Validity of the Brief Pain Inventory for Use in Documenting the Outcomes of Patients With Noncancer Pain

TLDR

The Brief Pain Inventory was originally designed for cancer patients but is increasingly used in studies of non‑cancer pain. This study formally evaluates the reliability and validity of the BPI in patients with non‑cancer pain. A cohort of about 250 arthritis or low‑back‑pain patients completed the BPI and other health status measures at baseline and after treatment in a primary‑care clinic. The BPI showed acceptable reliability (α > 0.70), replicated factor structure, strong correlations with generic pain scales, discriminated severity levels, and detected change over time, confirming its validity for arthritis and low‑back‑pain patients.

Abstract

Objectives: The Brief Pain Inventory (BPI) is a short, self-administered questionnaire that was developed for use in cancer patients. While most empirical research with the BPI has been in pain of that etiology, the questionnaire is increasingly evident in published studies of patients with non-cancer pain. The current research addresses the need for formal evaluation of the reliability and validity of the BPI for use in non-cancer pain patients. Methods: Approximately 250 patients with arthritis or low back pain (LBP) self-administered a number of generic and condition-specific health status measures (including the BPI) in the clinic of their primary care provider at 2 time points: the initial clinic visit and the first visit following treatment. Results: The reliability of BPI data collected from non-cancer pain patients was comparable to that reported in the literature for cancer patients and sufficient for group-level analyses (coefficient alphas were greater than 0.70). The factor structure of the BPI was replicated in this sample and the relationship of the BPI to generic measures of pain was strong. The BPI exhibited similar relationships to general and condition-specific measures of health as did a generic pain scale (SF-36 Bodily Pain). Finally, the BPI discriminated among levels of condition severity and was sensitive to change in condition over time in arthritis and LBP patients. Discussion: Results support the validity of the BPI as a measure of pain in patients without cancer and, in particular, as a measure of pain for arthritis and LBP patients.