. 2019 Aug 6;4(8):513–518. doi: 10.1302/2058-5241.4.180054

Table 2.

Newcastle Ottawa scale ratings.

Study (author, year)	Selection	Comparability	Exposure/outcome
Park et al., 2010¹³	****	**	***
Kim et al., 2010¹²	****	*	***
Ru et al., 2016¹⁴	****	*	***