The associations between participation in certain sports and lower mortality are not explained by affluence and other socioeconomic factors

Our recent paper1 examined the type-specific associations between sports and all cause and cardiovascular disease (CVD) mortality. Among the wide media attention,2 CNN reported our finding as ‘Swimming, aerobics, racquet sports slash risk of death’3 and those three sports that showed the largest reductions in mortality risk (as indicated by the HR value).4 Running and football (soccer)/rugby5 showed limited beneficial associations with mortality. While it was beyond the capacity and scope of our research to undertake comparisons between different sports and explain why these three specific types of sports were associated with the largest reductions in risk, much of the media commentary2 was consumed with aetiological explanations3 5–7 of the beneficial associations that participation in certain sports conferred. On the other hand, an alternative explanation is that our findings of lower mortality did not reflect the health attributes of the examined sports but, instead, they were related to socioeconomic characteristics of the participants of certain sports. For example, as football is perceived to be lower social status sports, the smaller association with mortality could be seen as an indication that our models were not adequately adjusted for socioeconomic status and affluence. Racquet sports, aerobics and swimming usually involve paying for participation and/or equipment and as such may indicate …