“…Results of the risk of bias assessment are presented in Table 1. Only one of the included records was assessed as having a low risk of bias across all five domains and that was for only one of the interventions within the trial (Schonenberg et al, 2017), and nine records were assessed as having a low risk of bias in four out of five domains (Dittner, Hodsoll, Rimes, Russell, & Chalder, 2018; Gu, Xu, & Zhu, 2018; Janssen et al, 2018; Philipsen et al, 2015; Salomone et al, 2015; Stern, Malik, Pollak, Bonne, & Maeir, 2016; Vidal et al, 2013; Young et al, 2015, 2017). For a significant number of studies, it was not possible to assess the risk of bias in at least one of the five domains due to insufficient information.…”