Open AccessMeasurement of Affective and Activity Pain Interference Using the Brief Pain Inventory ( BPI ): Cancer and Leukemia Group B 70903
Author(s) -
Atkinson Thomas M.,
Halabi Susan,
Bennett Antonia V.,
Rogak Lauren,
Sit Laura,
Li Yuelin,
Kaplan Ellen,
Basch Ethan
Publication year - 2012
Publication title -
pain medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.893
H-Index - 97
eISSN - 1526-4637
pISSN - 1526-2375
DOI - 10.1111/j.1526-4637.2012.01498.x
Subject(s) - brief pain inventory , medicine , mood , confirmatory factor analysis , chronic pain , psychology , physical therapy , clinical psychology , statistics , mathematics , structural equation modeling
Objective The B rief P ain I nventory ( 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 40–86, mean = 65.46, 77% W hite non‐ H ispanic) who had been administered the BPI as part of C ancer and L eukemia G roup 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 < 0.05) values for the three‐factor model (i.e., pain intensity, activity interference, and affective interference), were statistically superior in comparison with the one‐ and two‐factor models. This three‐factor structure was found to be invariant across age, mean prostate‐specific antigen, and hemoglobin levels. Conclusions These results confirm that the BPI can be used to quantify the degree to which pain separately interferes with affective and activity aspects of a patient's everyday life. These findings will provide clinical trialists, pharmaceutical sponsors, and regulators with confidence in the flexibility of the BPI as they consider the use of this instrument to assist with understanding the patient experience as it relates to treatment.