Using the ICF and psychological models of behavior to predict mobility limitations

Objective: To test the ability of a model that integrates the theory of planned behavior (TPB) into the International Classification of Functioning, Disability and Health (ICF), to predict walking limitations in adults awaiting hip or knee replacement surgery. Study Design and Participants: Cross-sectional structural equation modeling study of activity limitations in 190 adults. Method: A postal questionnaire measuring TPB, ICF, and walking limitations. Results: The integrated model accounted for more variance in activity limitations (57%) than did either TPB or ICF alone. Control beliefs (TPB) significantly mediated the relationship between impairment (ICF) and activity limitations. Conclusions: The integrated model provides an interdisciplinary, theoretical framework that identifies intervention targets to effect reductions in disability without the need for concomitant reductions in impairment.