This report describes the methodology for evaluating the Integrated Services Program, which establishes cross-agency responses for adult clients who have multiple and complex needs such as mental illness, intellectual disability and acquired brain injury and who exhibit behaviours that might cause significant harm. The evaluation examines longer-term client outcomes achieved by the Integrated Services Program and compares the outcomes of three client groups: those in the program, those having exited the program and those referred to but not accepted into the program. Our research aims to inform choices about cost and operationally effective models of service provision for people with multiple and complex needs.