Exploratory factor analysis of the pain outcomes profile.

The Pain Outcomes Profile (POP) is a brief, multidimensional measure intended to assess pain intensity, functioning, and affect. It is presented as a practical measure with clinical utility. Results of studies support its concurrent, construct and predictive validity at the scale level. However, there have been no published studies of the measure at the item level. The present study was intended to assess the construct validity of the POP by way of factor analysis. A sample of 447 assessments of patients at a chronic non-cancer pain outpatient treatment center was employed. The 20 substantive items comprising the POP were entered into a factor analysis with oblique rotation. Five salient factors were obtained. Item-inclusion was generally consistent with factor loadings although noteworthy exceptions were observed in the Fear, Mobility and Vitality scales. Recommendations for further study and limitations of the current project are delineated.