Instrumental activities of daily living in the screening of dementia in population studies: a systematic review and meta‐analysis

BACKGROUND: Despite the fact that the current definitions of dementia in the DSM-IV and ICD-10 require functional deterioration for the diagnosis of dementia, it is not necessary a formal evaluation of functional capacity. OBJECTIVES: To examine the efficiency of functional assessment as a method of screening dementia in population studies. METHODS: This systematic review was based on information from MEDLINE, EMBASE, Index Médico Español (IME), and related articles. The studies included are population studies of patients over 65, in which normal and demented (established diagnosis) subjects are compared. In all of them, subjects were evaluated using the instrumental activities of daily living scale (IADL) as the method of screening for dementia. RESULTS: Two thousand three hundred and three abstracts and bibliographical references were reviewed. The authors of the selected studies were contacted and asked about other ongoing studies or indexes not included in our review in order to complete a meta-analysis. Finally, five studies were selected (n = 11.960). A meta-analysis was performed, with a statistical Q* value of 0.88 (SE 0.26). CONCLUSIONS: The functional assessment of the IADL showed an acceptable efficiency for the screening of dementia in the population studies included in this review, although few studies have verified this efficiency (sensitivity and specificity of the scales used). Further research is necessary in this field to be able to draw definitive conclusions.