Objective: To determine the association between the self-report of pain and disability and findings on lumbar MR images, and to compare two different health care providers in Spanish patients with low back pain (LBP).
Design: Cross-sectional
Material and methods: A total of 278 patients, 137 men and 141 women aged 44+/-14 years submitted with low back pain (LBP) were studied. One hundred and nine patients were from the National Health System (NHS) and 169 from private practice. Patients with previous discitis, surgery, neoplasm or traumatic episodes were excluded. Every patient completed a disability questionnaire with six core items, providing a score of disability from 2 to 28. All patients had sagittal spin-echo T1 and turbo spin-echo T2, axial proton-density and MR myelography weighted images. MR images of the two most affected disc levels were read, offering an MR imaging score from 0 to 30.
Results: Patients with a combination of LBP and sciatica showed the highest levels of disability (p=0.002). MR imaging scores only correlated with pain interference with normal work (p=0.04), but not with other disability questions. Patients from the NHS showed greater disability scores than private ones (p=0.001) and higher MR imaging scores (p=0.01).
Conclusion: In patients with LBP, MR imaging only correlates with pain interference with work but not with other disability questions. Differences are found between private and NHS patients, the latter being more physically affected.