More than half of Americans said they would consider splitting their prescription pills to save money if their doctor said it would not be detrimental to their health, according to results of a national poll conducted by Opinion Research Corp. and sponsored by UnitedHealthcare.

Yet while 57 percent of Americans overall would consider pill-splitting, only 9 percent of those currently taking medications that are safe to split are actually splitting their prescription pills in half. Respondents attributed the global economic downturn for spurring them to find ways to save money when it comes to health care and lifestyle choices.

According to the data, 27 percent of Americans currently taking medications said they are not taking their prescription medications as directed by their physician, including 18 percent who said they are foregoing their medicines altogether.

Still, only about a third (31 percent) of Americans have asked their doctor or pharmacist about ways to save money on prescription medicines, according to the poll results.

“Pill-splitting under the direction of a physician can be a simple and safe way to receive the benefits of certain prescription drugs at half the cost,” said Dr. Sam Ho, UnitedHealthcare’s executive vice president and chief medical officer. “Some of our health plan customers have saved almost $400 a year by splitting a single prescription through our voluntary Half Tablet Program.”

Not all prescription pills should be split, including certain medicines that require a finely tuned dosage to be effective, or have a protective coating that can be damaged in the splitting process. Yet many common medicines that are taken on a daily, long-term basis can safely be split, including Crestor, Lipitor, Cozaar, Diovan, Lexapro and Zoloft. These six medicines, on which Americans spent nearly $15 billion alone in 2008, are among the 21 branded and generic prescription drugs appropriate for splitting under UnitedHealthcare’s Half Tablet program.

UnitedHealthcare considers medicines with all of the following characteristics as potential candidates for splitting with a physician’s approval:

• tablets that can be split relatively evenly without crumbling;
• medicines that have a wide margin of safety so that minimal differences in tablet sizes will not result in either under-dosing or over-dosing;
• medications that remain stable after splitting.

A study published in the American Journal of Managed Care (June 2007) also found that consumers were willing to split their pills if it meant a reduction in their out-of-pocket expenses.

Human immune cells communicate constantly with one another as they coordinate to fight off infection and other threats. Now researchers at Stanford University’s School of Medicine have shown that muffling a key voice in this conversational patter is an early step in the progression of human cancers. Silencing an inter-cell signaling mechanism called the interferon pathway may be one way newly developing cancers gain the upper hand. It may also explain the immune dysfunctions seen in many cancer patients and why cancer immunotherapies are often ineffective.

“Over half of cancer patients mount an immune response against their own cancer,” said hematologist Peter P. Lee, MD, associate professor of hematology. “So, why does it so often fail? Our research indicates that cancers interfere with a critically important immune signaling pathway. There’s a possibility that correcting this defect may one day become part of a useful treatment for many types of cancer.” Lee is the senior author of the research, which will be published in the advance online version of Proceedings of the National Academy of Sciences on May 18.

Clues that the interferon pathway is important in fighting off cancers come from mouse models in which the pathway has been artificially disrupted. These animals develop spontaneous tumors at higher rates than normal animals with functional interferon signaling—showing that the immune system quashes many cancers in their infancy. Some viruses are also known to inhibit the interferon pathway.

“It’s a very dynamic interaction,” said Lee. “If the immune system is successful in stopping a developing cancer, we never know about it because no disease develops. If the cancer cell population overcomes the immune system, you get cancer.” In other words, physicians and patients see only the immune system’s defeats. This adds an additional hurdle to overcome for new cancer treatments called immunotherapies that are meant to work by stimulating the patient’s immune system to attack tumor cells.

Lee and his colleagues had previously shown that the interferon signaling pathway was compromised in melanoma patients. In the current study, the researchers investigated whether patients with two other types of cancer—breast and gastrointestinal—also showed the same defect. They isolated immune cells called lymphocytes in blood samples from patients with three types of cancers (32 breast cancer patients, 12 melanoma patients and 11 gastrointestinal cancer patients) as well as from 28 age-matched healthy patients.

They then compared the response of three classes of lymphocytes—B cells, T cells and NK cells—to exposure to interferons. They found that lymphocytes from breast cancer patients, as well as melanoma and gastrointestinal cancer patients, expressed significantly lower levels of interferon-responsive signaling molecules than did lymphocytes from healthy patients.

