The screening of mild dementia with a shortened Spanish version of the "Informant Questionnaire on Cognitive Decline in the Elderly".

Most of the present screening tests for the detection of dementia fail with mild dementia. Jorm et al. recently presented the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), a simple instrument with good diagnostic validity that uses a close relative to obtain information on the cognitive decline of a patient. We used a Spanish adaptation of this questionnaire (S-IQCODE) validated in a population-based sample, and a shortened form (SS-IQCODE) obtained after analyzing the items and reducing them to only 17. The S-IQCODE and the SS-IQCODE have greater diagnostic validity for mild dementia than the Mini-Mental State Examination (MMSE) (sensitivity: 86% for both versus 57%; specificity: 92 and 91% versus 84%, positive predictive value: 54 and 50% versus 29%; negative predictive value: 91 and 90% versus 81%) and, unlike the MMSE, are independent of the age, education, and previous intelligence of the subjects. According to the results of this study, the SS-IQCODE could be a useful screening test for the detection of mild dementia in the Spanish-speaking aged population, with greater diagnostic power and less contamination by independent variables than the MMSE.