Measurement of Affective and Activity Pain Interference Using the Brief Pain Inventory (BPI): Cancer and Leukemia Group B 70903

Objective The Brief Pain Inventory (BPI) was designed to yield separate scores for pain intensity and interference. It has been proposed that the pain interference factor can be further broken down into unique factors of affective (e.g., mood) and activity (e.g., work) interference. The purpose of this analysis was to confirm this affective/activity interference dichotomy. Patients and Methods A retrospective confirmatory factor analysis was completed for a sample of 184 individuals diagnosed with castrate-resistant prostate cancer (age 4086, mean?=?65.46, 77% White non-Hispanic) who had been administered the BPI as part of Cancer and Leukemia Group B trial 9480. A one-factor model was compared against two-factor and three-factor models that were developed based on the design of the instrument. Results Root mean squared error of approximation (0.075), comparative fit index (0.971), and change in chi-square, given the corresponding change in degrees of freedom (13.33, P?