Objective: To develop measures representing key constructs of the Transtheoretical Model (TTM) of behavior change as applied to advance care planning (ACP) and to examine whether associations between these measures replicate the relationships posited by the TTM.
Methods: Sequential scale development techniques were used to develop measures for Decisional Balance (Pros and Cons of behavior change), ACP Values/Beliefs (religious beliefs and medical misconceptions serving as barriers to participation), Processes of Change (behavioral and cognitive processes used to foster participation) based on responses of 304 persons age≥65 years.
Results: Items for each scale/subscale demonstrated high factor loading (>.5) and good to excellent internal consistency (Cronbach α .76-.93). Results of MANOVA examining scores on the Pros, Cons, ACP Values/Beliefs, and POC subscales by stage of change for each of the six behaviors were significant, Wilks'λ=.555-.809, η(2)=.068-.178, p≤.001 for all models.
Conclusion: Core constructs of the TTM as applied to ACP can be measured with high reliability and validity.
Practice implications: Cross-sectional relationships between these constructs and stage of behavior change support the use of TTM-tailored interventions to change perceptions of the Pros and Cons of participation in ACP and promote the use of certain Processes of Change in order to promote older persons' engagement in ACP.
Published by Elsevier Ireland Ltd.