Peskin says MetLife adjusted rates two years ago for policyholders suffering from coronary heart disease and undergoing modern treatments, such as angioplasty--topics of much recent epidemiology research.

"The literature showed that these treatments were very effective and so we did reduce hundreds of thousands of people's health insurance premiums by as much as 50 percent," says Peskin. "It was an acknowledgement that some these treatments were in fact working."

Sanders says changes in response to new medical techniques were not immediate, and that any changes would affect the amount of benefits, not the specific illnesses covered.

"Most of the coverage that we provide is mandated by the state, so there's very little in a contract that pertains to specific diseases," says Sanders. "It might affect the level of benefits for instance under mental nervous benefits, or restrictions on total benefits paid out, but under group insurance contracts there's typically not a line-item exclusion for certain diseases."

For instance, acupuncture is covered in California, says Sanders, because of a state mandate, but not in Massachusetts.

According to Kane, companies generally base group health insurance premiums on industry classes, rather than epidemiologic studies. She says insurance companies compile tables of statistics for different industries, and determine premiums according to the risks peculiar to each industry.

For example, health insurance rates for bars and restaurants may be high because smoking may be more prevalent there.

"The classes can get pretty specific," says Kane. She says that beauty salons are a separate class, because there is a high HIV infection rate there. Construction workers are another group that would fall under a different set of premiums.

But risk factors are still taken account for individuals seeking personal health insurance. According to Peskin, individual policyholders are asked if they smoke or have high blood pressure.

Kane says premiums based on small group or individual experiences were more easily skewed because a single member who used a significant amount of health insurance in the past could greatly distort the group's health rating.

"They're trying to get rid of that [system], and that's what a lot of insurance reform right now is about," says Kane. "They're trying to price people according to utilization, and getting to a community rating."

But is money being wasted in discovering the same relationships twice? In the end, says Kane, epidemiologic studies merely confirm the statistics amassed by insurance companies.

"The medical establishment figures out the why, the insurance industry is projecting on what is," she says. "Medical research is just confirming the scientific and systematic causes."

Medical researchers produce hundreds of studies per year, warning us that our habits are unhealthy and may lead to any number of life-threatening conditions. But should we take all of them seriously?