Spine
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Retrospective review and prospective validation study. ⋯ 2.
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A prospective cross-sectional study. ⋯ 4.
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Cross-sectional cohort study of chronic low back pain (CLBP) patients and matched controls. ⋯ 4.
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Retrospective longitudinal cohort. ⋯ 3.
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Cross-sectional cohort analysis. ⋯ 2.