Psychometric Properties of the Brief Pain Inventory Among Patients With Osteoarthritis Undergoing Total Knee Arthroplasty Surgery.

Background: Knee osteoarthritis (OA) is characterized by pain and functional restrictions, necessitating precise and reliable pain evaluation for effective disease surveillance and postoperative treatment appraisal.

Methods: This investigation recruited 110 participants who were slated to receive unilateral total knee arthroplasty (TKA) and administered 3 self-reported questionnaires: the Brief Pain Inventory (BPI), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 5-level EuroQoL Group's 5-dimension questionnaire (EQ-5D-5L), at baseline and 1 year after surgery. Using standard statistical methods and indicators, the BPI was subjected to a battery of psychometric evaluations, including assessments of reliability, validity, and responsiveness.

Results: At baseline, there were no significant ceiling or floor effects observed. Additionally, the internal consistency reliability (Cronbach's alpha) of the BPI was above 0.8, suggesting that the questionnaire items are adequately related to one another. The study found moderate to very strong correlations between the pain and physical function domains of the BPI and Western Ontario and McMaster Universities Osteoarthritis Index, as well as a strong correlation between the functional interference dimension of the BPI and the EQ-5D, supporting the construct validity of the BPI. Also, the BPI was found to be responsive to changes in pain over time, with a responsiveness index ranging from 2.55 to 3.19.

Conclusion: The BPI assessment tool demonstrated good reliability, validity, and responsiveness in knee osteoarthritis patients who have undergone TKA and can be a useful measurement tool in clinical research to evaluate the effectiveness of pain management strategies and surgical interventions.