Physical capability scale: psychometric testing.

The purpose of this study was to describe the psychometric testing of the Basic Physical Capability Scale. The study was a secondary data analysis of combined data sets from three studies. Study participants included 93 older adults, recruited from 2 acute-care settings and 110 older adults living in long-term care facilities. Rasch analysis was used for the testing of the measurement model. There was some support for construct validity based on the fit of the items to the scale across both samples. In addition, there was support for hypothesis testing as physical function was significantly associated with physical capability. There was evidence for internal consistency (Alpha coefficients of .77-.83) and interrater reliability based on an intraclass correlation of .81. This study provided preliminary support for the reliability and validity of the Basic Physical Capability Scale, and guidance for scale revisions and continued use.