Associations of Regular Internet Usage with All-Cause and Cause-Specific Mortality: A Prospective Cohort Study

OBJECTIVES: The impact of internet usage on mortality is not widely known. This study intended to investigate the associations between regular internet usage and the risks of all-cause and cause-specific mortality, while also ascertaining potential factors that may modify these correlations. DESIGN: A community-based prospective cohort study. SETTING AND PARTICIPANTS: The study included 21,481 individuals [mean (SD) age, 64.1 (11.0) years] from the Health and Retirement Study, with data collected between 2006 and 2020. METHODS: The Cox proportional hazards regression model was used to evaluate the associations between regular internet usage and the risks of all-cause and cause-specific mortality, adjusting for demographic factors, lifestyle behaviors, and other potential confounding factors. Moreover, we explored the association between daily hours of internet usage and the risk of outcomes. RESULTS: Regular internet usage was significantly associated with a lower risk of all-cause mortality (hazard ratio, 0.78; 95% CI, 0.74-0.83) and cardiovascular mortality (hazard ratio, 0.72; 95% CI, 0.64-0.82). No significant interaction effects were observed for age, sex, regular exercise, or current alcohol consumption (all P interactions > .05). Additionally, estimations for daily hours of usage indicated a U-shaped relationship with all-cause mortality. Adults who used 2.1 to 4 hours per day had the lowest risk; however, not all estimations showed their significance on account of the limited sample size. CONCLUSIONS AND IMPLICATIONS: Regular internet usage was associated with a lower risk of all-cause and cardiovascular mortality, which may prompt consideration of the beneficial impact of internet usage on lifespan.