A newly released study made use of a custom algorithm to find that unhealthy lifestyle habits are reducing the life expectancy of Canadians by an average of six years. The study looked at the results of the 2009-2010 Canadian Community Health Survey in order to develop its findings, which include that unhealthy lifestyles contribute to roughly half of all deaths in Canada.
Obviously, the idea that things like smoking and not eating well shorten the lifespan is not new or contested. What this study did was try and put a more solid number on how these and other activities impact the lives of Canadians. For instance, the study found that 26% of all deaths were attributable to smoking, 24% had connections to physical inactivity, 12% of deaths were attributable to poor diet, and 0.4% of deaths were linked to unhealthy alcohol consumption.
When broken up by gender, smoking was the top risk factor for men and resulted in a life expectancy loss of 3.1 years on average. For women, the largest loss in life expectancy was 3 years from physical inactivity. It is worth pointing out that these numbers are averages and a large spectrum of findings went in to calculating them.
For instance, when Canadians who showed the unhealthiest behaviors were compared to those with the most healthy behaviors (as defined by government recommendations), the latter group had a 17.9 greater life expectancy.
When they get studied, behaviors are usually tied to life expectancy changes through aggregate data. While this helps get averages, it makes determining equity between groups or individuals trickier. What this recent study tried to do was develop a multivariable predictive algorithm of health behaviors and mortality (MPoRT) that would be able to use individual data, rather than aggregate information, to create findings.
The findings of this MPoRT study suggest that such algorithms can produce valid calculations and may be useful tools in supplementing the data created by aggregate approaches. The uses go beyond calculating the life expectancy changes of Canadians and could be used to better asses the impacts of other activities in various nations, not necessarily just unhealthy lifestyle habits.
Manuel, D., “Measuring Burden of Unhealthy Behaviours Using a Multivariable Predictive Approach: Life Expectancy Lost in Canada Attributable to Smoking, Alcohol, Physical Inactivity, and Diet,” PLOS Medicine, 2016;