Esther Yakobov, Whitney Scott, Michael Tanzer, William Stanish, Michael Dunbar, Glen Richardson, Michael JL Sullivan
Objective: Recent research has linked perceptions of injustice to problematic recovery outcomes for individuals with musculoskeletal injuries. However, the measure currently used to assess perceived injustice is not readily applicable to individuals who have a pain condition, such as osteoarthritis (OA), where pain onset is insidious as opposed to traumatic. The purpose of this study was to validate a modified version of the Injustice Experiences Questionnaire (IEQ-chr) for patients with OA of the knee.
Methods: The IEQ-chr was administered along with measures of pain catastrophizing, fear of movement, depressive symptoms, pain severity and physical function to 110 individuals with severe OA of the knee.
Results: Principal component analyses yielded a factor structure similar to that in the original validation study. The IEQ-chr had high internal consistency (Chronbach alpha=0.88), and was significantly correlated with pain catastrophizing, fear of movement, depressive symptoms, pain severity and physical function. Regression analyses revealed that the IEQ-chr contributed significant unique variance to prediction of pain severity and physical function, beyond the variance accounted for by measures of pain catastrophizing and fear of movement.
Conclusions: The findings of the present study support the construct validity of the IEQ-chr in the context of osteoarthritis, and suggest that this measure may be useful in psychosocial assessment of individuals at risk for adverse pain outcomes. The discussion addresses theoretical and clinical implications of these findings.