Informant Questionnaire on Cognitive Decline in the Elderly

BioPsychoSocial Assessment Tools for the Elderly - Assessment Summary Sheet

Test: Informant Questionnaire on Cognitive Decline in the Elderly

Year: 1989

Domain: Psychological

Assessment Tool Category: Dementia/Alzheimer's

Variations/Translations: There is an abbreviated short version of this test containing 16 items as opposed to 26. Translations include Italian and Spanish, including an abbreviated version. There is also a Dutch, Canadian French, Chinese, and Thai version.

Setting: Clinical

Method of Delivery: Self-administered questionnaire

Description: This test originated as an interview where the informant was asked to rate the subject’s improvement or decline in 26 aspects of memory and intelligence over a ten year period. This questionnaire was derived from that interview schedule. This self-administered questionnaire containing 26 items covers changes in learning, recall abilities, recognition, comprehension, and other aspects of intelligence.

Scoring/Interpretation: Each item is rated on a one to five scale. One represents considerable improvement, 3 indicates no change, and five represents considerable deterioration. An overall change score is calculated by averaging the scores on each item, so that the overall score can be interpreted on the same scale as each item. Scores below three indicate improvement and three indicates no change. Scores from 3.01 to 3.5 indicate slight decline; 3.51 to 4 indicate moderate decline; and 4.01 and higher indicate severe decline. Because this test is used as a screening test for dementia, different studies have proposed different cutting-points. For patients without dementia, scores higher than 3.3 predicted the subsequent development of dementia.

Time to Administer: N/A

Availability: Available in source article (Jorm & Jacomb, 1989) and in McDowell (2006).

Software: N/A

Website: N/A

Quantitative/Qualitative: Quantitative

Validity (Quantitative): Factorial validity: Jorm & Jacomb reported a factor analysis where all items loaded highly on the first factor, ranging from 0.47 to 0.81 in different samples. Criterion validity: every item distinguishes significantly and this test correctly identifies 92.7% of those with dementia, with a specificity of 88%. Concurrent validity: When compared to the MMSE, the highest correlations include -0.74, -0.75, -0.78 and lower values include -0.44, and -0.41.

Reliability (Quantitative): All items have high item-total correlations. In a sample of Alzheimer’s patient’s chronbach’s alpha was 0.93. Values of 0.95 have been reported for a general population sample (N=613). In a one year follow up of 260 people with dementia, the IQCODE showed a significant decline in scores, giving a retest correlation of 0.75.

References:

McDowell, I. (2006). Measuring Health: A guide to rating scales and questionnaires 3rd Ed. New York: Oxford University Press.

Jorm, A.F., Jacomb, P.A. (1989). The informant questionnaire on cognitive decline in the elderly (IQCODE): socio-demographic correlates, reliability, validity and some norms. Psychological Medicine, 19, 1015-1022.

Comments: N/A