Spine
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A retrospective cohort study. ⋯ 3.
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A retrospective study. ⋯ 4.
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Cross-sectional population-based observational study. ⋯ 2.
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A retrospective study. ⋯ 3.
A retrospective cohort study. ⋯ 3.
A retrospective study. ⋯ 4.
Cross-sectional population-based observational study. ⋯ 2.
A retrospective study. ⋯ 3.