“They have a clear defect in the interferon signaling pathway,” said Lee. When the researchers looked more closely at the lymphocytes from breast cancer patients, they found that the defect was equally severe in samples from people with early- and late-stage cancers—indicating that the problem must arise soon after the cancer begins to develop—and that it was present regardless of whether the patient had ever been treated with chemotherapy. Finally, the researchers showed that the immune cells from the breast cancer patients responded less efficiently to external activation signals.

“It’s now looking like the interferon pathway may harbor a general immune defect in many types of cancers,” said Lee. He and his colleagues are working to pinpoint what exactly is going haywire in the pathway and why. They are also investigating whether the problems are likely to block the effectiveness of some of the newer immunotherapies that rely on the presence of a functional immune system.

“Whatever functional defect these immune cells have likely impacts the effectiveness of both active immunotherapy, like cancer vaccines, and passive immunotherapy, like cellular therapies,” said Lee. “If these forces are still at play in vivo, the patient’s immune response to these types of treatments will be blunted.”

Would you like to donate blood but are afraid of needles? The Stanford Blood Center is sponsoring a panel discussion at 7 p.m. May 21 to address one of the most elusive issues in blood donor recruitment: Fear. The panelists will explore different perspectives regarding the fear of medical procedures in general, and blood donation in particular.

The need for blood donations increases each year as hospitals grow larger, but the number of eligible donors stays the same. “Only 37 percent of the U.S. population is eligible to donate blood,” said center marketing manager John Williams. “In the Bay Area, only 3 percent actually donate. We are reaching out to those who haven’t come in because of a fear of the donation process.”

Panelists include:

• Medical school faculty members Wesley Alles, PhD; John Farquhar, MD; and Michelle Brown, PhD, who will discuss the scientific and psychological experience of fear and overcoming fear.
• Brennah Payne, an 11-year-old who was in a car accident at age 7, will walk attendees through the nine surgeries and multiple blood transfusions she underwent at Lucile Packard Children’s Hospital.
• Longtime donor Linda Johnson will talk about the importance of making donating a part of your life.
• An apprehensive potential donor, Daniel Chui, will share his thought process and make a decision about whether he will donate blood for the first time.
• Mary Hayes, training supervisor at the Stanford Blood Center, will explain the extensive program she administers to staff who perform blood-collection procedures.

A patient at Stanford Hospital who recently underwent a liver transplant needed 158 units of blood. “That means it took donations from 158 people from all over the Bay Area to save this patient,” said center spokesperson Brooke Krannich. “Many people are apprehensive about trying something new — especially something like giving blood. We hope to show our community that it isn’t as scary as they might think, and this is the best place to give because our staff are highly trained and donations go directly to patients like Brennah in local hospitals.”

HIV-positive patients who don’t seek medical attention until they have a serious AIDS-related condition can reduce their risk of death or other complications by half if they get antiretroviral treatment early on, according to a new multicenter trial led by researchers at the Stanford University School of Medicine.

The study results could lead to widespread changes in treatment for HIV patients, particularly those diagnosed at an advanced stage, experts say.

“Even in San Francisco, one of the first epicenters of HIV in the United States, we still find that many people still present late in the course of their illness with an opportunistic infection,” said Mitch Katz, MD, San Francisco’s director of health, who was not involved in the study. “This study shows that it is life-saving to treat those persons with antiretroviral drugs while they are still in the hospital. The results of this study will change practices throughout the world.”

Some 60,000 to 70,000 newly HIV-infected individuals are identified every year in the United States, according to recently revised figures from the federal Centers for Disease Control and Prevention. A growing number of these patients, particularly minorities, youth, injection-drug users and those in poor rural areas, are being diagnosed late in the disease process when they’ve already developed life-threatening conditions, said Andrew Zolopa, MD, associate professor of infectious diseases and geographic medicine at Stanford and first author of the study. When these patients come for treatment of these complications, doctors are often reluctant to give them anti-AIDS drugs at the same time, fearing the two therapies could interfere with one another.

“A lot of people wait, thinking, ‘Let’s get the patient out of acute crisis, and then we’ll deal with the underlying HIV infection later,’” said Zolopa. “But that answer is wrong. If we’re more aggressive with HIV drugs, we can reduce AIDS-related complications and death by 50 percent. It’s a substantial clinical benefit.”

The study was conducted by the AIDS Clinical Trials Group, the world’s largest clinical trial organization. Results will be published May 18 in the online journal PLoS-ONE.

