For many people, prime-time medical dramas such as "Grey's Anatomy" and "House" can't be beat for heart-stopping thrills and compelling story lines.
But while most regard these programs as pure entertainment, new research suggests that the shows may also be an important source of health information for their audiences.
That is what is suggested by the findings of a study, released Tuesday, that assesses the impact of health messages embedded within an episode of "Grey's Anatomy."
Lead researcher Victoria Rideout, vice president of the Kaiser Family Foundation and director of the Program for the Study of Media and Health, says the new study shows more clearly than ever how health messages embedded in TV programs can affect audience awareness of medical issues.
"It's very hard, actually, to come up with hard documentation about the impact of an entertainment show on the awareness of health issues," Rideout told ABCNews.com. "This is one of the very few large-scale national response experiments [on health messages in entertainment]."
To measure the impact of health messages in medical dramas, researchers worked with the writers of "Grey's Anatomy" to embed a health message in an episode of the popular program. In this case, the storyline involved a pregnant woman who was HIV positive, and the message was that she had a 98 percent chance of having a healthy baby with the proper treatment.
Viewers of the episode completed a survey before and after the episode aired. What the researchers found was that while only 15 percent of viewers knew before the show that mother-to-child transmission of HIV was overwhelmingly preventable, 61 percent were familiar with this fact after viewing the episode.
A followup survey found that nearly half of viewers -- 45 percent -- retained this information six weeks later.
"I knew that people learn from television, even entertainment television, but I was absolutely astounded at the level of learning happening here," Rideout said.
"Given how many people are multitasking when they are watching TV ... the fact that nearly half of the audience picked up on the factual information in the show and remembered it later was actually astounding."
Jay Bernhardt, director of the National Center for Health Marketing at the U.S. Centers for Disease Control and Prevention (CDC), said at a press conference Tuesday that the study suggests entertainment TV may be a largely unexploited tool when it comes to reaching the masses with important health information.
"The data suggest that the public still turns to television for a great deal of health information, not only [from] the news media, not only PSAs ... but also entertainment programming is an important source of health information," Bernhardt said. "It is critical for us, as the nation's public health agency, to have accurate, timely, relevant health information through that channel that people can use to protect and promote their health... That means using every single medium at our disposal to do so."
The new research was not the first to suggest that medical shows can have a profound effect on viewers' ideas about health.
Sandra de Castro Buffington, director of Hollywood, Health and Society for the University of Southern California's Annenberg Norman Lear Center, noted during the conference that a 2000 survey showed that "More than half -- 52 percent of regular viewers -- report that they trust the health information in these shows to be accurate.
"One-quarter -- 26 percent -- say primetime entertainment shows are among their top three sources for health information," she added.
The Scalpel Cuts Both Ways
But with many medical shows focusing on rare, medical mysteries, can audiences also get the wrong idea from medical shows?
"I think it's very likely," Rideout said, citing other studies that she and her colleagues have performed. "We did research that showed that six in 10 shows do have health information in them. By far, the biggest category is rare and mysterious diseases."
Taking such messages to heart could possibly be terrifying for some, who might subsequently believe that their common symptoms are a sign of a rare, difficult-to-treat affliction.
"The point is, there is a lot of health information out there, and people are learning from the health information that's out there -- for better or for worse," Rideout said. "We need to be paying attention to what health information is in these entertainment shows."
But Dr. George Pratt, vice chairman of psychology at Scripps Memorial Hospital in La Jolla, Calif., said even when the shows dramatize medical conditions, the net result can be a good one.
"Even if we're talking about the flipside, I think that it can even be a positive, because it gets people talking and thinking," Pratt said. "It contributes to an elevated interest and motivation to be responsible and vigilant with regard to your own health.
"Let's say something is hyped. This does still have a positive effect of having people take steps toward a greater degree of awareness."
Exploiting a Widespread Health Tool
"That's a really unusual way for medical storylines to be developed on our show," said Elizabeth Klaviter, director of medical research for the popular medical shows "Grey's Anatomy" and "Private Practice," both of which are broadcast by ABC.
But Klaviter said that constant consultation with medical experts ensures that such messages get out on a regular basis.
And such medical messages may have the welcome side effect of increasing the health knowledge of viewers.
"Health literacy is incredibly important," Rideout said. "We need to do more to educate the public about how they should educate themselves -- how to judge and assess the quality of the health information they get through entertainment. I think this is something that the CDC is very interested in moving forward on."