The Overt Behaviour Scale-Self-Report (OBS-SR) for acquired brain injury: exploratory analysis of reliability and validity.

The objectives were to test the properties, via a psychometric study, of the Overt Behaviour Scale-Self-Report (OBS-SR), a version of the OBS-Adult Scale developed to provide a client perspective on challenging behaviours after acquired brain injury. Study sample 1 consisted of 37 patients with primary brain tumour (PBT) and a family-member informant. Sample 2 consisted of 34 clients with other acquired brain injury (mixed brain injury, MBI) and a service-provider informant. Participants completed the OBS-SR (at two time points), and the Awareness Questionnaire (AQ) and Mayo Portland Adaptability Inventory-III (MPAI-III) once; informants completed the OBS-Adult and AQ once only. PBT-informant dyads displayed "good" levels of agreement (ICC2,k = .74; OBS-SR global index). Although MBI-informant dyads displayed no agreement (ICC2,k = .22; OBS-SR global index), the sub-group (17/29) rated by clinicians as having moderate to good levels of awareness displayed "fair" agreement (ICC2,k = .58; OBS-SR global index). Convergent/divergent validity was demonstrated by significant correlations between OBS-SR subscales and MPAI-III subscales with behavioural content (coefficients in the range .36 -.61). Scores had good reliability across one week (ICC2,k = .69). The OBS-SR took approximately 15 minutes to complete. It was concluded that the OBS-SR demonstrated acceptable reliability and validity, providing a useful resource in understanding clients' perspectives about their behaviour.