William Powderly, MD, dean of medicine at the University College Dublin School of Medicine, said the study addresses one of the last, longstanding unknowns in the management of AIDS.

“Clinicians have long grappled with the question of whether or not early treatment with antiviral drugs will help people who come to the hospital with advanced infections, such as pneumonia,” said Powderly, MD, the study’s senior author. “The answer is clearly yes. Early antiviral treatment for HIV improves the clinical outcome, including the likelihood of surviving in the next few months. It probably does so by improving the immune system and therefore adds to the ability to resist these infections.”

The study findings, presented in abstract form at an earlier scientific meeting, are already starting to change clinical practices. The International AIDS Society, the CDC and the British AIDS Society all have adopted guidelines that recommend that early antiretroviral treatment be considered in patients with an opportunistic infection, Zolopa noted.

The study involved 262 patients at 39 sites across the United States, from Puerto Rico to Seattle. An additional 20 patients were enrolled in a hospital in Johannesburg, South Africa. Eighty-five percent of the patients were men whose median age was 28. They were an ethnically diverse group: 37 percent were black, 36 percent Hispanic, 23 percent white and 5 percent Asian.

The patients all had one or more opportunistic infection, with the most common ones being pneumocystis jirovecii pneumonia, cryptococcal meningitis and serious bacterial infections. Patients with tuberculosis were excluded from the study because it was unclear what the optimal antiviral treatment was for these patients, Zolopa said.

The patients, who were enrolled between May 2003 and August 2006, were separated into two groups: those who got antiretroviral treatment early and those for whom this treatment was delayed until their opportunistic infections had been dealt with. The patients were all offered antiretroviral drugs free of charge. The drugs for the study were supplied by Abbott Laboratories (lopinavir/ritonavir), Gilead Sciences (tenofovir and emtricitabine) and Bristol-Myers Squibb (stavudine).

The patients in the early intervention arm of the study were treated with ARVs within an average of 12 days, while those in the deferred group received the treatment within an average of 45 days after the start of treatment for the opportunistic infection. Among the patients treated early, there were 20 (14.2 percent) who died or developed another significant AIDS-related complication. That compared with 34 patients (24.1 percent) in the deferred group who died or suffered a new complication.

In addition, the patients in the early treatment group saw a much swifter recovery of their immune systems. The early group patients saw their T-cell counts, a measure of the immune cells destroyed by the AIDS virus, increase to more than 100 within four weeks. In the deferred treatment group, it took 12 weeks for the patients’ T cells to reach that same level, the researchers reported.

“I was quite impressed at how rapidly these T cells could rise in these patients,” Zolopa said. “By starting ARVs early you can effectively reduce the window of vulnerability where another AIDS-related complication could develop.”

Zolopa said there was no difference between the two sets of patients in their adherence to their prescribed regimens. One concern in treating patients with ARVs soon after being diagnosed with AIDS is that they might not stick to their treatments and could then develop drug resistance. But adherence did not prove to be an issue, he noted.

“Starting the therapies early didn’t scare people off,” he said.

According to Zolopa, the study results probably provide some guidance for patients in developing countries, though each country would have to determine its own strategy for initiating ARVs in patients with advanced AIDS.

“These results do have important implications across the globe,” he said.

Although the study did not include patients with tuberculosis, the most common AIDS-related complication among patients in sub-Saharan Africa, early ARV treatment has been shown in other, more recent studies to be of value in those patients with TB, Powderly said.

Zolopa said implementing the study findings could entail some logistical challenges, as hospitals will have to develop interdisciplinary teams, including pulmonary specialists, emergency physicians, pharmacists and others, in coordinating early treatment for these critically ill patients as they come into the system.

A vaccine against the H1N1 influenza strain, which has crossed over from pigs to people in recent months, probably won’t be available before this autumn. But ongoing research at the Stanford University School of Medicine promises to help public-health authorities come to grips with future influenza pandemics—and may prove to be useful against this one.

A common theme in this research is that it pays to look not just at the virus itself, but also to our responses, at all levels, to viral attack: how immune responses vary among individuals, what sorts of medical innovation could help to prevent pandemics entirely and how we should organize the collective public-health response to pandemics when they do occur.

“While it’s still too early to draw conclusions, so far the H1N1 outbreak has proved fairly mild, at least in the United States,” said Mark Davis, PhD, director of the Stanford Institute for Immunity, Transplantation and Infection. “The next one could be more devastating.” Even typical seasonal influenza strains kill some 36,000 Americans each year, he noted.

