The aim of this study was to evaluate the psychometric properties of the Brief Pain Inventory (BPI) as well as tests of its reliability, validity, and discriminative utility for estimating the status of chronic pain in neuropathic and nociceptive pain patients.
Method and patients
We enrolled 224 chronic pain (126 neuropathic pain and 98 nociceptive pain) patients. The original version of the BPI was translated into Turkish by standard procedures. An independent clinician determined the pain type. The factor analysis, reliability (internal consistency and test–retest reliability), and validity (agreement with the reference diagnosis and sensitivity, specificity, and positive and negative predictive values) were determined. Discriminant function analysis was then employed to determine whether BPI could differentiate between neuropathic and nociceptive pain.
Cronbach's α-coefficient was 0.84 for the test and 0.83 for the retest. BPI scores for subjects did not significantly differ between applications r:0.96 (P < 0.01). Principal axis factoring with oblimin rotation revealed three interpretable factors: severity scale, activity interference, and sleep and mood interference. Compared to the clinical assessment, sensitivity, specificity, and positive and negative predictive values for criterion total BPI score were 79.37%, 46.9%, 65.8%, and 63.9%, respectively.
The results suggest that Turkish version of BPI is a reliable and valid evaluation measure of neuropathic and nociceptive pain patients. This is the first study reporting the comparison and validation of psychometric properties of BPI in neuropathic and nociceptive pain group. Our data suggest that BPI may able to discriminate the origin of chronic pain.