a1 NH&MRC Social Psychiatry Research Unit, The Australian National University, Canberra, Australia
Data from four studies were used to assess the psychometric properties of the 26 IQCODE items. The items were assessed in terms of item–total correlations, test–retest reliabilities, correlations with indicators of current cognitive functioning and correlations with indicators of pre-morbid cognitive functioning. These data were used to develop a 16-item short form. The short form was cross-validated in a new sample using dementia/delirium diagnosis as the validity standard. It was found to perform as well as the long form.
c1 Address for correspondence: Dr A. F. Jorm, NH&MRC Social Psychiatry Research Unit, The Australian National University, Canberra, ACT 0200, Australia.