Table 2.

Primary RCT included in meta‐analyses

Study, years	Stableforth et al. 1984	Kristiansen et al. 1988	Zyto et al. 1997	Fjalestad et al. 2010	Olerud et al. 2011	Olerud et al. 2011*	Boons et al. 2012	Fjalestad et al. 2012
Handoll et al. (2013)12	√	√	√	√	√	√
Li et al. (2013)16			√		√			√
Mao et al. (2014)17	√		√	√	√	√	√	√
Jia et al. (2014)14	√		√	√	√	√	√	√
Fu et al. (2014)13	√		√		√	√	√	√
Sun et al. (2015)15			√		√			√
Mao et al. (2015)18			√		√	√	√	√
Rabi et al. (2015)19	√		√	√	√	√	√
Li et al. (2016)20	√		√	√	√	√	√
Du et al. (2017)21			√		√	√		√

RCT, randomized controlled trails.

^* stands for different studies.