caa a22 4500 386353301 CHVBK 20180307111841.0 cr unu---uuuuu 161130e198911 xx s 000 0 eng 10.1017/S0033291700005742 doi S0033291700005742 pii (NATIONALLICENCE)cambridge-10.1017/S0033291700005742 The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE): socio-demographic correlates, reliability, validity and some norms [Elektronische Daten] 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. Copyright © Cambridge University Press 1989 Jorm A. F. NH & MRC Social Psychiatry Research Unit, The Australian National University, Canberra, Australia Jacomb P. A. NH & MRC Social Psychiatry Research Unit, The Australian National University, Canberra, Australia Psychological Medicine Cambridge University Press 19/4(1989-11), 1015-1022 0033-2917 19:4<1015 1989 19 PSM https://doi.org/10.1017/S0033291700005742 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0033291700005742 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Jorm A. F. NH & MRC Social Psychiatry Research Unit, The Australian National University, Canberra, Australia NATIONALLICENCE 700 1- Jacomb P. A. NH & MRC Social Psychiatry Research Unit, The Australian National University, Canberra, Australia NATIONALLICENCE 773 0- Psychological Medicine Cambridge University Press 19/4(1989-11), 1015-1022 0033-2917 19:4<1015 1989 19 PSM CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge