Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE)

The IQCODE (Informant Questionnaire for Cognitive Decline in the Elderly) is a commonly used International questionnaire that uses collateral information to assess for cognitive decline associated with functional impairment over a ten year span of time. The questionnaire can be filled out by a relative or friend who has known the elderly person for 10 years or more. The IQCODE for Neurocognitive Disorders "screening" or "triage" may have particular utility in primary care or general practice healthcare settings. This informant questionnaire can be very useful in the screening and evaluation of Neurocognitive Disorders, especially when combined with cognitive tests such as the Mini Mental State Examination (MMSE). It alone however isn’t sufficient to diagnose a Neurocognitive Disorder.

The shortened 16-question version of the IQCODE has also been well studied over multiple years, but it’s psychometric properties aren’t consistent from study to study. In general a cut-off point (average score) of 3.3 achieves a balance of sensitivity and specificity, however there are a limited number of studies of varying quality. A positive screening should be followed up with a detailed clinical evaluation to determine the diagnosis, severity, treatment course, and prognosis.