What is the IQCODE-26 and what does it measure?

The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE-26) is a 26-item questionnaire completed by a carer or close informant. It measures perceived cognitive and functional change in an older adult compared to their status 10 years previously.

How is the IQCODE-26 scored?

Each of the 26 items is rated 1–5 (1 = much improved to 5 = much worse). The mean score (sum/26) ranges from 1.0 to 5.0. A mean above 3 indicates overall decline from baseline.

What is the IQCODE cutoff for dementia?

The most commonly cited screening cutoff is 3.38, with sensitivity approximately 83% and specificity approximately 89% for dementia in clinical populations. Higher cutoffs (3.5–3.6) increase specificity at the cost of sensitivity.

Who developed the IQCODE?

IQCODE was developed by Anthony F. Jorm and colleagues at the Australian National University. The original 26-item version was published in 1989 in Psychological Medicine.

Why is IQCODE less education-biased than the MMSE?

IQCODE measures change from an individual's personal baseline rather than comparing performance to population norms. A patient with limited education who performs at their lifelong level will not score worse than a highly educated patient who has declined.

Is there a shorter version of the IQCODE?

Yes. The IQCODE-16 (16-item short form) correlates highly with the 26-item version and has similar diagnostic accuracy. It takes approximately half the time to administer and is commonly used in clinical practice.

What types of cognitive and functional activities does IQCODE-26 assess?

IQCODE-26 includes items on memory for recent events, conversations, and faces; learning new information; orientation to time, place, and person; managing finances, medications, and daily tasks; and use of household appliances and telephone.

Can IQCODE-26 be used alongside cognitive performance tests?

Yes. IQCODE-26 and cognitive performance tests (MMSE, MoCA) complement each other — IQCODE provides longitudinal change perspective while performance tests provide current status. Using both improves diagnostic accuracy for dementia.

How long does IQCODE-26 take to administer?

IQCODE-26 typically takes 10–15 minutes to complete. It can be administered in person or mailed to a carer before the clinic appointment, allowing completion in advance and saving consultation time.

Is IQCODE appropriate for use in different cultural settings?

Yes. Because IQCODE measures change from an individual's own baseline rather than comparing to population norms, it is less culturally biased than standardised performance tests. Validated translations in over 20 languages further extend its cross-cultural applicability.

What limitations does IQCODE-26 have?

Key limitations include dependence on informant availability and reliability, potential bias from caregiver stress or under-reporting of decline, limited ability to distinguish dementia subtypes, and requirement for 10 years of close contact.

Can IQCODE-26 detect mild cognitive impairment (MCI)?

IQCODE has moderate sensitivity for MCI; it performs better for frank dementia. Scores between 3.2 and 3.5 may reflect MCI or subjective cognitive decline and should prompt neuropsychological evaluation. Combining with direct cognitive testing improves MCI detection.

Online Medical Tools — IQCODE-26

Printed on 9/4/2026

For informational purposes only. This is not medical advice.

Geriatrics

IQCODE-26

IQCODE-26 is an informant questionnaire that evaluates perceived cognitive change over time in an older adult. The mean item score reflects degree of decline, with higher scores indicating greater concern.

Formula: IQCODE-26 score = mean of 26 item ratings, range 1.0-5.0.

IQCODE-26 mean score

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How It Works

Identify a Reliable Informant

Select an informant who has had close, regular contact with the patient for at least 10 years and can compare current cognitive function to how the patient was 10 years ago. Family members, long-term carers, or close friends who see the patient daily or weekly are ideal informants.

Rate 26 Cognitive and Functional Activities

The informant rates each of 26 cognitive and functional activities on a 5-point scale comparing current performance to 10 years ago: 1 = much improved, 2 = a bit improved, 3 = not much change, 4 = a bit worse, 5 = much worse. Activities include memory for recent events and conversations, orientation, use of money, managing daily tasks, and social interactions.

