INTRODUCTION
Dementia caused by Alzheimer's disease commonly affects the adult population with Down's syndrome. This population presents two characteristic clinical features: a semiologic pattern that differs from the typical Alzheimer's disease, and previous intellectual deficits that may confound the clinical diagnosis. There is a clear need to validate specific instruments adapted to Spanish population.
AIM
To adapt and to validate CAMDEX-DS (Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and Others with Intellectual Disabilities) in Spanish population.
PATIENTS AND METHODS
146 patients with intellectual disability (mild to moderate) were recruited and assessed with CAMDEX-DS, K-BIT I and DMR tests. Test-retest reliability, inter-rater concordance and validity statistic were performed between CAMDEX-DS and clinical diagnosis. This is an observational, multicenter, cross-sectional and validation study.
RESULTS
Test-retest and inter-rater reliability achieved kappa coefficient values of 0.92 and 0.91, respectively. Agreement (kappa index) for CAMDEX-DS on clinical diagnosis compared to other clinical criteria was high: CAMDEX-DS vs DSM-IV (kappa = 0.95; p < 0,001); CAMDEX-DS vs ICD-10 (kappa = 0.97; p < 0.001). All item-test correlations ranged between 0,31 and 0,69. Internal reliability-calculated using Chronbach's alpha scored 0.93.
CONCLUSIONS
The Spanish version of CAMDEX-DS is a valid instrument with high applicability for people with intellectual disability. It shows good psychometric properties. The Cambridge Cognitive Examination for Older Adults with Down's Syndrome (CAMCOG-DS) can set two key points by the level of intellectual disability on the suspicion of cognitive impairment in people with Down's syndrome.