Short forms of Prudhoe Cognitive Function Test in adults and aging people with intellectual disabilities: Italian validation study.

BACKGROUND: We aimed to validate the Italian version of the two parallel short forms of the Prudhoe Cognitive Function Test (s-PCFT-I) in adults and seniors with intellectual disabilities (ID) of any aetiology and level of severity. METHODS: Our validation is a multicentre study attended by 211 subjects with ID, 125 male and 86 female, aged 40 years and above for people with Down syndrome and aged 50 years for people with other forms of disabilities. RESULTS: The s-PCFT-I shows a wide range of scores in the absence of floor effects with minimal ceiling effects. A Cronbach's α coefficient of 0.85 and a mean inter-item correlation of 0.21 indicate high internal consistency. The tool demonstrates good agreement between testers and near excellent temporal stability with intraclass correlation coefficients respectively of 0.85 and 0.90. s-PCFT-I total scores do not differ by sex or age, while statistically significant differences are observed between people with different levels of severity of ID. Moderate to good and highly significant correlations (-0.40 to -0.66) among the s-PCFT-I total scores and subscores and the Sum of Cognitive Score of the informant-based Dementia Questionnaire for Persons with Intellectual Disabilities suggest an acceptable level of concurrent criterion validity. Cognitive decliners according to Prasher's Dementia Questionnaire for Persons with Intellectual Disabilities cut-off scores perform significantly lower on s-PCFT-I than non-decliners. CONCLUSIONS: The s-PCFT-I has good psychometric properties and user friendliness and may therefore be a valuable addition to the current informant-rated tools for screening and assessment of cognition in aging people with ID.

Functional abilities and cognitive decline in adult and aging intellectual disabilities. Psychometric validation of an Italian version of the Alzheimer's Functional Assessment Tool (AFAST): analysis of its clinical significance with linear statistics and artificial neural networks.

PURPOSE: (a) A psychometric validation of an Italian version of the Alzheimer's Functional Assessment Tool scale (AFAST-I), designed for informant-based assessment of the degree of impairment and of assistance required in seven basic daily activities in adult/elderly people with intellectual disabilities (ID) and (suspected) dementia; (b) a pilot analysis of its clinical significance with traditional statistical procedures and with an artificial neural network. METHODS: AFAST-I was administered to the professional caregivers of 61 adults/seniors with ID with a mean age (± SD) of 53.4 (± 7.7) years (36% with Down syndrome). Internal consistency (Cronbach's α coefficient), inter/intra-rater reliabilities (intra-class coefficients, ICC) and concurrent, convergent and discriminant validity (Pearson's r coefficients) were computed. Clinical significance was probed by analysing the relationships among AFAST-I scores and the Sum of Cognitive Scores (SCS) and the Sum of Social Scores (SOS) of the Dementia Questionnaire for Persons with Intellectual Disabilities (DMR-I) after standardisation of their raw scores in equivalent scores (ES). An adaptive artificial system (AutoContractive Maps, AutoCM) was applied to all the variables recorded in the study sample, aimed at uncovering which variable occupies a central position and supports the entire network made up of the remaining variables interconnected among themselves with different weights. RESULTS: AFAST-I shows a high level of internal homogeneity with a Cronbach's α coefficient of 0.92. Inter-rater and intra-rater reliabilities were also excellent with ICC correlations of 0.96 and 0.93, respectively. The results of the analyses of the different AFAST-I validities all go in the expected direction: concurrent validity (r=-0.87 with ADL); convergent validity (r=0.63 with SCS; r=0.61 with SOS); discriminant validity (r=0.21 with the frequency of occurrence of dementia-related Behavioral Excesses of the Assessment for Adults with Developmental Disabilities, AADS-I). In our sample age and gender do not correlate with the scale and comparing the distribution of the AFAST-I and DMR-SCS and DMR-SOS expressed as ES, it appears that memory disorders and temporal and spatial disorientation (SCS) precede the loss of functional abilities, whereas changes in social behaviour (SOS) are less specific in detecting cognitive deterioration sufficient to provoke functional disability and vice versa. The results of AutoCM analysis reveal that the hub (core) of the entire network is represented by the functional domain 'personal/oral hygiene' in the entire study sample and 'use of toilet' in a subgroup of subjects who obtained an ES equal to 0 at DMR-SCS. CONCLUSIONS: These results confirm the reliability and validity of AFAST-I and emphasise the complexity of the relationship among functional status, cognitive functioning and behaviour also in adults/seniors with ID.