Abstract：
OBJECTIVE: This study aimed to describe the variability in estimates of the association of daily steps and all-cause mortality in systematic reviews with meta-analyses, to identify the factors potentially responsible for it, and to provide an updated estimate.
METHODS: Five databases were systematically searched up to May 2024 to identify systematic reviews with meta-analyses and prospective cohort studies. A qualitative synthesis of previous reviews and an updated meta-analysis of cohort studies were performed. Pooled hazard ratios (HRs) with their 95% confidence intervals (CIs) were calculated using a random-effects model.
RESULTS: Eleven systematic reviews with meta-analyses and 14 cohort studies were included, revealing considerable variability in result presentation. Our updated meta-analysis showed a nonlinear association, indicating a lower risk of all-cause mortality with increased daily steps, with a protective threshold at 3143 steps/day, and a pooled HR of 0.91 (95% CI: 0.87, 0.95) per 1000 steps/day increment. Physical activity categories consistently indicated progressively reduced mortality risk, with the highly active category (>12,500 steps/day) exhibiting the lowest risk (0.35 (95% CI: 0.29, 0.42)).
CONCLUSIONS: Systematic reviews and meta-analyses showed considerable variability in effect estimates due to different methods of quantifying exposure. Despite it, our study underscores the importance of increased daily steps in reducing all-cause mortality, with a minimum protective dose of 3000 steps/day, although the optimal dose differed according to age and sex. It is recommended that future studies categorise daily steps by physical activity category, perform dose-response analyses, and use increments of 1000 steps/day.
METHODS: Five databases were systematically searched up to May 2024 to identify systematic reviews with meta-analyses and prospective cohort studies. A qualitative synthesis of previous reviews and an updated meta-analysis of cohort studies were performed. Pooled hazard ratios (HRs) with their 95% confidence intervals (CIs) were calculated using a random-effects model.
RESULTS: Eleven systematic reviews with meta-analyses and 14 cohort studies were included, revealing considerable variability in result presentation. Our updated meta-analysis showed a nonlinear association, indicating a lower risk of all-cause mortality with increased daily steps, with a protective threshold at 3143 steps/day, and a pooled HR of 0.91 (95% CI: 0.87, 0.95) per 1000 steps/day increment. Physical activity categories consistently indicated progressively reduced mortality risk, with the highly active category (>12,500 steps/day) exhibiting the lowest risk (0.35 (95% CI: 0.29, 0.42)).
CONCLUSIONS: Systematic reviews and meta-analyses showed considerable variability in effect estimates due to different methods of quantifying exposure. Despite it, our study underscores the importance of increased daily steps in reducing all-cause mortality, with a minimum protective dose of 3000 steps/day, although the optimal dose differed according to age and sex. It is recommended that future studies categorise daily steps by physical activity category, perform dose-response analyses, and use increments of 1000 steps/day.
摘要：
目的：本研究旨在通过meta分析的系统评价来描述每日步数与全因死亡率的相关性估计值的变异性。为了确定可能造成这种情况的因素，并提供最新的估计。
方法：截至2024年5月，系统搜索了5个数据库，以通过荟萃分析和前瞻性队列研究确定系统评价。对以前的综述进行了定性综合，并对队列研究进行了更新的荟萃分析。使用随机效应模型计算集合风险比（HR）及其95％置信区间（CI）。
结果：纳入了11项系统综述和荟萃分析和14项队列研究，揭示了结果呈现的相当大的可变性。我们更新的荟萃分析显示出非线性关联，表明随着每日步数的增加，全因死亡率的风险较低，保护阈值为3143步/天，每1000步/天增量的合并HR为0.91(95%CI：0.87，0.95)。身体活动类别一致表明死亡风险逐渐降低，高活性类别（>12,500步/天）表现出最低风险（0.35（95％CI：0.29，0.42））。
结论：系统评价和荟萃分析显示，由于定量暴露的方法不同，效果估计存在相当大的差异。尽管如此,我们的研究强调了增加每日步骤对降低全因死亡率的重要性，最低保护剂量为3000步/天，尽管最佳剂量因年龄和性别而异。建议未来的研究按身体活动类别对每日步数进行分类，进行剂量反应分析，并使用1000步/天的增量。
方法：截至2024年5月，系统搜索了5个数据库，以通过荟萃分析和前瞻性队列研究确定系统评价。对以前的综述进行了定性综合，并对队列研究进行了更新的荟萃分析。使用随机效应模型计算集合风险比（HR）及其95％置信区间（CI）。
结果：纳入了11项系统综述和荟萃分析和14项队列研究，揭示了结果呈现的相当大的可变性。我们更新的荟萃分析显示出非线性关联，表明随着每日步数的增加，全因死亡率的风险较低，保护阈值为3143步/天，每1000步/天增量的合并HR为0.91(95%CI：0.87，0.95)。身体活动类别一致表明死亡风险逐渐降低，高活性类别（>12,500步/天）表现出最低风险（0.35（95％CI：0.29，0.42））。
结论：系统评价和荟萃分析显示，由于定量暴露的方法不同，效果估计存在相当大的差异。尽管如此,我们的研究强调了增加每日步骤对降低全因死亡率的重要性，最低保护剂量为3000步/天，尽管最佳剂量因年龄和性别而异。建议未来的研究按身体活动类别对每日步数进行分类，进行剂量反应分析，并使用1000步/天的增量。
