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A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation
Jorm AF.. Psychological medicine, 1994-02-01
Topic: Risk, prevention and care in population studies
Data from four studies were used to assess the psychometric properties of the 26 IQCODE items. The items were assessed in terms of item-total correlations, test-retest reliabilities, correlations with indicators of current cognitive functioning and correlations with indicators of premorbid cognitive functioning. These data were used to develop a 16-item short form. The short form was cross-validated in a new sample using dementia/delirium diagnosis as the validity standard. It was found to perform as well as the long form.
Key findings
- Data from four studies were used to assess the psychometric properties of the 26 IQCODE items.
- The items were assessed in terms of item-total correlations, test-retest reliabilities, correlations with indicators of current cognitive functioning and correlations with indicators of premorbid cognitive functioning.
- These data were used to develop a 16-item short form.
- The short form was cross-validated in a new sample using dementia/delirium diagnosis as the validity standard.
- It was found to perform as well as the long form.
Why it matters
This 1994 study cut the 26-question IQCODE, a questionnaire about an older person's cognitive decline that is answered by someone who knows them well, down to 16 questions, using data from four earlier studies. Checked against dementia or delirium diagnoses in a new group of people, the 16-question version "was found to perform as well as the long form." It is a screening questionnaire, not a diagnosis, and the summary gives no accuracy figures or cut-off scores.
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Study details
- Evidence strengthLow
How this study scored 49/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Psychological medicine) |
| Journal's citation record | 3 / 4 | Psychological Medicine: journal h-index 331 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| 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 | 1994 — 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 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 7 / 7 | Cited 1,209 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 35.6 citations a year over 34 year(s) since 1994 |
| Impact for its field and year | 2 / 6 | Cited 2.3× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 4 / 6 | Cited by 58 other studies in this library |
| Still being cited | 3 / 4 | Cited 156 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Anthony Francis Jorm: h-index 137 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Australian National University: institution h-index 1,088 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 8208879) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 49 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
May need a subscription OpenAlex found no free copy of the full text (checked 6 Feb 1020), so the publisher may charge for it. The PubMed abstract is free.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Jorm, A. F. (1994). A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation. Psychological medicine. https://doi.org/10.1017/s003329170002691x
Vancouver
Jorm AF. A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation. Psychological medicine. 1994. doi:10.1017/s003329170002691x. PMID: 8208879.
BibTeX
@article{jorm1994-8208879,
author = {Jorm, A. F.},
title = {{A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation}},
journal = {Psychological medicine},
year = {1994},
doi = {10.1017/s003329170002691x},
pmid = {8208879},
url = {https://doi.org/10.1017/s003329170002691x}
}
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Referenced by this study and also in the alzhub library, so you can read them here.
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