Objective: Disability and pain are common complaints of patients seeking care for spinal disorders. The Neck Disability Index (NDI), Modified Low Back Pain Disability Questionnaire (MDQ), and the Single Assessment Numeric Evaluation (SANE) capture disability while the numeric pain rating scale (NPRS) aims to capture pain intensity. There is limited evidence evaluating the SANE, and pain relationships in patients with neck and back pain. The purpose of this study was to evaluate the correlations among these outcomes.

Methods: A retrospective study was initiated on patients with non-surgical back (n=104,108) and neck (n=53,012) episodes. Patients completed an initial and final MDQ or NDI and at least 1 of the following initial measures: resting NPRS, activity NPRS, or SANE. Pearson’s correlations were used to test concurrent validity.

Results: Strong correlations were found between final MDQ and resting pain (r=0.51) and pain with activity (r=0.55). Final NDI and resting pain(r=0.53) and pain activity(r=0.55) demonstrated strong correlations. Moderate correlations were found between initial MDQ and pain at rest (r=0.43) and pain activity (r=0.43), final MDQ and SANE (r=-0.35), initial NDI and pain at rest (r=0.47) and pain activity (r=0.45), and final NDI and SANE (r=-0.33). Weak correlations were found between initial NPRS and SANE in the MDQ sample; however final NPRS and SANE scores had moderate correlations in both the MDQ and NDI samples (r=-0.36-0.29). No correlations were observed between initial NPRS and SANE in the NDI sample.

Conclusions: The NDI and MDQ scoring appears to be influenced by pain, which may limit precision in representing true ability or function. The improvement of SANE and pain correlations at final visit reflects the combined effects of pain reduction, enhanced functional capacity, and potential psychological adaptation over the course of therapy, allowing patients to more accurately assess their pain in relation to the recovery process.