A cross-cultural adaptation study on the validity and test-retest reliability of pain assessment tools in Albanian older adults with low back pain

Abstract

Introduction : Over the years, several standardized pain assessment tools have been developed, each with its own strengths, to help quantify pain intensity and its impact on patients' lives. Methods : To assess the validity of the four pain scales, the ability of participants was evaluated to accurately measure the construct of pain intensity. To evaluate the reliability of the pain intensity scales, were conducted tests for both internal consistency and test-retest reliability. Results : Two hundred patients (53.0% male mean age 68.59; SD 6.39) completed all four pain intensity scales. All instruments showed good to excellent test–retest reliability, with intraclass correlation coefficients (ICC) ranging from 0.825 for Faces Pain Scale (FPS) to 0.922 for Visual Analog Scale (VAS). Internal consistency was high across all scales (Cronbach’s α = 0.90–0.96). Construct validity was supported by strong component loadings (>0.90) and significant correlations between the scales. The VAS demonstrated the highest reliability (ICC = 0.922) and sensitivity (MDC = 0.061), while the Numeric Rating Scale (NRS), FPS, and Brief Pain Inventory Interference Scale (BPI-IS) also showed good reliability and validity, making all four appropriate for clinical use in Albanian older adults with low back pain. Conclusion : The VAS, NRS, FPS and BPI-IS are valid and reliable scales for the pain intensity measurement in Albanian population with low back pain.