. 2021 Mar;21(1):159–165. doi: 10.4314/ahs.v21i1.21
© 2021 Khairwa A.
Licensee African Health Sciences. This is an Open Access article distributed under the terms of the Creative commons Attribution License (https://creativecommons.org/licenses/BY/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Figure 2.
Subgrouping of the 49 studies in four