Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for the early diagnosis of dementia across a variety of healthcare settings

© 2014 The Cochrane Collaboration. This is the protocol for a review and there is no abstract. The objectives are as follows: To determine the diagnostic accuracy of the informant based questionnaire IQCODE in a population free from dementia for the delayed diagnosis of dementia. Where data are available, we will describe the following. 1. The delayed verification diagnostic accuracy of IQCODE at various thresholds. We recognise that various thresholds or 'cut-off' scores have been used to define IQCODE screen positive states, and thus various 'subthreshold' cut-points could be used to describe individuals with cognitive problems not diagnostic of dementia. We have not pre-specified IQCODE cut-points of interest, rather we will collect delayed verification test accuracy data for all cut-points described. 2. Effects of heterogeneity on the reported diagnostic accuracy of IQCODE for delayed verification dementia (see below). Items of specific interest will include case-mix of population, IQCODE test format, time since index test and healthcare setting.