Importance of a functional measure in the evaluation of patients in a memory clinic: Validation of the Serbian version of the Amsterdam instrumental activities of daily living questionnaire

Abstract

Introduction and aim: The Amsterdam instrumental activities of daily living questionnaire (A-IADL-Q) was developed as a sensitive tool in detecting a functional decline in early dementia. The aim of our study was to analyze the validity and reliability of the Serbian translation of the short version of A-IADL-Q in a population of memory clinic patients.

Material and methods: We have included 160 subjects with Alzhemier's disease (AD) dementia, mild cognitive impairment (MCI), or normal cognition (NC). All patients were examined by a neurologist, screened for cognitive impairment (MMSE) and depression, and referred to laboratory testing, neuroimaging examination, and neuropsychological assessment. Informants (close friends or relatives) completed Serbian language versions of the A-IADL-Q -Short version and the Lawton-Brody Instrumental Activities of Daily Living (LB-IADL) scale. Reliability analysis was performed by assessing internal consistency and reproducibility (test-retest reliability). Construct validity was assessed as the impact of gender, аgе, education, diagnosis, cognitive and functional measures on A-IADL-Q scores.

Results: The internal consistency of the Serbian version of A-IADL-Q was acceptable (Cronbach's alpha 0.82), Test-retest reliability of the A-IADL-Q was excellent (ICC=0.92, 95% CI 0.84-0.98, p < 0.001). There was no statistically significant difference in A-IADL-Q scores between male and female subjects (t = 1.183; p = 0.241), while the difference was registered between subjects with different education levels (F=12.955; p < 0.001) and diagnosis (F=209.433; p < 0.001). There was a strong and statistically significant correlation between A-IADL-Q and MMSE scores (tau-b= 0.638; p < 0.001) and IADL-Q and LB-ADL scores (tau-b=0.714; p < 0.001). A significant multiple regression model was found (F(4, 155) = 103.692;p < 0.001), which explained 72.1% of the A-IADL-Q score variance with MMSE score and age as significant predictors.

Conclusion: The Serbian adaptation of the A-IADL-Q-short version is a reliable and valid measure of instrumental activities of daily living in patients with dementia and mild cognitive impairment. This easy-to-administer instrument is useful for the early diagnostics of dementia syndrome in a memory clinic population.

Keywords: Alzheimer's disease; Dementia; Instrumental activities of daily living; Questionnaire; Validation.