What Are the Health Benefits of Active Travel? A Systematic Review of Trials and Cohort Studies

BackgroundIncreasing active travel (primarily walking and cycling) has been widely advocated for reducing obesity levels and achieving other population health benefits. However, the strength of evidence underpinning this strategy is unclear. This study aimed to assess the evidence that active travel has significant health benefits.MethodsThe study design was a systematic review of (i) non-randomised and randomised controlled trials, and (ii) prospective observational studies examining either (a) the effects of interventions to promote active travel or (b) the association between active travel and health outcomes. Reports of studies were identified by searching 11 electronic databases, websites, reference lists and papers identified by experts in the field. Prospective observational and intervention studies measuring any health outcome of active travel in the general population were included. Studies of patient groups were excluded.ResultsTwenty-four studies from 12 countries were included, of which six were studies conducted with children. Five studies evaluated active travel interventions. Nineteen were prospective cohort studies which did not evaluate the impact of a specific intervention. No studies were identified with obesity as an outcome in adults; one of five prospective cohort studies in children found an association between obesity and active travel. Small positive effects on other health outcomes were found in five intervention studies, but these were all at risk of selection bias. Modest benefits for other health outcomes were identified in five prospective studies. There is suggestive evidence that active travel may have a positive effect on diabetes prevention, which may be an important area for future research.ConclusionsActive travel may have positive effects on health outcomes, but there is little robust evidence to date of the effectiveness of active transport interventions for reducing obesity. Future evaluations of such interventions should include an assessment of their impacts on obesity and other health outcomes.研究背景：增加主动出行（active travel，主要为步行与骑行）已被广泛倡导，用于降低肥胖水平并实现其他人群健康收益。然而，支撑该策略的证据强度尚不明确。本研究旨在评估主动出行具有显著健康收益的相关证据。 研究方法：本研究采用系统综述（systematic review）设计，纳入两类研究：(i) 非随机对照试验（non-randomised controlled trials）与随机对照试验（randomised controlled trials），(ii) 前瞻性观察研究（prospective observational studies），且这些研究需围绕(a) 促进主动出行的干预措施的效果，或(b) 主动出行与健康结局之间的关联展开。通过检索11个电子数据库、相关网站、参考文献列表以及领域专家提供的文献，识别符合要求的研究报告。本研究纳入针对普通人群、测量主动出行相关健康结局的前瞻性观察研究与干预研究，排除针对特定患者群体的研究。 研究结果：本研究共纳入来自12个国家的24项研究，其中6项是以儿童为研究对象的研究。5项研究对主动出行干预措施进行了评估，其余19项为未评估特定干预措施影响的前瞻性队列研究（prospective cohort studies）。未发现以成人肥胖为结局指标的相关研究；在5项针对儿童的前瞻性队列研究中，仅1项发现肥胖与主动出行之间存在关联。5项干预研究显示主动出行对其他健康结局存在小幅正向影响，但这些研究均存在选择偏倚（selection bias）风险。5项前瞻性研究发现主动出行对其他健康结局具有适度收益。现有证据提示，主动出行或对糖尿病预防具有正向作用，这可能是未来研究的重要方向。 研究结论：主动出行或对健康结局存在正向影响，但目前尚无充分可靠的证据证明主动出行干预措施在降低肥胖方面的有效性。未来对这类干预措施的评估应包含其对肥胖及其他健康结局的影响分析。