A clearly stated aim

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Inclusion of consecutive patients

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A description of inclusion and exclusion criteria

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Inclusion of patients

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Prospective collection of data. Data were collected according to a protocol established before the beginning of the study

Did they say ‘prospective’, ‘retrospective’ or ‘follow up’? The study is not prospective when it is a chart review, database review, clinical guideline, or practical summaries.
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Outcome measures

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Unbiased assessment of the study outcome and potential risk factors

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Were the determinant measures used accurate (valid and reliable)?

For studies where the determinant measures are shown to be valid and reliable, the question should be answered adequate. For studies that refer to other work that demonstrates the determinant measures are accurate, the question should be answered as adequate.
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Loss to followup

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Adequate statistical analyses

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