Table 1.

General characteristics of the included studies

Author	Region	Study design	Study population	Sample size	P (%)	Quality	Quality assessment result (%)
Gesesew H et al./2018 [17]	Oromo	Retrospective cohort	Adults	4900	67.7	low risk	72.73%
Abdu z etal/2014 [14]	SNNPRS	Retrospective cohort	Adults	714	34.4	low risk	63.6%
Gebru T etal/2018 [13]	SNNPRS	Retrospective cohort	Adults	320	50.5	low risk	54.6%
Gesesew/2016 [18]	Oromo	Retrospect cohort	Adults	289	59.9	low risk	63.6%
Abaynew y etal/ 2011 [16]	Amhara	case-control	Adults	320	not applicable	low risk	70%
Gesesew HA etal/2013 [15]	Oromo	case-control	Adults	309	not applicable	low risk	60%
Gelaw YA, etal/2015 [12]	Tigray	case-control	Adults	442	not applicable	low risk	70%
Asrat A/2010 [19]	Hareri	case-control	Adults	274	not applicable	low risk	60%