A confirmatory factor analysis of an electronic format painDETECT questionnaire for patients with low back pain

Abstract

Background

The substantial burden of low back pain on patients and healthcare systems is exacerbated by unclear pathology and ineffective diagnostic methods, hindering effective management. The painDETECT questionnaire (PD-Q) has been used to facilitate the evaluation and categorization of low back pain. While preliminary validation and translations of the paper-based format of PD-Q into languages such as Spanish and Dutch have been accomplished, the underlying factor model inherent to the electronic format of the PD-Q remains to be established.

Objective

The objective of this study was to utilise confirmatory factor analysis (CFA) to investigate the factor structure of an electronic format PD-Q among patients with neuropathic low back pain.

Methods

This cross-sectional study was conducted at a Spinal Clinic in Sydney between November 2020 and October 2022. Eligible participants were adults over 18 with low back pain and no history of lumbar surgery or systemic co-morbidities. Participants completed the electronic format of the PD-Q, and CFA was employed to assess the validity of the suggested two-factor, nine-item structure. Recommended cut-offs for goodness-of-fit indices were used to evaluate the model fit.

Results

Of the 236 patients that visited the clinic during the data collection period, 142 (71, 50% female, mean age 51.26 ± 15.28 years) participated in the study. Median pain severity was 9/10 over 4 weeks. CFA indicated strong model fit, with goodness-of-fit and comparative fit indices over 0.9, and overall internal consistency was 0.77. Construct validity analysis demonstrated the PD-Q’s effectiveness in distinguishing neuropathic, mixed, and nociceptive LBP, aiding neuropathic pain evaluation in low back pain patients.

Conclusion

This study confirms the reliability and two-factor structure of the electronic PD-Q for neuropathic pain assessment in low back pain patients. To enhance comprehension of the clinical applicability of the electronic format PD-Q, future research should conduct clinimetric evaluations.

Keywords:

• PainDETECT Questionnaire
• low back pain
• neuropathic pain
• confirmatory factor analysis (CFA)

Transparency

Declaration of financial/other relationships

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose. This work was supported by The University of New South Wales University Postgraduate Award.

Author contributions

Conceptualization and methodology: SL, AD; literature review: all authors; manuscript writing: all authors; critical review and revisions: SL, SS, AD; data collection: SL, AD; data analysis and data interpretation: SL, SS, AD; review and approval of the final manuscript: all authors. Corresponding author: SL.

Acknowledgements

The authors would like to acknowledge Cherie Tatsis of Spine Service and Sedricx Fontanilla for their valuable contributions to data collection.

Data availability statement

The data that support the findings of this study are available from the corresponding author, SL, upon reasonable request.

Ethics statement

The study was approved by the Human Research Ethics Committee of the University of Wollongong (HREC No. 2020/329).

Additional information

Funding

SL was supported by the University of Wollongong 2020 Health Impacts Research Centre (HIRC) Small Research Projects Grant Scheme and the Southern Cross University Re-establishing Research and Publishing Program (2023). SS benefits from an Australian Government Research Training Program scholarship. AD is the Director of Spine Service at the Department of Orthopaedic Surgery, St. George Hospital, University of New South Wales and the Spine Labs is sustained through unrestricted research grants bestowed by Baxter Inc and NuVasive Inc to the institution.