Evidence map›Paper›PMID 36781176›Full record

ArticlePsychogeriatrics : the official journal of the Japanese Psychogeriatric Society2023

Establishing conversion of the 16-item Informant Questionnaire on Cognitive Decline in the Elderly scores into interval-level data across multiple samples using Rasch methodology.

Quoc Cuong Truong, Katya Numbers, Carol C Choo, Adam C Bentvelzen, Vibeke S Catts, Matti Cervin, Anthony F Jorm, Nicole A Kochan, Henry Brodaty, Perminder S Sachdev and 1 more

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Article in Psychogeriatrics : the official journal of the Japanese Psychogeriatric Society, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
0.4field-weighted citation impact, top 39% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed, 2 citations in OpenAlex.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors at 5 institutions in 4 countries.

Quoc Cuong TruongSchool of Psychology, University of Waikato, Hamilton, New Zealand.ORCID https://orcid.org/0000-0002-3876-129X
Katya NumbersCentre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, New South Wales, Australia.
Carol C ChooCollege of Healthcare Sciences, James Cook University, Townsville, Queensland, Australia.
Adam C BentvelzenCentre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, New South Wales, Australia.
Vibeke S CattsCentre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, New South Wales, Australia.
Matti CervinDepartment of Clinical Sciences Lund, Child and Adolescent Psychiatry, Faculty of Medicine, Lund University, Lund, Sweden.
Anthony F JormCentre for Mental Health, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia.
Nicole A KochanCentre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, New South Wales, Australia.
Henry BrodatyCentre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, New South Wales, Australia.
Perminder S SachdevCentre for Healthy Brain Ageing (CHeBA), University of New South Wales, Sydney, New South Wales, Australia.
Oleg N MedvedevSchool of Psychology, University of Waikato, Hamilton, New Zealand.
UNSW Sydney · AUUniversity of Waikato · NZJames Cook University · AULund University · SEThe University of Melbourne · AU

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe 16-item Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE-16) is a well-validated and widely-used measure of cognitive changes (CCs) among older adults. This study aimed to use Rasch methodology to establish psychometric properties of the IQCODE-16 and validate the existing ordinal-to-interval transformation algorithms across multiple large samples.

methodsA Partial Credit Rasch model was employed to examine psychometric properties of the IQCODE-16 using data (n = 918) from two longitudinal studies of participants aged 57-99 years: the Older Australian Twins Study (n = 450) and the Canberra Longitudinal Study (n = 468), and reusing the Sydney Memory and Ageing Study (MAS) sample (n = 400).

resultsInitial analyses indicated good reliability for the IQCODE-16 (Person Separation Index range: 0.82-0.90). However, local dependency was identified between items, with several items showing misfit to the model. Replicating the existing Rasch solution could not reproduce the best Rasch model fit for all samples. Combining locally dependent items into three testlets resolved all misfit and local dependency issues and resulted in the best Rasch model fit for all samples with evidence of unidimensionality, strong reliability, and invariance across person factors. Accordingly, new ordinal-to-interval transformation algorithms were produced to convert the IQCODE-16 ordinal scores into interval data to improve the accuracy of its scores.

conclusionsThe findings of this study support the reliability and validity of the IQCODE-16 in measuring CCs among older adults. New ordinal-to-interval conversion tables generated using samples from multiple independent datasets are more generalizable and can be used to enhance the precision of the IQCODE-16 without changing its original format. An easy-to-use converter has been made available for clinical and research use.

Indexed as

Cognitive DysfunctionAgedAustraliaHumansLongitudinal StudiesPsychometricsReproducibility of ResultsSurveys and Questionnairescognitive changesInformant Questionnaire on Cognitive Decline in the ElderlymeasurementRasch analysisreliability

Identifiers

PMID36781176
PMCPMC11578006
OpenAlexW4320481077

What OpenQuestion 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 OpenQuestion graph.