Daily Step Count and All-Cause Mortality: A Dose-Response Meta-analysis of Prospective Cohort Studies

Background Uncertainty remains about the optimum step count per day for health promotion. Objective We aimed to investigate the association between step count per day and all-cause mortality risk. Methods PubMed, Scopus, and ISI Web of Science were searched to January 2021 to find prospective cohort studies of the association between device-based step count per day and all-cause mortality risk in the general population. Two reviewers extracted data in duplicate and rated the certainty of evidence using the GRADE approach. Study-specific hazard ratios (HRs) were pooled using a random-effects model. Results Seven prospective cohort studies with 175,370 person-years and 2310 cases of all-cause mortality were included. The HR for each 1000 steps per day was 0.88 (95% CI 0.83-0.93; I-2 = 79%, n = 7) in the overall analysis, 0.87 (95% CI 0.78-0.97; I-2 = 59%, n = 3) in adults older than 70 years, and 0.92 (95% CI 0.89-0.95; I-2 = 37%, n = 2) in studies controlled for step intensity. Dose-response meta-analysis indicated a strong inverse association, wherein the risk decreased linearly from 2700 to17,000 steps per day. The HR for 10,000 steps per day was 0.44 (95% CI 0.31-0.63). The certainty of evidence was rated strong due to upgrades for large effect size and dose-response gradient. Conclusions Even a modest increase in steps per day may be associated with a lower risk of death. These results can be used to develop simple, efficient and easy-to-understand public health messages.