Social Isolation and All-Cause and Cause-Specific Mortality in the UK Biobank: The Modifying Role of Non-Commute Transportation Mode

The study examined the relationship between social isolation and mortality in 490,114 participants from the UK Biobank aged 40-69 years followed from 2006 to 2022. Social isolation was associated with increased risk of all-cause mortality (hazard ratio 1.34) and cardiovascular mortality (hazard ratio 1.49). The mode of non-commute transportation modified this relationship: participants using only public transport showed a stronger association between isolation and cardiovascular mortality compared to those using only a car. Conversely, combining a car with active or public transport reduced the association between isolation and all-cause mortality. The findings suggest that mixed transportation including a car provides the greatest protective effect against the negative impacts of social isolation on mortality.