Assessment of pain and disability in patients with chronic low back pain: Reliability and construct validity of the Turkish version of the Quebec Back Pain Disability Scale and Pain Disability Index

Abstract

Objectives: The objective of this study was to test the reliability and validity of the Turkish version of the Quebec Back Pain Disability Scale (QBPDS) and Pain Disability Index (PDI) as well as the retainment of the psychometric properties of the original versions. The importance of the region-specific functional measures on patients with chronic low back pain was also assessed. Methods: Eighty-three patients with chronic low back pain were enrolled in the study. The QBPDS, the PDI and The Hospital Anxiety and Depression Scale (HADS) were filled by all subjects. Reliability was determined by internal consistency. Internal consistency was measured by calculating Cronbach's alpha and item-total correlation. Validity was examined by correlating the QBPDS and PDI scores to external criteria scores at a single point in time, defined as cross-sectional construct validity. Results: Cronbach's alpha value for QBPDS and PDI was found 0.93 and 0.84 respectively, which were both statistically significant (p < 0.0001). The item-total correlations of QBPDS varied between 0.28 and 0.76, and that of PDI varied between 0.30 and 0.73. The cross-sectional construct validity coefficients of QBPDS were 0.63 for PDI, 0.46 for Visual Analogue Scale (VAS), 0.28 and 0.16 for HADS. Correlation coefficients of PDI were 0.49, and those of VAS and HADS were 0.36 and 0.24 respectively. Conclusion: Our results are in accordance with the previous findings of the English and French versions of the QBPDS and English version of the PDI, indicating that these functional scales are valid and reliable. However, due to the considerable overlap between generic and region-specific functional instruments, the use of both scales is not necessary. We conclude that the QBPDS and PDI both measure predominantly functional status in patients with chronic low back pain.

Quebec Back Pain Disability Scale was responsive and showed reasonable interpretability after a multidisciplinary treatment

“…Developed by Kopec et al in 1995 [3], it has ever since been used in many studies [4e7] and translated into several languages (Iranian [8], Dutch [9], French [10], and Turkish [11]). Its good measurement properties (reproducibility and validity) have been reported [1e3, 8,9].…”

A valid cross-culturally adapted simplified Chinese version of the Quebec Back Pain Disability Scale

“…The SC-QDS internal consistency was excellent, with the Cronbach a reaching 0.976, higher than that of all other versions: original (0.96) [9], Dutch (0.95) [17], Iranian (0.92) [19], Brazilian (0.97) [20], Turkish (test, 0.941 and retest, 0.957) [21,22], Polish (0.95) [23], and Korean (0.92) [24]. It was noteworthy that the SC-QDS Cronbach a was limited to a very small range (0.974e0.976) if an item was deleted.…”

“…The summed total score indicates disability extent, ranging from 0 (no disability) to 100 (maximal disability). The QDS has been successfully adapted for measuring LBP impairment in several different cultural and language groups, including Dutch [17], French [18], Iranian [19], Brazilian [20], Turkish [21,22], Polish [23], and Korean [24]. However, no validated SC-QDS version has been reported.…”

Reliability and Factorial Validity of the Turkish Version of the Pain Disability Index in Rheumatic Patients With Chronic Pain

“…In the study of Biçer et al 25 in Turkey, Cronbach's alpha of the PDI was found to be 0.84. However, our investigation is characterized by more reliable and generalizable results thanks to our larger sample size (212 participants in our study versus 83 in Biçer's study), higher item total correlation, and inclusion of a variety of musculoskeletal diseases that cause chronic pain; whereas in Biçer's study, the sample consisted of patients with low back pain.…”