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The evidence suggests that unhealthy lifestyles tend to increase health care use at any given age and reduce life expectancy, so more is spent per year but for fewer years.Pawel Dwulit

Chris Auld is Associate Professor in the Department of Economics at the University of Victoria and a scientist at the Centre for Addictions Research of British Columbia. He also maintains the blog

The idea that a healthy lifestyle substantially decreases demand on the health care system has been repeatedly shot, stabbed, and poked at with sharp sticks, but it won't just die.

The zombie argument goes like this: poor health causes more use of the health care system. Poor health can be caused by an unhealthy lifestyle -- smoking, overeating, lack of exercise, and so on. Therefore, unhealthy lifestyles cause increased use of the health care system. In Canada, health care costs are largely covered by the government, so my costs affect your wallet. Therefore, policies which induce people to choose healthier lifestyles are rigorously justified since they mitigate such external effects and reduce demand on the public health care system. For example, last week Mike DeJong, B.C.'s Minister of Health, commented on a smoking cessation program:

Quitting smoking is not only good for your health and the health of those around you, but it is also good for our health-care system as it will avoid the millions of dollars it costs to treat respiratory illnesses, health disease and cancer.

This is obvious and common reasoning, implicitly or explicitly motivating many policies. And it has been well-known to be wrong for decades.

The basic problem with the argument that healthy lifestyles decrease health care use is it draws attention only to the gross costs of treating illnesses caused by unhealthy behaviors, but the relevant costs are net of the costs which would otherwise be incurred under a healthier lifestyle.

Consider smoking, perhaps the most commonly studied health-affecting behavior. It is very well-established that smoking causes poor health. We can estimate the amount of health care used treating smoking-related illnesses by comparing disease rates for smokers and non-smokers and attributing some fraction of cases of various diseases to smoking. For example, Rehm et al (2006) estimate that in 2002, 2,210,155 hospital days were used treating illnesses attributable to smoking at a cost of about $2.5-billion.

However, all people -- and I do not mean to shock anyone -- die some time, even including people who live very healthy lifestyles. Preventing someone from dying of a smoking-related illness only means that they will die of a non-smoking related illness. The effect of smoking on lifecycle health care costs is the difference between costs which are incurred if the person smokes and the costs which would be incurred if the person doesn't smoke. Whether improvements in lifestyle increase or decrease lifetime health care costs depends in a complicated manner on how a healthy lifestyle affects length of life and health care costs at any given age. Whether smoking or other unhealthy behaviors increase or decrease health care costs is an empirical question.

The evidence suggests that unhealthy lifestyles tend to increase health care use at any given age and reduce life expectancy, so more is spent per year but for fewer years. For example, statistical estimates from a well-known 1997 paper are displayed in the graph. The lower two lines show that if we compare a smoker and a non-smoker who are the same age, we should expect to find that the smoker consumes more health care. But the top two lines show that health care costs for non-smokers eventually become much higher than those for smokers simply because smokers on average die sooner than non-smokers. This study estimated that if every smoker were to spontaneously quit, demand on the health care system would first fall, as the quitters become healthier than they otherwise would be, but eventually rise by 7 per cent in the long run as smokers live longer.

The upshot of this literature is that sometimes an unhealthy lifestyle is estimated to decrease net health care costs and sometimes to increase net costs, but these changes are small relative to the gross costs of treating lifestyle-induced illnesses. Nonetheless, studies which estimate the gross costs of treating illnesses are commonly discussed as if they are the net costs: An analyst or advocate adds up the costs of treating illnesses attributable to some behavior and refers to those costs as the social financial burden attributable to the behavior. Such exercises are misleading, as logic dictates that the net and not gross costs are what we need to know to assess that burden.

There are many reasons other than financial transfers through publicly provided health care to encourage healthy lifestyles, but we must remember when assessing policies to differentiate between the health effects and the financial effects of a policy.

A policy which increases health may also increase long-run health costs and may still be good policy. We should not argue that because health is increased health care costs will fall, nor should we argue that unhealthy lifestyles and publicly provided health care imply a large financial transfer to people leading unhealthy lifestyles from people leading healthier lifestyles.

The zombie notion that promoting healthy lifestyles is a good way of reducing demand on the health care system should be put to rest.

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