Table 2.

Quality of the included studies assessed using the Newcastle-Ottawa quality assessment scale (NOS)

Study	NOS
	Selection	Comparability	Outcome	Total score
Sang et al.6				8
Himwaze et al.7				8
Yao et al.8				8
Mucheleng'anga et al.9				8
Dal Ferro et al.10				7
Romanova et al.11				7
Bryce et al.12				7
Elezkurtaj et al.13				8
Hooper at al.14				8
Falasca et al.15				8
De Michele et al.16				8
Edler et al.17				8
Menter et al.18				8
Satturwar et al.19				8