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

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. 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. 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. 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. 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.