[Adaptation and validation of CAMDEX-DS (Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and others with intellectual disabilities) in Spanish population with intellectual disabilities].

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.