The Health Intervention Package includes a comprehensive health review, called the Comprehensive Health Assessment Program (CHAP), which is performed by the adolescent's general practitioner, and a diary, the Ask diary, used to collect and store health information and to enhance health advocacy skills. We specifically aim to test if adolescents with intellectual disability using this package will receive better health screening and prevention (our primary outcomes). We also aim to test if using the package results in improved health advocacy by adolescents with intellectual disability and their parents (our secondary outcomes). The tool should also be acceptable to those involved (another secondary outcome). To investigate these aims we propose a clustered randomised controlled trial, a methodology we have used successfully in two previous trials. We will recruit 1000 adolescents (and their carers and teachers) in Special Education Schools and Special Education Units in Queensland.