Past views of the future: The tricky art of medical forecasting
■ Predictions can prompt action that prevents a particular future from coming true or can become a goal or even a self-fulfilling prophesy. Regardless, the future rarely unfolds as planned.
By Victoria Stagg Elliott — Posted Aug. 1, 2005
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To forecast what is yet to come. To advance the art of prediction. These are concepts that consistently capture the imagination of both experts and popular culture.
Media headlines often detail such expectations and their focus is frequently health-related -- whether it involves long-term projections of public health indicators, emerging health risks or medical technologies on the horizon.
"People like to hear about the future," said Peter Bishop, PhD, chair of the masters program in studies of the future at the University of Houston-Clear Lake. "The consideration of the future as an intellectual pursuit and a thing to talk about actually has become more common and more fashionable for people in all walks of life."
But while predictions are common, analysis of what actually happened -- applying accountability -- is less so. What follows are five medicine-related predictions made in the past 40 years. Each offers a specific view of how the present day could have turned out, as well as what actually happened.
In February 1962, Reader's Digest predicted that by 2002, "Doctors will spend more time preventing disease than curing it."
How on target was this soothsaying? Experts say that medicine, in many respects, has moved in this general direction. In 1962, the annual physical was strictly the purview of the rich. Insurance rarely covered preventive services. And many screening tests common today didn't exist.
"There's no question that doctors spend more of their time focused on disease prevention," said Carolyn M. Clancy, MD, director of the Agency for Healthcare Research and Quality. "In 1962, everything was about sick care."
Provision of preventive services is supported by several American Medical Association policies, but quantifying a growing emphasis on disease prevention is also a matter of definition. Most agree that prevention encompasses vaccinations and counseling to promote healthy lifestyles -- aspects that are now a staple of modern medical practice. But disagreement centers on whether preventive care continues to occur once a patient is diagnosed with a condition. Is prescribing pharmacological treatment and providing lifestyle counseling to lower cholesterol considered to be treatment of hypercholesterolemia, prevention of a heart attack or both?
"If you take prevention to mean that we are going to keep people from getting diabetes, hypertension or hyperlipidemia, one could argue that we have absolutely failed," said John Sattenspiel, MD, a family physician from Salem, Ore. "If you look at prevention as preventing the adverse consequences of those diseases, then in fact, you could argue that at least 50% or more of our time is spent preventing long-term consequences from those chronic diseases."
Still, many physicians say significant barriers to fulfilling this prophesy continue to exist, including reimbursement issues and a shortage of time.
"Both patients and doctors feel caught in a time crunch," Dr. Clancy said. "But my prediction for today is that this will change."
"During the next 60 years, if the present trends continue, more than 1 million U.S. children now of school age will die of lung cancer before reaching the age of 70." That's what Lester Breslow, MD, MPH, ScD, then chief of the Division of Preventive Medical Services at the California State Dept. of Health, told Science Digest in November 1963.
Dr. Breslow made his prediction because, during the previous 60 years, lung cancer had gone from being a rare disease to one that killed more than 40,000 people annually. He calculated that if the rate of increase continued, the impact among this cohort of school-age children would be significant.
In the past four decades, though, the trendline he was charting shifted because of significant anti-smoking efforts. Lung cancer deaths started to decrease in the early 1990s, when the oldest of Dr. Breslow's cohorts should have started dying.
This change happened with minimal improvements in lung cancer-related medical care and survivorship.
"We're very fortunate in that it's not going to come true," said Dr. Breslow, a dean emeritus at the University of California, Los Angeles School of Public Health. "I would estimate now that substantially less than half that number will actually die of lung cancer."
Smoking cessation experts say, though, that Dr. Breslow might have been more on target than he gives himself credit for. Though death rates per 100,000 have been heading downward, the actual number of lung cancer mortalities still averages more than 160,000 deaths per year. There is also the fact that Dr. Breslow's 60-year timeline is not yet complete.
"He did a very remarkable calculation that horrifically came true, but I suggest that the prediction is an understatement," said Alan Blum, MD, director of the University of Alabama's Center for the Study of Tobacco and Society in Tuscaloosa.
Contraception for men and women
According to the Jan. 14, 1974, issue of U.S. News & World Report, women in 1994 would be able to "have a birth-control capsule implanted that will prevent conception for more than three years. Men could receive an injection every few months to keep them sterile."
