“…A summary of quality assessments of 18 studies that had been screened showed that 14 studies have high quality and four studies of medium quality. Four studies of medium quality were two studies of Gao, Qin, Qian, and Liu (2013) , Wood, Byrne, Burke, Enache, and Morrison (2017) , and Yelsma, Brown, and Ellison (2002) . The quality of the study medium is due to not fulfilling random sampling criteria, participant anonymity, non-prospective study designs, and sampling from various sites.…”