Association of physical inactivity with circulatory disease events and hospital treatment costs

Rachel C Davey,¹ Thomas Cochrane<sup>1,2

1</sup>Centre for Research and Action in Public Health, University of Canberra, ACT, Australia; ²Centre for Sport and Exercise Research, Staffordshire University, Stoke on Trent, United Kingdom

Purpose: Epidemiological studies of chronic disorders need to consider more responsive outcomes, particularly those that manifest themselves across a defined population over a shorter time period, to improve our ability to detect the causes of and intervene in the global epidemics of today. We explore the use of hospital episode statistics as a candidate for this role and estimate the strength of the association of circulatory disease-related events with physical inactivity, considered here as an undesirable health behavior.
Settings, patients, and methods: The primary research was set in a mid-sized city in central England. Aggregation was at output area level (comprising ~300 residents); 51 of which were included. A random sample of 761 adults was selected to obtain estimates of the mean level of physical activity within each area. Circulatory disease hospital events were recorded and aggregated by output area over a 2-year period. Hierarchical linear modeling was used to establish the strength of the association between area-level physical activity and circulatory disease events. Sex, age, and reporting quarter were included as additional individual-level explanatory variables.
Results: Areas reporting greater activity were less likely (event rate ratio = 0.855; 95% confidence interval [CI]: 0.78–0.94) to have a circulatory disease event, as were females (0.593; 95% CI: 0.47–0.75). Areas with older residents (1.578; 95% CI: 1.5–1.66) and later reporting quarters (1.095; 95% CI: 1.04–1.15) were more likely to report circulatory disease events.
Conclusion: This study supports the use of hospital episode statistics as an outcome measure in the epidemiology of circulatory disease and reaffirms the potential importance of physical inactivity in the disease process.

Keywords: exercise, cardiovascular disease, lifestyle, physical environment, chronic disease epidemiology