Calculate Mean Score and Apply Threshold

Sum all 26 item ratings and divide by 26 to obtain the mean score (range 1.0–5.0). A mean of 3 is neutral. Scores above 3 indicate perceived decline; the commonly used diagnostic cutoff is approximately 3.38 (sensitivity ~83%, specificity ~89%), though thresholds vary by setting and population.

Who Uses the IQCODE-26

Dementia Screening in Primary Care

General practitioners and primary care nurses

IQCODE-26 provides a low-education-bias informant perspective that complements brief cognitive tests in primary care, particularly useful in older patients where educational level may confound performance-based scores.

Pre-operative Cognitive Risk Assessment

Anaesthesiologists and surgical teams

Identifying pre-existing cognitive decline before major surgery through an informant-based tool helps predict post-operative delirium risk and informs peri-operative monitoring requirements.

Memory Clinic Initial Workup

Neuropsychologists and memory clinic teams

IQCODE-26 provides collateral cognitive history in memory clinic assessments, offering longitudinal change data that standardised cross-sectional cognitive tests cannot capture.

Hospital Admission Cognitive Baseline

Geriatricians and hospital medical teams

Collecting IQCODE-26 data at admission from accompanying family members establishes a cognitive baseline, helping distinguish acute confusion (delirium) from chronic impairment (dementia).

Community Dementia Surveillance

Public health researchers and epidemiologists

IQCODE-26 has been used in large-scale epidemiological studies of dementia prevalence due to its language-adaptable, informant-based format that avoids cultural and educational biases of direct cognitive tests.

Pro Tips

Informant Quality Matters More Than Tool Selection

The reliability of IQCODE-26 depends entirely on the informant's knowledge of the patient over time. Verify that the informant has had close, consistent contact for at least 10 years and can meaningfully compare current to past function.

IQCODE Is Less Education-Biased Than MMSE

Unlike the MMSE or MoCA, which penalise patients with low educational attainment, IQCODE-26 asks about change from a personal baseline. This makes it particularly valuable for assessing patients with low literacy, limited education, or non-English language backgrounds.

Anchor the Rating to 10 Years Ago Specifically

The standard comparison anchor is 10 years prior. If the patient has only been known to the informant for fewer years, adjust the comparison period and document this, as using a different reference period affects score interpretation.

Score 3 Is the Midpoint — Not Normal in Older Adults

A mean score of 3.0 technically means 'no change,' but even marginal scores above 3.0 in octogenarians carry clinical significance. Do not dismiss scores of 3.2–3.4 as normal — these represent early decline signals worth pursuing.

Combine With Direct Cognitive Testing

IQCODE-26 and MMSE/MoCA/RUDAS assess different dimensions. Concordance between a high IQCODE mean and low cognitive test performance strongly supports dementia diagnosis. Discordance (high IQCODE but normal test) may indicate rater bias or anxiety.

Ask About Specific Scenarios, Not Generalities

When administering IQCODE-26, prompt the informant with concrete examples for each item rather than abstract global assessments to improve accuracy.

Use the 16-Item Short Form for Rapid Screening

The IQCODE-16 (short form) correlates closely with the 26-item version and takes approximately half the time to administer. Consider the short form for high-volume screening settings where time is limited.

Document Informant Relationship and Contact Frequency

Record who completed the IQCODE, their relationship to the patient, and how often they interact. A daily carer will have more accurate observations than an estranged relative who sees the patient monthly.

Common Questions About Your Results

Evidence-Based Methodology

IQCODE long forms have longstanding validation for dementia screening support across diverse settings.

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: Dementia Informant Screening Review 2026.04
Source set version:: IQCODE-26 source set v1

How to Interpret Your Result

Higher IQCODE-26 means indicate greater informant-reported cognitive decline and support further evaluation.

When to Use This Tool

Use when a reliable informant is available and longitudinal cognitive-change perspective is needed.

Limitations

Results depend on informant accuracy, patient-contact frequency, and contextual bias.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Sources

Changelog

April 21, 2026 · v1.0.0
Added IQCODE-26 trust metadata and initial changelog for evidence-version tracking.

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