Davis and several Stanford colleagues have assembled a facility, called the Human Immune Monitoring Core, in which blood samples are subjected to thousands of assays—for immune cell counts, such as cells’ ability to respond to different types of stimuli, levels of circulating immunity-related proteins in the blood and more. (A key source of samples is a study of older vs. younger people’s response to the standard seasonal flu vaccine, led by Davis and Cornelia Dekker, MD, professor of pediatrics and medical director of the Stanford-Lucile Packard Children’s Hospital vaccine program.) The goal is to figure out how these myriad molecular and cellular measures vary with the quality of an individual’s responses to the vaccines, said Davis, who is also the Burt and Marion Avery Family Professor of microbiology and immunology.

“We’re trying to define, at the molecular and cellular levels, what a normal response looks like,” he said. “When you give people a flu vaccine, some respond vigorously, others not as much. We hope to find the parameters that predict who will respond well and who’s at risk.”

Davis said he thinks the expertise and data he and his colleagues are accumulating may also prove useful in guiding the development of future influenza vaccines. “We’ve tended to use vaccines based on what has worked historically and without knowing much about the way they interact with the immune system. They usually work, but sometimes they don’t. New vaccines are here, but which is best? We think we can help get the answer.”

The National Institutes of Health recently contacted Davis and asked him to propose—within 24 hours—additional projects that might relate to the H1N1 strain. He did, with the help of other Stanford colleagues, suggesting that “instead of looking only at vaccinated people, we can look at people who have actually contracted the H1N1 strain, to see how their molecular and cellular responses correlate with their overall ability to cope with the infection.”

When a new vaccine targeting the H1N1 strain is available, perhaps as early as this September, “we’ll be there monitoring responses to that, too,” Davis said.

Even if that vaccine does arrive on schedule, there’s no guarantee it will prevent future pandemics, and public-health authorities will have to remain vigilant. A couple of years ago, Nayer Khazeni, MD, an instructor in pulmonary & critical care medicine and an associate at Stanford’s Center for Health Policy, developed with colleagues a mathematical model of a pandemic influenza outbreak in a place like New York City, based on the H5N1 or “avian flu” virus that is still causing concern among national and global health authorities. The team included graduate student David Hutton of the School of Engineering’s department of management science and engineering, and Alan Garber, MD, PhD, and Douglas Owens, MD, both professors of medicine.

These researchers have since been adapting their model to predict both the course of the new H1N1 viral strain and how that course could be altered by various interventions, such as vaccination and antiviral drugs, Khazeni said. “We’re able to compare different interventions and ask: Will it be cost-effective? Will it save lives?”

One intervention Khazeni said deserves careful study is the use of surgical masks, which block relatively large droplets of mouth or nasal secretions, vs. so-called respirators, which are more sophisticated (and commensurately more expensive) masks with much smaller pore sizes, so that even some aerosols are blocked. “This is sort of mind-boggling when I tell people who don’t study influenza, but we don’t know how influenza is transmitted,” she said. “If it’s by large droplets, surgical masks might work; if via aerosols, the more expensive respirators might be more effective.” Khazeni and her Stanford co-investigators intend to compare the cost-effectiveness of the two types of masks.

Another area Khazeni is scrutinizing is the long-term use of antivirals as prophylactics. “Historically, most pandemic waves—peaks of infection in a given community—have lasted for about six to eight weeks. So, to be maximally effective for prevention, antivirals would also have to be given for six to eight weeks. But most clinical trials of prophylactic antiviral use have given the drugs only for several days.” To investigate long-term prophylaxis, Khazeni’s team has been conducting a meta-analysis: a mathematically rigorous teasing out of statistical and clinical significance (or the lack thereof) by pooling data from many trials whose outcomes, in individual trials, may have been too uncertain to draw firm conclusions about effectiveness and safety. Results of this analysis should be available fairly soon, she said.

Any large-scale influenza pandemic is going to leave hospitals short on a critical device: the ventilator, which assists breathing in instances of severe respiratory distress. Government studies have estimated a national shortage of almost 750,000 ventilators in the event of a serious influenza pandemic, said Matthew Callaghan, MD, a postdoctoral scholar in medicine who is affiliated with Stanford’s Biodesign Program, a joint venture between the schools of Engineering and Medicine. Yet standard hospital models cost from $30,000 to $60,000 apiece, he said. “Even the stripped-down, portable ventilators found in ambulances cost between $4,000 and $6,000 apiece.”

