. 2015 Jan 13;17(1):e11. doi: 10.2196/jmir.3979
©Corine S Meppelink, Julia CM van Weert, Carola J Haven, Edith G Smit. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 13.01.2015.
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Figure 1.
Flow chart of the stratification procedure.