. 2007 Oct 16;4(10):e297. doi: 10.1371/journal.pmed.0040297
© 2007 Vandenbroucke et al.
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Flow diagram from Hay et al. [141].
![Flow diagram from Hay et al. [141].](https://www.ncbi.nlm.nih.gov/core/lw/2.0/html/tileshop_pmc/tileshop_pmc_inline.html?title=Click%20on%20image%20to%20zoom&p=PMC3&id=2043000_pmed.0040297.g001.jpg)