A Stanford team led by Callaghan—and including Joelle Faulkner, who is another biodesign fellow, medical student Dhruv Boddupalli and mechanical engineering graduate student William Bishop—has produced prototypes of a ventilator, relatively free of bells and whistles, that can be assembled from off-the-shelf components. “It is tailored for a specific indication, acute respiratory distress, and would sell for as little as $300 to $600 per unit,” Callaghan said. “We set out to create a device specifically made for stockpiling in the event of a pandemic. You don’t need the functionality of the $50,000 model,” he said. “It’s cheap enough that, we envision, every hospital would be able to stockpile hundreds of these machines.” They’d be disposable—one patient, one ventilator—with a shelf-life of about three years. The device, developed in part with funding from the Coulter Foundation and the National Collegiate Inventors and Innovators Alliance, is scheduled to go into animal testing (ironically, in pigs, whose lungs are similar to those of humans) in June.

Of course, the ideal is to have an effective enough vaccine and enough supplies of it so that no one will need ventilators. One challenge is that with a pandemic virus, where there has been no past human exposure, very high vaccine doses and a booster shot are required to induce an immune response. That in turn necessitates manufacturing huge amounts of vaccine material to cover an entire population for each new strain. Yet, Khazeni noted, current incarnations of the seasonal influenza vaccine don’t use any adjuvants—substances that, added to many other vaccines in use today, stimulate immune response in general and therefore make the vaccines more potent, regardless of the particular infectious agent they’re targeting.

During National Stroke Awareness Month in May HealthYes!, a mobile medical screening provider, is strongly encouraging Americans to follow the “3 R’s”– reduce risk, recognize symptoms and respond immediately. Following these steps could limit the number of Americans who die or are disabled each year by a stroke.

“The effects of a stroke can be permanent unless treated quickly because dead brain cells simply cannot be replaced,” said Douglas J. Fox, M.D., Executive Medical Director, NeuroTexas Institute at St. David’s HealthCare. “Getting treatment within one to two hours of the onset of symptoms helps resume blood flow moving to the brain and minimizes the risk of damage.”

A stroke, sometimes referred to as a “brain attack,” occurs when the blood flow to the brain is disrupted by a blood clot or a hemorrhage within the brain. Without a constant flow of blood and oxygen, piece by piece, the brain dies, sometimes permanently affecting body functions controlled by that particular portion of the brain. For example, a person could lose the use of an arm, leg or even the ability to speak as a direct result of a stroke.

HealthYes!™ screens for five life-threatening medical conditions including stroke. When screening for strokes, HealthYes! uses multiple ultrasound images of the right and left carotid arteries to help identify conditions affecting blood flow, blood flow velocities and plaque build-up within those arteries. According to The Centers for Disease Control and Prevention (CDC), 87 percent of all strokes occur due to clots that block arteries in the brain.

“Prevention remains key to reducing the risk of stroke. HealthYes! can accurately identify artery blockage which, in turn, improves the ability to identify at-risk individuals,” said Dale Wood, President, HealthYes! “This allows those who do have arterial blockage to quickly seek aggressive preventive intervention and treat their symptoms before a stroke occurs.”

In February 1976, a strain of H1N1 swine flu caused the death of one man and hospitalization of several others at Fort Dix military base. This strain of swine flu was confined to the military base. During March of the same year, however, a new strain of the virus developed which circulated throughout the United States causing illness and panic. By October 1976, all American citizens were urged to get a vaccination to combat the swine flu. Over 50 million Americans (about 30% of the population) received vaccinations from October to December of that year.

Edward Hall was vaccinated along with his wife in the ‘70’s. “There were millions of people who got those vaccinations,” says Hall. “I’m sure some are wondering if they have any protection against the 2009 strain of the virus. I know I am.”

According to the Center for Disease Control and Prevention, it is highly unlikely that the 1970’s immunization will combat the new strain of virus. They say that “the Federal Government and manufacturers have begun the process of developing a vaccine against this new virus.”

Jessica Rampton, biologist and Chief Science Officer at Uplift Nutrition, states, “Viruses mutate rapidly and while year to year variations may be minor, there can be significant differences every ten years or so and this new strain is said to be quite an unusual new genetic mix of virus. Unfortunately, a new vaccine could take up to 6 months to produce… and furthermore, vaccines may only partially reduce risk.”

