Preventative medicine is often touted as the best way to decrease the long-term costs of health care. It is important to note however, that though many preventative measures are cost-effective and result in decreased incidence of disease, there are many that do not necessarily provide savings; albeit, they certainly still may decrease the incidence or prevalence of disease and improve health care.
How does this work? Well, let's begin with the conventional thought on how preventative medicine saves health care costs. The best example would be the consumption of tobacco. By decreasing smoking through prevention, there will undoubtedly be less illness as a consequence of the consumption of cigarettes and therefore a decreased health care cost. Because it costs relatively little to stop people from smoking when compared to the cost of treatment for smoking-related illnesses, for example, a net monetary benefit can be appreciated.
On the other hand, other preventative measures, such as those that may prevent a particular but rare cancer, may not be as cost effective. Indeed, in the article "Does preventive care save money? Health economics and the presidential candidates," published in the NEJM in 2008 by Cohen et al., the authors describe this particular dilemma.
Prevention is in the end a positive way to improve health care, but because costs have to be considered, not all forms of preventative medicine are financially feasible. What this means is that, though there are preventative measures that could have a discernible impact on improving population health, the costs associated for implementing them are high, and thus, if enforced, do not decrease health care costs.