To test and cross-validate a model using disease activity, pain, and helplessness to predict future psychological and physical disability in persons with rheumatoid arthritis (RA) across time.
Measures of disease activity, pain, helplessness, psychological function, and physical function were collected from 63 males with RA at baseline, 3 months, and 6 months. Path analytic methods were used to examine longitudinal relationships among these variables.
Path analysis revealed that pain and helplessness were significant mediators of the relationship between disease activity and future disability in RA; the predictive model withstood two cross-validations.
The findings suggest that pain and helplessness are key biopsychosocial variables that affect the development of disability in RA.