Physical Activity Levels and New Public Transit: A Systematic Review and Meta-analysis.

CONTEXT: Physical inactivity is a public health concern as it contributes to the rising burden of noncommunicable diseases. Introducing new public transportation options, such as extending or building new light rail or bus rapid transit stations, could encourage commuters to walk to and from public transit stops, thus increasing their physical activity levels. Despite previous research generally finding positive associations between public transit usage and physical activity levels, few have summarized the association between introducing new public transportation options and different intensities of physical activity. This study aimed to systematically review the current evidence and perform a meta-analysis on this association.

EVIDENCE ACQUISITION: Ten databases were systematically searched for studies published between 1997 and 2017. To ensure comparability, study outcomes were converted to MET hours/week. A random effects meta-analysis and sensitivity analysis were then conducted.

EVIDENCE SYNTHESIS: Nine studies were identified to be included in the systematic review, of which five were eligible for meta-analysis. Pooled results suggest that building new public transit options is associated with a statistically significant increase in light to moderate physical activity levels by 1.76 MET hours/week (95% CI=0.19, 3.32, p=0.03). This is equivalent to increasing walking and other light to moderate physical activity by about 30 minutes per week, relative to baseline. No significant effect was found for the moderate to vigorous physical activity outcome.

CONCLUSIONS: Results show new public transit options can substantially contribute to increasing low- to moderate-intensity exercise levels, which has the potential to improve health on a population scale.