Abstract: We identified one new trial from the updated searches. Seven trials (347 participants) met the selection criteria. The interventions varied but had common components: interventions that increased the intensity and frequency of service delivery (4 trials, 200 participants), community-based specialist behaviour therapy (1 trial, 63 participants), and outreach treatment (1 trial, 50 participants). Another trial compared two active arms (traditional counselling and integrated intervention for bereavement, 34 participants). The included studies investigated interventions dealing with the mental health problems of persons with an intellectual disability; none focused on physical health problems. Four studies assessed the effect of organisational interventions on behavioural problems for persons with an intellectual disability, three assessed care giver burden, and three assessed the costs associated with the interventions. None of the included studies reported data on the effect of organisational interventions on adverse events. Most studies were assessed as having low risk of bias. It is uncertain whether interventions that increase the frequency and intensity of delivery or outreach treatment decrease behavioural problems for persons with an intellectual disability (two and one trials respectively, very low certainty evidence). Behavioural problems were slightly decreased by community-based specialist behavioural therapy (one trial, low certainty evidence). Increasing the frequency and intensity of service delivery probably makes little or no difference to care giver burden (MD 0.03, 95% CI -3.48 to 3.54, two trials, moderate certainty evidence). It is uncertain whether outreach treatment makes any difference for care giver burden (one trial, very low certainty evidence). There was very limited evidence regarding costs, with low to very low certainty evidence for the different interventions. There is very limited evidence on the organisation of healthcare services for persons with an intellectual disability. There are currently no well-designed studies focusing on organising the health services of persons with an intellectual disability and concurrent physical problems. There are very few studies of organisational interventions targeting mental health needs and the results of those that were found need corroboration. There is an urgent need for high-quality health services research to identify optimal health services for persons with an intellectual disability and concurrent physical problem.

Plain-language summary: We searched for all relevant studies until 4 September 2015. We found seven studies, six of which we identified previously and one retrieved for this update. All of the studies assessed the impact of the intervention on the mental health of persons with an intellectual disability; none considered the physical health. Those studies used different interventions, including giving persons with an intellectual disability more health services, psychological support, and treating them at home, instead of at the hospital. Studies mainly looked at how the interventions helped the behavioural problems of those with an intellectual disability, how much burden they caused the care givers, and how much they cost. No study assessed adverse events. Community-based behaviour therapy might decrease behavioural problems. We are uncertain whether other interventions make any difference in reducing behavioural problems. There was limited evidence about how those interventions helped care givers to deal with the burden of caring for their relatives with an intellectual disability, or how much they might cost compared with the usual care already provided. uthors' conclusions There is little information on different ways to organise services for people with intellectual disabilities. Most studies focused on people who had intellectual disabilities and mental health problems. There were no studies on people who had intellectual disabilities and physical problems.