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    Cognition · 16 items · 1.00–5.00 · Jorm AF (1994). A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation. Psychological Medicine, 24(1), 145–153.

    Short IQCODE: Scoring, Cutoffs & Interpretation

    A 16-item informant questionnaire rating an older person's cognitive change over the past 10 years, used to screen for possible dementia.

    IQCODE0 / 16

    Think of how your friend or relative was 10 years ago, and compare it with how they are now. For each situation, indicate whether their performance has improved, stayed the same or got worse over those 10 years.

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    01Compared with 10 years ago, how is this person at: remembering things about family and friends e.g. occupations, birthdays, addresses
    02Compared with 10 years ago, how is this person at: remembering things that have happened recently
    03Compared with 10 years ago, how is this person at: recalling conversations a few days later
    04Compared with 10 years ago, how is this person at: remembering his/her address and telephone number
    05Compared with 10 years ago, how is this person at: remembering what day and month it is
    06Compared with 10 years ago, how is this person at: remembering where things are usually kept
    07Compared with 10 years ago, how is this person at: remembering where to find things which have been put in a different place from usual
    08Compared with 10 years ago, how is this person at: knowing how to work familiar machines around the house
    09Compared with 10 years ago, how is this person at: learning to use a new gadget or machine around the house
    10Compared with 10 years ago, how is this person at: learning new things in general
    11Compared with 10 years ago, how is this person at: following a story in a book or on TV
    12Compared with 10 years ago, how is this person at: making decisions on everyday matters
    13Compared with 10 years ago, how is this person at: handling money for shopping
    14Compared with 10 years ago, how is this person at: handling financial matters e.g. the pension, dealing with the bank
    15Compared with 10 years ago, how is this person at: handling other everyday arithmetic problems e.g. knowing how much food to buy, knowing how long between visits from family or friends
    16Compared with 10 years ago, how is this person at: using his/her intelligence to understand what's going on and to reason things through
    0 of 160.00 / 5.00

    02 - The clinician's brief

    Last reviewed: · Reviewed by Lotte Kjær Svalberg

    01 - What it measures

    What this scale measures.

    The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) measures change in a person's everyday cognitive performance over the previous ten years, as judged by someone who knows them well. The short form in use here asks an informant - usually a spouse, adult child or close friend - to rate 16 everyday situations, from remembering recent conversations to handling money and learning to use new gadgets, on a five-point scale from "much improved" to "much worse". A rating of 3 means no change.

    Because every item is anchored to the person's own earlier performance, the IQCODE measures decline from an individual baseline rather than current ability against a population norm. This is its defining property: a person with limited schooling and a university professor are both compared with their former selves, which makes the instrument far less confounded by education and premorbid ability than performance tests such as the MMSE. It captures cognition as it operates in daily life, and it can be completed when the patient themselves cannot be tested - in acute illness, when direct testing would be unreliable, or remotely.

    02 - Origin & purpose

    Where it comes from.

    The IQCODE was developed by Anthony Jorm and Patricia Jacomb at the Australian National University, published in 1989 as a 26-item informant questionnaire 1. In the validation sample of 613 general-population informants it showed very high internal consistency (alpha 0.95) and, in 309 informants of dementing patients re-tested after a year, test-retest reliability of r 0.75. It was designed from the outset to assess decline independently of premorbid ability, addressing the long-standing complaint that brief cognitive tests penalise people with little education and flatter those with a lot.

    In 1994 Jorm published the 16-item short form, derived from item analyses across four datasets and cross-validated against clinical dementia diagnosis 2. The short form correlates 0.98 with the full 26-item version and performs just as well against diagnosis, so it has become the recommended default in both research and clinical use. The IQCODE has since been translated into many languages and is one of the most widely studied informant instruments in dementia screening, with a dedicated suite of Cochrane diagnostic accuracy reviews 56.

    03 - Scoring & cutoffs

    How scoring works.

    The 16 ratings are averaged, giving a score from 1 to 5. A mean of 3.0 means the informant reports no change over ten years; above 3 indicates decline, below 3 improvement. Unlike sum-scored questionnaires, missing items are handled naturally, because the score is a mean of the items completed. Screening cutoffs in the literature range from about 3.3 to 3.6: lower cutoffs favour sensitivity (fewer missed cases), higher cutoffs favour specificity (fewer false alarms). A cutoff of 3.44 is a widely used clinical compromise - in Harwood and colleagues' 1997 validation it identified every case of dementia (sensitivity 100%) while correctly reassuring 86% of those without 3. The Cochrane reviews note that studies rarely use identical cutoffs, so the threshold should be chosen for the setting, and the score should always prompt fuller assessment rather than act as a diagnosis 5.

    Score
    Severity
    Interpretation
    1.00–2.99
    Improvement or no decline reported
    The informant reports the person is the same as or better than 10 years ago. No screening concern from this instrument.
    3.00–3.00
    No change compared with 10 years ago
    An average of exactly 3.00 means the informant reports no overall change over the past 10 years.
    3.01–3.43
    Some decline reported, below the usual screening threshold
    Some decline is reported but the average falls below the usual screening threshold. Consider repeating over time and correlating with cognitive testing.
    3.44–5.00
    Positive screen - further assessment warranted
    Cognitive decline at a level where further assessment for dementia is warranted. Common cutoffs range 3.3-3.6; 3.44 is the widely used clinical threshold.

