Informant Questionnaire on Cognitive Decline in the Elderly – Self Report (IQCODE-SR)

Background / Development

The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) was developed by Anthony Jorm in 1988 as a standardized tool for assessing cognitive decline in older adults through informant observation.

The Self-Report version (IQCODE-SR) was later introduced to allow individuals to evaluate their own perceived cognitive changes, providing a complementary perspective to informant ratings.

Both forms are grounded in longitudinal assessment of functional cognitive performance, emphasizing real-world ability rather than test-based memory or attention scores.

Purpose / Intended Use

The IQCODE-SR is designed to detect subjective cognitive decline that may indicate early signs of mild cognitive impairment (MCI) or dementia.

It helps clinicians understand how individuals perceive changes in their cognitive function over time, particularly in memory, reasoning, and problem-solving.

The tool is commonly used in geriatric, neurological, and primary care assessments, as well as in research on aging and dementia prevention.

While it is not diagnostic, it serves as an effective screening and monitoring instrument.

Psychometric Properties

The IQCODE-SR demonstrates good reliability and validity across populations and languages:

• Internal consistency: α ≈ 0.95
• Test–retest reliability: r ≈ 0.90
• Construct validity: correlates with objective cognitive testing and clinical dementia diagnoses
• Discriminant validity: distinguishes between healthy aging, MCI, and dementia groups

Studies indicate that self-reported versions correlate moderately with informant reports, providing valuable complementary data.

Structure and Content

The IQCODE-SR contains 26 items (with shorter 16-item versions also available), each rated on a 5-point Likert scaleranging from Much better (1) to Much worse (5).

Items focus on changes in everyday cognitive performance over the past 10 years in areas such as:

• Remembering recent events and conversations
• Managing finances or appointments
• Learning new skills or using new technology
• Problem-solving and decision-making

The questionnaire is self-administered and typically completed in 5–10 minutes.

Scoring and Interpretation

Scores are averaged across all items to yield a mean score between 1.0 and 5.0.

• Higher scores indicate greater perceived decline.
• Cutoffs:
  • ≥3.3: Suggestive of possible cognitive impairment
  • <3.0: Generally consistent with stable cognitive functioning

Interpretation should incorporate corroborative data from informants, neuropsychological testing, and medical evaluation.

Clinical Application

The IQCODE-SR is most effective as part of a multi-source cognitive screening protocol.

It provides patient-centered insight into subjective cognitive concerns, supporting early detection, baseline documentation, and monitoring of change over time.

Clinicians may use it to guide referrals for neuropsychological testing or dementia evaluation.

In research, the IQCODE-SR is valuable for epidemiological studies and longitudinal tracking of cognitive aging.

References / Sources

Jorm, A. F. (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. https://doi.org/10.1017/S003329170002691X

Jorm, A. F. (1988). The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): A new method for assessing dementia based on informant reports. International Journal of Geriatric Psychiatry, 3(4), 215–226.