. 2021 Dec 12;29(2):498–510. doi: 10.1177/09697330211050998
© The Author(s) 2021
This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).
Figure 1.
PRISMA flow diagram. From: Moher et al. (2009).