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The Informant Questionnaire on cognitive decline in the elderly (IQCODE): a review
Jorm AF.. International psychogeriatrics, 2004-09-01
Topic: Health services, long-term care and technology
Background and aims The IQCODE is widely used as a screening test for dementia, particularly where the subject is unable to undergo direct cognitive testing or for screening in populations with low levels of education and literacy. This review draws together research on the psychometric properties and validity of the IQCODE. Method A systematic search of the literature was carried out using three databases. Results The review shows that the questionnaire has high reliability and measures a single general factor of cognitive decline. It validly reflects past cognitive decline, performs at least as well at screening as conventional cognitive screening tests, predicts incident dementia, and correlates with a wide range of cognitive tests. A particular strength is that the IQCODE is relatively unaffected by education and pre-morbid ability or by proficiency in the culture's dominant language. The disadvantage of the IQCODE is that it is affected by informant characteristics such as depression and anxiety in the informant and the quality of the relationship between the informant and the subject. Conclusions Because the IQCODE provides information complementary to brief cognitive tests, harnessing them together can improve screening accuracy.
Key findings
- Results The review shows that the questionnaire has high reliability and measures a single general factor of cognitive decline.
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Study details
- Evidence strengthLow
How this study scored 57/100
Published in a peer-reviewed journal, and it is a meta-analysis pooling many studies. Scored zero for sample size, effect reported and studied in people because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multi-centre collaboration, so those were left out: it earned 33 of the 58 points we could judge it on, which is 57 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (International psychogeriatrics) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 12 / 12 | A meta-analysis pooling many studies (from PubMed type “Meta-Analysis”) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2004 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 15559753) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 33 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 33 of the 58 points we could judge it on is 57 out of 100. |
| Total | 57 / 100 | — |
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APA 7th
Jorm, A. F. (2004). The Informant Questionnaire on cognitive decline in the elderly (IQCODE): a review. International psychogeriatrics. https://doi.org/10.1017/s1041610204000390
Vancouver
Jorm AF. The Informant Questionnaire on cognitive decline in the elderly (IQCODE): a review. International psychogeriatrics. 2004. doi:10.1017/s1041610204000390. PMID: 15559753.
BibTeX
@article{jorm2004-15559753,
author = {Jorm, A. F.},
title = {{The Informant Questionnaire on cognitive decline in the elderly (IQCODE): a review}},
journal = {International psychogeriatrics},
year = {2004},
doi = {10.1017/s1041610204000390},
pmid = {15559753},
url = {https://doi.org/10.1017/s1041610204000390}
}