Background: People with intellectual disability who live in the community often have poor health and healthcare, partly as a consequence of poor communication, recall difficulties and incomplete patient health information. Materials and Methods: A cluster randomized-controlled trial with 2 x 2 factorial design was conducted with adults with intellectual disability to investigate two interventions to enhance interactions among adults with intellectual disability, their care providers and general practitioners (GPs). The interventions were the Comprehensive Health Assessment Program (CHAP), a one-off health review tool, and the "Ask" health diary, designed for ongoing use. Follow-up was for 12 months post-intervention. Evidence of health promotion, disease prevention and case-finding activities were extracted from GPs clinical records. Results: Increased health promotion, disease prevention and case-finding activity were found in the intervention groups using the CHAP. It had a positive impact on "Pneumococcus" vaccination (OR 7.4; 95% CI: 1.5-37.1), hearing testing (4.5; 1.9-10.7), Hepatitis A vaccinations (5.4; 1.8-16.3), vision testing (3.4; 1.4-8.3), and weight measurement (3.1; 1.5-6.4). There were no strong changes in the measured outcomes in the group who used the "Ask" health diary alone. Conclusions: The use of the CHAP increased health promotion, disease prevention and case-finding activity in adults with intellectual disability living in the community and confirms the previously demonstrated benefits of the CHAP can be extended to less formal residential settings. The use of the "Ask" health diary did not improve the measured healthcare activity, at least in the short term, although it may contribute in other ways towards better health.