No. of participants (No. of studies) | Design | Risk of bias | Inconsistency | Indirectness | Imprecision | Other | Absolute effect | Quality |
---|---|---|---|---|---|---|---|---|
6095 (4) | Clustered RCT | No serious risk of bias | No serious risk of inconsistency | Very serious risk of indirectnessa | No serious risk of imprecision | None | Overall:  • 1/4 studies reported null findings  • 2/4 studies reported unfavourable findings  • 1/4 studies reported mixed findings   • 1: null and unfavourable  • 1/4 studies also compared types of sedentary behaviours Active Lessons:  • 2/4 studies reported unfavourable findings [111, 112]  • 1/4 studies reported mixed findingsb   • 1: Null and unfavourable [113]  • 1/4 studies compared types of sedentary   • 1: Sedentary game was favourable compared to sedentary lesson [113] Additional PA:  • 1/1 studies reported null findings [49] | Low |
49 (1) [85] | Non-Randomised Intervention | No serious risk of bias | No serious risk of inconsistency | No serious risk of indirectness | Very serious risk of imprecisionc | None | Standing Desks:  • 1/1 study reported favourable findings [85] | Very Low |
4656 (4) | Longitudinal | Serious risk of biasd | No serious risk of inconsistency | No serious risk of indirectness | No serious risk of imprecision | None | Overall:  • 1/4 studies reported null findings  • 3/4 studies reported mixed findings   • 2: Null and unfavourable   • 1: Null and favourable Active Breaks:  • 1/1 studies reported mixed findingse   • 1: Null and unfavourable [115] Homework:  • 1/3 studies reported null findings [114]  • 2/3 studies reported mixed findingsf   • 1: Null and unfavourable [57]   • 1: Null and favourable [116]   • 1: Mixed findings included dose response relationships with favourable associations for up to 2 h, but null associations for ≥2 h [116] | Very Low |
83,252 (12) | Cross-sectional | Serious risk of biasg | No serious risk of inconsistency | No serious risk of indirectness | No serious risk of imprecision | None | Overall:  • 2/12 studies reported null findings  • 1/12 studies reported favourable findings  • 1/12 studies reported unfavourable findings  • 8/12 studies reported mixed findings   • 2: Favourable and unfavourable   • 2: Null and unfavourable   • 3: Favourable and null   • 1: Favourable, null, and unfavourable Homework:  • 1/10 studies reported null findings [117]  • 1/10 studies reported favourable findings [118]  • 1/10 studies reported unfavourable findings [119]  • 7/10 studies reported mixed findingsh   • 3: Favourable and null [63, 65, 120]   • 2: Favourable and unfavourable [39, 121]   • 1: Null and unfavourable [122]   • 1: Favourable, null, and unfavourable findings [123]   • 1: Mixed findings included dose response relationships with favourable associations for 1–2 h/day and null associations for > 2 h/day [65] Sedentary time:  • 1/2 studies reported null findings [71]  • 1/2 studies reported mixed findingsi   • 1: Null and unfavourable [68] | Very Low |