Development and validation of the Learning Disabilities Needs Assessment Tool (LDNAT), a HoNOS-based needs assessment tool for use with people with intellectual disability.

BACKGROUND: In meeting the needs of individuals with intellectual disabilities (ID) who access health services, a brief, holistic assessment of need is useful. This study outlines the development and testing of the Learning Disabilities Needs Assessment Tool (LDNAT), a tool intended for this purpose. METHOD: An existing mental health (MH) tool was extended by a multidisciplinary group of ID practitioners. Additional scales were drafted to capture needs across six ID treatment domains that the group identified. LDNAT ratings were analysed for the following: item redundancy, relevance, construct validity and internal consistency (n = 1692); test-retest reliability (n = 27); and concurrent validity (n = 160). RESULTS: All LDNAT scales were deemed clinically relevant with little redundancy apparent. Principal component analysis indicated three components (developmental needs, challenging behaviour, MH and well-being). Internal consistency was good (Cronbach alpha 0.80). Individual item test-retest reliability was substantial-near perfect for 20 scales and slight-fair for three scales. Overall reliability was near perfect (intra-class correlation = 0.91). There were significant associations with five of six condition-specific measures, i.e. the Waisman Activities of Daily Living Scale (general ability/disability), Threshold Assessment Grid (risk), Behaviour Problems Inventory for Individuals with Intellectual Disabilities-Short Form (challenging behaviour) Social Communication Questionnaire (autism) and a bespoke physical health questionnaire. Additionally, the statistically significant correlations between these tools and the LDNAT components made sense clinically. There were no statistically significant correlations with the Psychiatric Assessment Schedules for Adults with Developmental Disabilities (a measure of MH symptoms in people with ID). CONCLUSIONS: The LDNAT had clinically utility when rating the needs of people with ID prior to condition-specific assessment(s). Analyses of internal and external validity were promising. Further evaluation of its sensitivity to changes in needs is now required.

Spatial processing of images and hemisphere function.

Forty subjects performed both of the following tasks. In the imagery task, simple dot patterns were presented for five seconds in free vision, followed by a three second fixation field. Subsequently, a circle was briefly presented in either the right or the left visual field and subjects were required to indicate whether or not the circle surrounded a point previously occupied by a dot. The perceptual task was similar except that the dot patterns remained on the screen while the circle was presented. Reaction times and error data indicated a left visual field advantage on the imagery task only, suggesting a right hemisphere superiority for extraction of spatial information from images.