No. of participants (No. of studies) | Design | Quality assessment | Absolute effect | Quality | |||
---|---|---|---|---|---|---|---|
Risk of bias | Inconsistency | Indirectness | Imprecision | ||||
The mean age at exposure measurement ranged from ~29 to 53 months (~2.4 to 4.4 yr). Data were collected longitudinally up to 8 years of follow-up. Fitness was assessed as: lower body explosive strength (standing long jump) and fitness level (parent-report level relative to other children). | |||||||
1314 (2) | Longitudinala | Serious risk of biasb | No serious inconsistency | Serious indirectnessc | No serious imprecision | Screen-based sedentary behaviours: Higher TV time (hr/day) at age ~29 mo was unfavourably associated with standing long-jump performance (cm) at age 97.8 mo (B = −0.361; 95% CI: −0.576, −0.145; p < 0.001) [89] and physical fitness level (scale from −2 to 2) in Grade 4 (β = −0.09, SE = 0.0004; B = −0.01, 95% CI: −0.002, −0.02; p < 0.01) [90]. A greater increase in TV time (hr/week) between age ~29 and ~53 months was unfavourably associated with standing long-jump performance (cm) at age 97.8 months (B = −0.285; 95% CI: −0.436,-0.134; p < 0.01) [89] and physical fitness level (scale from −2 to 2, relative to other children) in Grade 4 (β = −0.10, SE = 0.0003, p < 0.01) [90]. | Very lowd |