Spine
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Prospective research in middle-aged and elderly people. ⋯ 2.
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Prospective study. ⋯ 3.
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Retrospective. ⋯ 3.
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Retrospective cohort. ⋯ 4.
Prospective research in middle-aged and elderly people. ⋯ 2.
Prospective study. ⋯ 3.
Retrospective. ⋯ 3.
Retrospective cohort. ⋯ 4.