This prediction turned out to be only about half right.
Norplant, the name of a form of five-year contraception for women involving six implantable silicone rods containing levonorgestrel, was first approved by the Food and Drug Administration in 1990 and was manufactured by Wyeth Pharmaceuticals. It's no longer available in the United States, primarily because of regulatory and liability issues, although it still has the agency's OK. Experts expect Implanon, a single implantable rod which last for three years, to be approved later this year. Implanon is manufactured by Organon, a division of Akzo Nobel headquartered in the Netherlands.
"We had Norplant, but it became embroiled in litigation," said Vanessa Cullins, MD, MPH, vice-president for medical affairs at the Planned Parenthood Federation of America. "We anticipate that Implanon will be available by the first or second quarter of 2006."
But while the prediction for women's contraception has been somewhat fulfilled, the other half has not. Several trials of hormonal birth control for men have been conducted since this prediction was made, and a handful are currently under way, including a large trial in Europe combining an injectable, long-acting testosterone with implantable progestogen. It is expected to conclude by December.
The big discovery thus far, however, has been that stopping male's daily production of millions of sperm is far more difficult than reining in a woman's one egg per month. "The male system is not meant to shut down and start back up easily," said Mitchell Creinin, MD, director of family planning at the University of Pittsburgh. "It takes a long time to get the sperm counts really low."
Swine flu flap
In March 1976, then-President Gerald Ford announced the "very real possibility" of a swine flu pandemic in the fall and launched the largest immunization campaign ever to prevent it.
This effort began to go south almost as soon as it was unveiled. Critics charged that the initiative was more connected to Ford's re-election efforts than public health science. Some vaccine had to be discarded because it didn't have the right antigens. Distribution to states was erratic. Insurance companies initially refused to cover manufacturers for vaccine-related adverse events. And the government ended up paying billions to people who developed Guillain-Barré syndrome.
Most crucially, the pandemic never came.
In some ways, the scientists and public health officials who advised Ford were in a no-win situation. Data seemed to point toward an impending epidemic. If one had emerged and no one had been vaccinated, society would have been in an uproar.
"What if an epidemic had happened?" asked Edwin D. Kilbourne, MD, who was part of Ford's advisory committee and is now a emeritus professor of microbiology at New York Medical College. "Given the same circumstances, I'd do the same thing again. This was a noble effort in public health."
Public health experts who observed the effort say that the initial decision to prepare for an impending pandemic was probably sound. Critics do question, however, why the situation wasn't periodically reassessed and the vaccination effort put on hold when it appeared that a pandemic was not quite imminent.
"What we needed to commit to was growing the eggs and being prepared," said Harvey V. Fineberg, MD, PhD, president of the Institute of Medicine and co-author of The Epidemic that Never Was, which analyzed the incident. "It wasn't prudent to announce at the beginning that we were going to vaccinate every man, woman and child in the country."
And perhaps some lessons were learned. Flu watchers are currently focused on the avian influenza outbreaks in Asia but are avoiding time-dated predictions.
In April 1984, then-Secretary of Health and Human Services Margaret Heckler made public the discovery of HIV and mentioned the possibility of a vaccine within two years.
This prediction has been widely misinterpreted to mean that there would be an actual vaccine available by 1986.
Heckler did not return calls, but news reports at the time indicate that what she actually said was as follows: "We hope to have such a vaccine ready for testing in approximately two years."
This prediction actually came true. The first vaccine candidate did make it to human trials in Africa in 1986. More than 80 others have been tested over the years since, although none successfully. Most experts say that, although Heckler's statements were perceived as being too optimistic, they were in line with what many scientists at the time thought was possible, primarily because no one had yet determined the difficulties that would be involved.
"She was right," said Jose Esparaza, MD, PhD, senior adviser on HIV vaccines at the Bill and Melinda Gates Foundation. "We all thought once the etiology of AIDS was discovered as a virus that a vaccine would be much easier than developing anti-viral drugs."
But after dealing with numerous predictions, deadlines and goals, those concerned with this issue have, for the most part, given up on predicting when and no one expects a successful vaccine any time soon. For example, Bill Gates, who funds a significant amount of this work through his foundation, earlier this year offered to eat his hat if a vaccine was discovered within the decade.
"Twenty years of research has made us more humble," Dr. Esparaza said. Work continues, and more than $600 million is expected to be invested in the effort this year.