The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): socio-demographic correlates, reliability, validity and some norms

Psychological MedicinePublished 1 November 1989

Anthony F. Jorm, P. A. Jacomb

DOI10.1017/s0033291700005742

Source URL

Citations1,124

SJR quartileQ1

SJR score2.42

SNIP1.85

TL;DR

The questionnaire was found to have high internal reliability in the general population sample and reasonably high test-retest reliability over one year in the dementing sample, and the total IQCODE score, as well as each of the 26-items, was finding to discriminate well between the generalpopulation and dementing samples.

Abstract

The IQCODE is a questionnaire which asks an informant about changes in an elderly person's everyday cognitive function. The questionnaire aims to assess cognitive decline independent of pre-morbid ability. In the present study, the IQCODE was administered to a sample of 613 informants from the general population. In addition, the questionnaire was administered to informants of 309 dementing subjects who had filled it out one year previously. A principal components analysis, using the general population sample, confirmed that the IQCODE measures a general factor of cognitive decline. The questionnaire was found to have high internal reliability in the general population sample (alpha = 0.95) and reasonably high test-retest reliability over one year in the dementing sample (r = 0.75). The total IQCODE score, as well as each of the 26-items, was found to discriminate well between the general population and dementing samples. The correlation with education was quite small (r = -0.13), indicating that contamination by premorbid ability is not a problem.

Keywords

Medicine

Journal of Psychiatric Research“Mini-mental state”

86,858 Citations1975Marshal F. Folstein, Susan E. Folstein +1 more

A simplified, scored form of the cognitive mental status examination, the “Mini-Mental State” (MMS) which includes eleven questions, requires only 5-10 min to administer, and is therefore practical to use serially and routinely.

The British Journal of PsychiatryThe Association Between Quantitative Measures of Dementia and of Senile Change in the Cerebral Grey Matter of Elderly Subjects

4,123 Citations1968G. Blessed, B. E. Tomlinson +1 more

The expectation of mental disorder shows a steep increase with advancing chronological age, and beyond 75 years a large part of this increase is accounted for by disorders associated with degenerative changes in the central nervous system for which the authors lack remedies at the present time.

The British Journal of PsychiatryCAMDEX: A Standardised Instrument for the Diagnosis of Mental Disorder in the Elderly with Special Reference to the Early Detection of Dementia

2,115 Citations1986Martin Roth, Elizabeth Tym +5 more

A new interview schedule for the diagnosis and measurement of dementia in the elderly is described and is acceptable to patients, has a high inter-rater reliability and the cognitive section has been shown to have high and specificity.

Bias in Mental Testing

1,865 Citations1980Arthur R. Jensen

CortexDementia: The Estimation of Premorbid Intelligence Levels Using the New Adult Reading Test

1,127 Citations1978Hazel E. Nelson, Anne O’Connell

The results from a group of patients with cortical atrophy and a control group demonstrated the superiority of the NART over the best previously available word list (the Schonell GWRT) in enabling higher and more accurate levels of intelligence to be predicted.

The British Journal of PsychiatryAssessment of Cognitive Decline in the Elderly by Informant Interview

352 Citations1988Anthony F. Jorm, A. E. Korten

Direct assessment of decline by informants may be a solution to the problem of contamination by pre-morbid ability which affects traditional cognitive screening instruments.

NeurologySurvival in Alzheimer's disease and vascular dementias

224 Citations1985Laurie Barclay, Alexander Zemcov +2 more

All three diagnostic categories had comparable progression of behavioral and cognitive impairment and need for home care or institutionalization at follow-up, but vascular dementias have higher mortality than DAT, even when associated with comparable cognitive and behavioral impairment.

International Journal of Geriatric PsychiatryAssessment of cognitive decline in dementia by informant questionnaire

99 Citations1989Anthony F. Jorm, Ruth Scott +1 more

An informant questionnaire to measure cognitive decline in the elderly (the IQCODE) was found to have high internal consistency reliability and to measure a general factor of cognitive decline.

Acta Psychiatrica ScandinavicaDuration of survival in senile dementia

58 Citations1986Han Diesfeldt, L. R. van Houte +1 more

The severity of behavioural and cognitive impairments predicted 1‐year survival after admission into a nursing home, as could be shown by multivariate analysis which corrected for the effects of age and sex.

A Longitudinal Study of Aging Human Twins

16 Citations1978Lew Bank, Lissy F. Jarvik

If within-pair differences are significantly smaller for one-egg than for two-egg pairs (i.e., if the one- egg pairs have the significantly higher concordance rates), then there is presumptive evidence for a significant influence of genetic factors on that trait.