Evidence map›Paper›PMID 40779424›Full record

ArticleAlzheimer's & dementia : the journal of the Alzheimer's Association2025

Validity and reliability of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for dementia assessment in rural South Africa.

Muqi Guo, Tamara P Taporoski, Meagan T Farrell, Nomsa B Mahlalela, Brent Tipping, Adam M Brickman, Jennifer J Manly, Stephen Tollman, Lisa F Berkman, Darina T Bassil

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Article in Alzheimer's & dementia : the journal of the Alzheimer's Association, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

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2citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

10 authors.

Muqi GuoHarvard Center for Population and Development Studies, Harvard University, Cambridge, Massachusetts, USA.
Tamara P TaporoskiHarvard Center for Population and Development Studies, Harvard University, Cambridge, Massachusetts, USA.
Meagan T FarrellHarvard Center for Population and Development Studies, Harvard University, Cambridge, Massachusetts, USA.
Nomsa B MahlalelaHealth Economics and Epidemiology Research Office, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Brent TippingDepartment of Internal Medicine, Division of Geriatric Medicine, Wits Donald Gordon Medical Centre, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Adam M BrickmanTaub Institute for Research on Alzheimer's Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA.
Jennifer J ManlyTaub Institute for Research on Alzheimer's Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA.
Stephen TollmanMRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Agincourt, South Africa.
Lisa F BerkmanHarvard Center for Population and Development Studies, Harvard University, Cambridge, Massachusetts, USA.
Darina T BassilHarvard Center for Population and Development Studies, Harvard University, Cambridge, Massachusetts, USA.ORCID 0000-0002-2251-0613

Funding

SOCIAL AND ECONOMIC PREDICTORS OF PHYSICAL AND COGNITIVE FUNCTIONP01AG041710 · NIA · HARVARD UNIVERSITY D/B/A HARVARD SCHOOL OF PUBLIC HEALTH · PI Julia Katherine Rohr · 2013 to 2026
$37.3M
Cognitive Function, Alzheimer's Disease and Related Disorders in the HAALSI CohortR01AG054066 · NIA · HARVARD SCHOOL OF PUBLIC HEALTH · PI BERKMAN, LISA F · 2018 to 2022
$4.6M
NIA NIH HHS P01 AG041710NIA NIH HHS R01 AG054066
6 · The paper itself

Abstract

introductionThe Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) is suitable for screening dementia, particularly in populations with limited education. However, its feasibility and psychometrics in South Africa remain unassessed.

methodsWe analyzed 1309 index participant-informant dyads from the Health and Aging in Africa: Longitudinal Study of an International Network for the Demographic Evaluation of Populations and Their Health Community in South Africa study in rural South Africa, assessing IQCODE completeness, associations with index participant/informant characteristics, single-factor structure and reliability via factor analysis, and validity through correlations with neuropsychological tests.

resultsIndex participants averaged 71.9 years, with > 50% lacking formal education. IQCODE missingness declined across waves and was associated with index participant characteristics. IQCODE scores were correlated with both index participant and informant characteristics. The 16-item IQCODE demonstrated a single-factor structure explaining up to 66% of variance, strong internal consistency, and correlations with word and story recall, indicating high convergent validity. DISCUSSION: IQCODE is a reliable, valid dementia assessment tool in rural South Africa, supporting broader African applications and cross-national comparisons. HIGHLIGHTS: Sixteen-item Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) responses in rural South Africa support a single-factor construct, explaining up to 66% of total observed variance. The single-factor structure is reliable, as the IQCODE items data show high internal consistency (omega hierarchical = 0.90). The IQCODE score shows strong convergent validity with significant correlation with word and story recall memory measures. Index participants' characteristics are mainly associated with IQCODE completion. IQCODE contributes to dementia assessment in rural South Africa and other settings with low education populations.

Indexed as

Cognitive DysfunctionDementiaRural PopulationAgedAged, 80 and overFemaleHumansLongitudinal StudiesMaleMiddle AgedNeuropsychological TestsPsychometricsReproducibility of ResultsSouth AfricaSurveys and Questionnairesdementia assessmentfeasibilityInformant Questionnaire on Cognitive Decline in the Elderlyreliabilityrural regionSouth Africavalidity

Identifiers

PMID40779424
PMCPMC12333867

What Socratic holds

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LicenceCC BY-NC-ND
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.