Disease prevention doesn't take place just in the clinic. The majority of preventive measures -- from brushing teeth to wearing seatbelts -- happen in the community and workplace.
And here the cost-benefit balance sheet is very different, some studies say, when you consider the cost not only to healthcare providers but also to employers and government, which might invest in antismoking campaigns or publicly accessible exercise programs.
"In many cases, if not most cases, prevention activities are more cost-effective than treatment," says Ron Z. Goetzel, a research professor at Emory University in Atlanta and vice president of the healthcare division at Thomson Reuters, an information company with headquarters in New York City.
Heart disease and cancer are big killers in the U.S., so it makes sense for the country to fund measures targeting obesity and smoking, both risk factors for those diseases, Goetzel says.
A 2008 report from Trust for America's Health, a nonprofit based in Washington, D.C., suggests that when society makes small investments in community-based intervention, it can yield major savings.
The study authors examined 84 published reports of preventive interventions, such as providing park areas for exercise or improving nutrition in school lunches, and calculated the costs and benefits associated with such measures.
The report estimated that an investment of $10 per person, from a variety of sources in society, would, within five years, save the country more than $16 billion in treatment costs every year.
"There are significant numbers of interventions that literally cost dollars per person," says Richard Hamburg, deputy director of Trust for America's Health.
However, Louise Russell, a research professor at the Institute for Health, Health Care Policy and Aging Research at Rutgers, the State University of New Jersey in New Brunswick, said that the report does not include all costs of health behavior changes -- to individuals, employers and communities.
For example, some interventions in the study were programs to inform people about healthy living. "But a media campaign has no effect until people react to it," Russell says. And for people to exercise or cook more healthful foods, she says, they'll run up additional costs of time and money not included in the calculation.
Many employers are developing incentives for workers to develop healthful habits, hoping not only to save on healthcare costs but also to increase productivity because employees are out sick less. In a 2008 paper in the Annual Review of Public Health, Goetzel noted that several studies show counseling employees with health risks to change their behavior results in overall savings.
The effort is cost-effective even if only a few people adopt healthier lifestyles, Goetzel says. "Even those small changes in the risk profile of the population . . . can yield large dollar savings."