Another viable approach may be for people to implement a self-health program to support and strengthen their immune systems. As well as being mindful of healthy diet and lifestyle, one can turn to immune boosting supplements to support and strengthen the body’s ability to fend off attacks from micro-organisms like viruses. Fortifying the body with health-promoting herbs, fruits and greens may help promote immunity health in the body.

Researchers at Stanford University’s School of Medicine today received a $5.8 million grant from the California Institute for Regenerative Medicine. Michael Longaker, MD, is the principal investigator on the five-year grant, which is focused on ways to stimulate existing adult stem cells to heal damaged nerves, bone, skin and cardiac muscle.

The grant was made as part of the institute’s Early Translational Research Awards, which are meant to move promising basic stem cell research from the laboratory into the clinic. It was one of 15 grants totaling $67.7 million that were awarded during a meeting of the institute’s 29-member governing board.

“With these Early Translational grants, CIRM has taken the first step in funding translational research that will be critical for the development of future therapies,” said CIRM president Alan Trounson in a prepared statement. “These grants are an important part of CIRM’s strategy to fund the best basic research and then bring the results of that work to patients.”

Longaker, who is the deputy director of Stanford’s Institute for Stem Cell Biology and Regenerative Medicine, and his colleagues plan to continue their ongoing study of a class of protein molecules called Wnts that mediate the natural response of adult stem cells to injury. The grant received the highest score of the 15 applications approved for funding, and reviewers were noted to be “uniformly enthusiastic” about the proposal.

“This approach takes advantage of the solution that nature itself developed for repairing damaged or diseased tissues,” Longaker wrote in the grant application, noting that it also bypasses immunological and ethical hurdles to using transplanted stem cells in human therapy because it would involve stimulating a patient’s own stem cells. “When utilizing this strategy, the goal of reaching clinical trials in human patients within five years becomes realistic.”

The Gallup-Healthways Well-Being Index (WBI), the largest and most comprehensive daily tracking survey of American health and well-being, showed no significant increase in the percentage of Americans reporting flu-related illness in April 2009. On any given day, between 1 to 4 percent of the adult population reports being sick with the flu. The April average was 2.1 percent, slightly less than the average during the same period a year ago.

The Gallup-Healthways Well-Being Index surveys a random sample of 1,000 adults each day, or roughly 30,000 interviews each month on a variety of topics related to health and well-being, making it one of the most accurate barometers of population health trends in existence. One of the questions asked daily is, “Were you sick with any of the following yesterday?” The question specifies four illnesses: the flu, a cold, a headache and allergies. The WBI does not specifically differentiate between flu strains. Given the current swine flu situation, these data provide a baseline for monitoring increases or decreases in the incidence of flu at both the population and community levels.

It is unlikely that the spread of swine flu in the United States will be so massive that it would move the percentages in these reports in and of itself. Each percentage of the adult population represents about 2.2 million people, so even tens of thousands of cases of swine flu would not by themselves have a major impact on national samples.

Still, widespread publicity about a disease such as swine flu no doubt will increase Americans’ focus on their health and symptoms. Thus, it is possible that those who in the past may have ignored symptoms will find themselves rushing to the doctor to have their symptoms diagnosed, and this could cause the self-reported incidence of flu to increase as a secondary byproduct of the swine flu situation. There has, however, been no increase in self-reports of flu in the last several days by WBI respondents.

Many people confuse flu symptoms with common-cold symptoms. Colds, at least as reported by average Americans, are significantly more prevalent than flu. The percentage of the adult population that reports having been “sick with a cold” on any given day throughout the year ranges from a little more than 2% to nearly 11%. As with flu, there is apparently predictable cyclicality. Colds are most commonly reported in the late fall and winter, and drop off significantly in the summer months.

There is a significant inverse correlation between age and reports of having been “sick with the flu yesterday” in the Gallup-Healthways data. These data are an aggregate of more than 110,000 interviews conducted so far in 2009, from Jan. 2 through April 27. Younger adults are most likely to report being sick with the flu, and the percentage drops fairly steadily with age. Incidence of flu among children and among teenagers aged 13 to 17 is not reflected in the data.

It is important to remember that these data reflect being “sick with the flu” and do not indicate mortality as a result of flu. It’s likely that the consequences of having the flu are much more significant among older people, even if the prevalence of the disease itself is lower. Additionally, older Americans who are so sick with flu that they are hospitalized would not be available for interviewing.