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. 2017 Sep 18;7(9):e016760. doi: 10.1136/bmjopen-2017-016760

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© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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The expert clinical researcher’s approach to selecting variables in a CRF for clinical research. CRF, case report form; PICO, patient/population/problem—intervention—comparison—outcome.