's higher specificity makes it the preferred strategy if a knowledgeable informant is available.

CONCLUSION

Unrecognized dementia is common in primary care. Case-finding can be improved using either PBS or IBS two-stage screening strategies.

Construct and diagnostic validities of the Free and Cued Selective Reminding Test in the Alzheimer's disease spectrum

INTRODUCTION

The Free and Cued Selective Reminding Test (FCSRT) is a memory test that controls attention and acquisition, by providing category cues in the learning process. Because it enables an assessment of memory not confounded by normal age-related changes in cognition and a high accuracy on Alzheimer's disease (AD) evaluation, it has been suggested by the International Working Group on AD. Our aim was to assess the construct related validity of the FCSRT in the AD spectrum disorders.

METHOD

Patients were classified in two groups according to standard criteria: amnestic mild cognitive impairment (n = 100) and AD (n = 70). A matched control group (n = 101) of cognitively healthy subjects was included. The factorial structure of two models and respective construct and diagnostic validities were analyzed.

RESULTS

Both models revealed adequate fit values. The appropriated convergent validity and the lack of discriminant validity support the two factors as measuring the same construct (memory ability). The recalls of the FCSRT enabled high classification accuracy and diagnostic validity for both pathological groups.

CONCLUSIONS

This study represents a novel contribution regarding the adequacy of the FCSRT in terms of construct and diagnostic validities and shows the interest of including both immediate (learning) and delayed (retention) recalls. It gives also new possibilities regarding the use of the FCSRT in the memory assessment of AD spectrum disorders.

Conventional and robust norming in identifying preclinical dementia

OBJECTIVE

To contrast four approaches to norming two widely used memory tests in older adults for the purpose of detecting preclinical dementia.

METHOD

The study sample included participants from the Einstein Aging Study who were over age 70, were free of dementia at baseline, and were followed for at least 5 years. Norms were derived from a conventional sample (excluding individuals with dementia at baseline but not those who developed dementia during follow-up) and a robust normative sample (excluding persons with dementia at baseline as well as those who developed dementia over 5 years of follow-up). Both normative samples were examined with and without adjustment for age and education. We contrasted the picture version of the Free and Cued Selective Reminding Test with Immediate Recall (pFCSRT+IR) and the Logical Memory (LM) test for their ability to identify persons with preclinical dementia, operationally defined by the development of diagnosable dementia over 5 years of follow-up, using these four approaches to developing norms for detecting preclinical dementia.

RESULTS

Of 418 participants included in the conventional normative sample, the mean age was 78.2 years, and 59% were female. There were 78 incident cases of dementia over 5 years leaving 340 participants in the robust normative sample. Means and standard deviations were defined for both the conventional and robust normative samples, and cut-scores with and without adjustment were set at 1.5 standard deviations below the mean of each test. As predicted, in comparison with the conventional sample, the robust sample had higher cut-scores, which provided higher sensitivity for detecting preclinical dementia. This effect persisted regardless of adjustment. The pFCSRT+IR was more sensitive than LM in detecting incident dementia cases.

CONCLUSION

When using cognitive test norms to identify preclinical dementia, robust norming procedures improves detection using both the pFCSRT+IR and LM.