MBP and Anxiety: The forest plots in Figure 2 indicate significant reduction in anxiety [6 Studies, 2,086 participants, SMD (95%CI) = −0.19 (−0.37, −0.01), I2 = 71%] with positive effects for sleep focussed interventions as well as multimodal interventions (PA, SB, diet, sleep) particularly effective interventions being the SidekickHealth App (36) and the Sleep Ninja App (42), SB-ED-App (37) and the MBP-Webapp (40).