The Outcomes and Impact Scale - Revised: the psychometric properties of a scale assessing the impact of service provision

BACKGROUND: The Outcomes and Impact Scale - Revised (O&IS-R) was developed to measure the impact of service provision on adults with disability. The aim of this research was to explore the psychometric properties of the scale following a recent revision. METHOD: Adults with disability and/or their carers or support workers participated in the research. Participants were recruited across Australia using a range of strategies and completed the scale in relation to a service or support that they nominated. Two forms of the scale were developed (easy and standard English), which could be completed in hardcopy or via a bespoke website. RESULTS: The O&IS-R demonstrated good internal consistency and alternate form reliability. Factor analysis of the scale revealed one factor that clearly corresponded to the whole of life construct that the scale was designed to measure and, in general, participants with disability and staff understood the intent or purpose of the survey. All domains except the spiritual and political domain were considered to be relevant service outcomes. Some changes to wording were suggested to improve clarity. CONCLUSIONS: The O&IS-R is a psychometrically sound scale that can be used in service and research settings to measure the impact of services and supports