Adaptation and validation of the Tower of London test of planning and problem solving in people with intellectual disabilities

Background There is a need for validated, standardised tools for the assessment of executive functions in adults with intellectual disabilities (ID). This study examines the validity of a test of planning and problem solving (Tower of London) with adults with ID. Method Participants completed an adapted version of the Tower of London (ToL) while day-centre staff completed adaptive function (Adaptive Behaviour Scale - Residential and Community: Second Edition, modified version) and dysexecutive function (DEX-Independent Rater) questionnaires for each participant. Correlation analyses of test and questionnaire variables were undertaken. Results The adapted ToL has a robust structure and shows significant associations with independent living skills, challenging behaviour and behaviours related to dysexecutive function. Conclusions The adapted ToL is a valid test for use with people with ID. However, there is also a need to develop other ecologically valid tools based on everyday planning tasks undertaken by people with ID.