    The Short IQCODE is completed by an informant - a relative, friend or carer who has known the person well for at least 10 years - and not by the patient. It is a screening aid only and does not diagnose dementia; interpret it alongside clinical assessment, cognitive testing and history.

    04 - Validation evidence

    How well it performs.

    The Short IQCODE was cross-validated at development: Jorm's 1994 analysis showed the 16-item form correlating 0.98 with the parent instrument and discriminating dementia as well as the full version 2. Internal consistency is consistently excellent - Jorm's 2004 review reports Cronbach's alpha between 0.93 and 0.97 across studies 4. In a meta-analysis of seven studies, the IQCODE separated dementia cases from non-cases with a weighted effect size of 1.75, slightly larger than the MMSE's 1.48 in the same analysis 4.

    The most rigorous accuracy synthesis is the 2021 Cochrane review of secondary-care studies: pooled sensitivity 0.90 (95% CI 0.83-0.94) and specificity 0.54 (95% CI 0.44-0.64) for dementia in hospital settings 5. The high sensitivity supports its use for case-finding; the modest specificity in hospital populations means positive results over-call and must be followed by clinical assessment. Crucially for its intended purpose, IQCODE scores correlate only minimally with the patient's education and premorbid ability - the confounders that most trouble performance-based screens.

    0.98
    Correlation with 26-item IQCODE

    Short 16-item form vs the original (Jorm 1994)

    alpha 0.93-0.97
    Internal consistency

    Across studies (Jorm 2004 review)

    100% / 86%
    Sensitivity / specificity at 3.44

    Medical inpatients (Harwood et al. 1997)

    0.90 / 0.54
    Pooled sensitivity / specificity

    Dementia in secondary care (Cochrane 2021)

    05 - How it compares

    How it compares to the alternatives.

    Instrument
    Items
    Time
    When to reach for it
    IQCODE
    16, informant-rated
    ~5 min
    You need baseline-relative change, the patient cannot be tested, or education/language make performance tests unfair
    30 points
    7-10 min
    You need the historically standard bedside performance test; note it is licensed and education-sensitive
    3-word recall + clock draw
    ~3 min
    You need the fastest possible performance screen in primary care or pre-op settings
    8, informant-rated
    ~3 min
    You want an ultra-brief informant screen; the IQCODE gives a finer-grained picture when there is time
    10
    7-10 min
    You want a free MMSE alternative with better sensitivity for mild neurocognitive disorder

    06 - When to use it

    Right tool, wrong tool.

    The IQCODE is a screening aid for suspected dementia where an informant's perspective on decline is available and valuable. It complements, rather than replaces, direct cognitive testing and full clinical assessment.

    Reach for it when

    • -A reliable informant who has known the patient for years is available
    • -You need decline from the person's own baseline, not a norm-referenced snapshot
    • -The patient cannot complete testing (acute illness, sensory impairment, distress)
    • -Education, language or literacy would bias a performance test
    • -Remote or telephone assessment, or triage before a memory-clinic referral
    • -Pairing with a performance test - informant report plus direct testing outperforms either alone

    Reach for something else when

    • -No informant, or the informant has infrequent contact with the patient
    • -Detecting mild cognitive impairment - the evidence base is for dementia, not MCI
    • -Differentiating dementia subtypes - it grades decline, not aetiology
    • -Tracking short-term change or treatment response
    • -As a diagnostic instrument - a positive screen always needs full assessment

    07 - Confidence & precision

    Reading the score with care.

    No standard error of measurement or minimal clinically important difference has been established for the IQCODE, and its score depends on the informant as much as the patient, so small differences around the cutoff should carry little weight. The sensible reading is categorical: clearly below ~3.3 is reassuring, clearly above ~3.6 warrants assessment, and the zone between is where informant quality, clinical context and a paired performance test should decide. Repeat measurement with a different informant is not comparable measurement.

    08 - Limitations

    What it cannot tell you.

    The IQCODE inherits the biases of its informant: ratings are influenced by the informant's own mood (depression and anxiety inflate reported decline), by the quality of the relationship, and by how much contact they have with the patient. Specificity is modest in hospital settings (0.54 pooled), so it over-identifies in acutely unwell populations 5. The ten-year window is awkward when the informant has known the patient for less than a decade. Evidence for detecting MCI, as opposed to dementia, is limited. And like every screen on this site, it does not diagnose: it selects people for proper assessment.

    Common questions from clinicians

    FAQ

    References

    Source literature.

    1. [1]Jorm AF, Jacomb PA. The IQCODE: socio-demographic correlates, reliability, validity and some norms. Psychological Medicine 19(4):1015-1022. (1989)
    2. [2]Jorm AF. A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): development and cross-validation. Psychological Medicine 24(1):145-153. (1994)
    3. [3]Harwood DMJ, Hope T, Jacoby R. Cognitive impairment in medical inpatients: screening for dementia - is history better than mental state? Age and Ageing 26(1):31-35. (1997)
    4. [4]Jorm AF. The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): a review. International Psychogeriatrics 16(3):275-293. (2004)
    5. [5]Burton JK, Fearon P, Noel-Storr AH, et al. IQCODE for the detection of dementia within a secondary care setting. Cochrane Database of Systematic Reviews. (2021)
    6. [6]Burton JK, Stott DJ, McShane R, et al. IQCODE for the early detection of dementia across a variety of healthcare settings. Cochrane Database of Systematic Reviews. (2021)

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