Figure 2. Bias assessment of each study. Green means little bias risk, yellow means uncertain bias risk, and red means high bias risk.

Yurko-Mauro et al. [9]; Jackson et al. [10]; Witte et al. [11]; Konagai et al. [12]; Bauer et al. [13]; Jaremka et al. [14]; Külzow et al. [15]; Leckie et al. [16]; Maltais et al. [17].