Purpose: To develop and evaluate the psychometric properties of measures of advocacy activity and perceived control specific to those affected by acquired brain injury (ABI).
Method: Questionnaires, including initial forms of the Advocacy Activities Scale (AAS) and Perceived Control Scale for brain injury (PCS-BI), Craig Hospital Inventory of Environmental Factors, Satisfaction with Life Scale and SF-12, were mailed through the State Brain Injury Associations in three states in the Upper Midwestern U.S. Through multiple mailings, 322 (21.4%) complete response sets of 1550 possible were obtained; 196 from individuals with ABI, 99 from significant others (SOs), and 27 with no indication of whether the respondent was a person with BI or SO. The AAS and PCS-BI were analyzed and refined using a two parameter item response theory model. Concurrent validity was examined through simple correlations and principal components analyses of all measures.
Results: After modification based on IRT analyses, the AAS showed satisfactory internal consistency (Person reliability = 0.77; item reliability = 0.97) as did the PCS-BI (Person reliability = 0.78; item reliability = 0.99). Although more complex than the predicted, relationships with other measures supported the concurrent validity of the AAS and PCS-BI.
Conclusions: The AAS and PCS-BI are reliable and valid measures of advocacy activity and an associated sense of perceived control among those affected by ABI for use in survey research and assessing the effectiveness of interventions to increase advocacy activity.