The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) is a

questionnaire A questionnaire is a research instrument that consists of a set of questions (or other types of prompts) for the purpose of gathering information from respondents through survey or statistical study. A research questionnaire is typically a mix of ...

that can be filled out by a relative or other supporter of an older person to determine whether that person has declined in

cognitive function Cognitive skills, also called cognitive functions, cognitive abilities or cognitive capacities, are brain-based skills which are needed in acquisition of knowledge, manipulation of information and reasoning. They have more to do with the mechanisms ...

ing. The IQCODE is used as a screening test for

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

. If the person is found to have significant cognitive decline, then this needs to be followed up with a medical examination to determine whether dementia is present.

Rationale behind the IQCODE

Most screening tests for dementia involve a brief list of questions to directly assess cognitive functioning. Probably the best-known dementia screening test of this kind is the Mini-Mental State Examination. A disadvantage of such tests is that they are affected by the person's level of

education Education is a purposeful activity directed at achieving certain aims, such as transmitting knowledge or fostering skills and character traits. These aims may include the development of understanding, rationality, kindness, and honesty ...

, familiarity with the dominant

language Language is a structured system of communication. The structure of a language is its grammar and the free components are its vocabulary. Languages are the primary means by which humans communicate, and may be conveyed through a variety of ...

and culture in their country, and level of intelligence before the onset of dementia. Because of this, cognitive screening tests can falsely indicate dementia in people with lower education, culturally and linguistically diverse backgrounds, and lower intelligence. Cognitive screening tests may also have the opposite problem, falsely indicating that a person does not have dementia, especially if that person had a higher level of education or intelligence originally. The IQCODE attempts to overcome this problem by assessing change from earlier in life, rather than the person's current level of functioning. It does this by making use of the informant's knowledge of both the person's earlier and current cognitive functioning.

Content

The IQCODE lists 26 everyday situations where a person has to use their

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered ...

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can be des ...

. Examples of such situations include: “Remembering where to find things which have been put in a different place from usual” and “Handling money for shopping”. Each situation is rated by the informant for amount of change over the previous 10 years, using the following scale: 1. Much improved, 2. A bit improved, 3. Not much change, 4. A bit worse, 5. Much worse.

Scoring

The IQCODE is generally scored by averaging the ratings across the 26 situations. A person who has no cognitive decline will have an average score of 3, while scores of greater than 3 indicate that some decline has occurred. However, some users of the IQCODE have scored it by summing the scores to give a range from 26 to 130.Jorm, A.F. (2004). The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): A review. International Psychogeriatrics, 16, 1-19.
/ref> Various cutoff scores have been used to distinguish dementia from normality. In community samples, cutoff scores for likely dementia have ranged from 3.3 and above to 3.6 and above, while in patient samples the cutoff scores have ranged from 3.4 and above to 4.0 and above. To improve the detection of dementia, the IQCODE can be used in combination with the Mini-Mental State Examination. A graphical method of combining the two tests has been developed and is known as the Demegraph.

Validity of the IQCODE

The IQCODE has been found to distinguish people who have or do not have dementia. A low score on the IQCODE in a person who does not currently have dementia has also been found to predict that they will develop dementia in the future. The IQCODE has found to correlate highly with conventional dementia screening tests, such as the Mini-Mental State Examination, and to have moderate correlations with a range of neuropsychological tests. It has also been found to correlate with change in cognitive test scores over time. The IQCODE has near-zero

correlations In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistics ...

with a person's level of education or with their intelligence earlier in life. This is in contrast to conventional dementia screening tests like the Mini-Mental State Examination, which are affected by education and intelligence as well as the presence of dementia.

Other versions of the IQCODE

The original IQCODE has 26 items. A Short IQCODE has been developed, consisting of the 16 items, and has been found to be as valid as the full version.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, 145-153.
/ref> Because it is briefer and of equal validity, the Short IQCODE can generally be used in preference to the original version. Because the IQCODE does not require the involvement of the person being assessed, it can be used to assess probable dementia in someone who is unable to be assessed because they have had a stroke, developed delirium or have died. A Retrospective IQCODE has been developed for this purpose. The IQCODE has been translated into many languages, including Chinese, Danish, Dutch, Finnish, French, Canadian French, German, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Spanish and Thai.

References

External links

IQCODE

Demegraph
{{DEFAULTSORT:Informant Questionnaire On Cognitive Decline In The Elderly Cognitive impairment and dementia screening and assessment tools Cognitive tests Geriatrics