Every silver lining has a cloud. Or so it seems while scanning threatening newspaper stories that look to the future of our aging society. Social Security is going to go belly up! Medicare is going to bankrupt the country! Our health care system is going to implode!
The ominous headlines have a way of obscuring a rather sunny number that's driving all these crises: human life expectancy. A century ago, average U.S. life expectancy at birth was 47 years. Today, it is 78. And many Americans are staying spry well into their 80s and even 90s. This is bad news?
Not to Linda Fried. "We are in the midst of a profound demographic revolution," says the professor of Medicine, Epidemiology, and Health Policy and Management. "This country is going from one in which only 4 percent of the population was over 65 to one in which a fifth will be over 65 soon."
Such numbers are without precedent in human history. And it's happening in the span of a single, short century. So is it really a surprise that they add up to a need for revolutionary change in the practice of public health?
Shaping that change is what Fried's work is all about at the Center on Aging and Health, a center of excellence sponsored jointly by the Johns Hopkins schools of Public Health, Nursing and Medicine. Through their research in aging, Fried and colleagues are grappling with issues that will have powerful implications in the years to come. Can we remake society in ways that better value and engage older adults? Reinvent the way we deliver medical care to those most in need?
"This is a field that needs transformative thinking and leadership," Fried says. "The underbelly of what's going on here is really exciting and interesting. The discussions we need to generate go to the heart of our concept about who we are as a society and who we're going to become as a society. We can't afford to have people keep looking at this in that gloom-and-doom way."
Basic Training
One concept at the core of these discussions is "compression of morbidity." Developed nearly three decades ago by James Fries, a Stanford professor and Hopkins Medicine alumnus, it shifts the bottom-line focus in the field away from standard mortality measures and toward the idea that success is best defined as keeping older adults healthy for as long a time as possible—and unhealthy for as short a time as possible.
Early on, the idea was controversial. Many scientists at the time regarded declining mental functioning in older adults as inevitable and irreversible. But recent studies have shown time and again that older adults can learn to think faster, remember better and reason more efficiently. Work by George Rebok, a professor of Mental Health at the Bloomberg School, has raised hopes that cognitive training interventions can promote good health outcomes and delay or prevent the onset of Alzheimer's and other dementias.
Older adults "have much more plasticity in the cognitive system than we used to think," Rebok says. "It's not just a matter of everyone is going to go downhill as they get older and there's nothing to be done about it."
Starting in the mid-1990s, Rebok embarked on the largest clinical investigation ever undertaken of such interventions. Dubbed ACTIVE (Advanced Cognitive Training for Independent and Vital Elderly), this study tracked the progress of nearly 3,000 participants who landed either in a control group or in one of three different training programs.
One program targeted memory skills by teaching mnemonic strategies (such as visualization and association) along with verbal techniques focused on word lists and blocks of text. A second program aimed to boost reasoning skills by working on participants' abilities to find patterns in series of letters or words. The third program focused on speed-of-processing skills and involved challenging visual searches complicated by asking participants to tackle two searches simultaneously.
By 2030, the number of Americans over 65 will swell to 70.3 million — 20 percent of the total population. —Experience Corps
Each training regimen consisted of 10 hour-long sessions. A subset of study participants also attended "booster" classes at one- and three-year intervals. Across all classes, ACTIVE was targeted to cognitive skills in a generalized sense, with no more than 10 percent of class time devoted to working on real-world problems like memorizing a grocery list or reading a bus schedule.
Initial results were published in JAMA in December 2006 and landed soon thereafter in dozens of newspapers around the country, as well as at the top of JAMA's online list of most-requested papers. All three training programs succeeded in boosting the cognitive skill they targeted. More importantly, the study found that gains in all three training categories persisted reasonably well for at least five years when compared with the control group.
Rebok refers to ACTIVE as a "low-dose intervention." Up until now, research efforts have focused more on pharmacological interventions or biological treatments (such as vitamin E and hormone therapy) than on approaches as straightforward as ACTIVE.
The most tantalizing of Rebok's findings came in an attempt to gauge whether the cognitive gains helped participants lead fuller, healthier and more independent lives. The study tracked evaluations by subjects of their ability to handle various "Instrumental Activities of Daily Living." At the end of five years, all three of the intervention groups reported less difficulty with those activities than the control group, with the results for reasoning-skills training group being most impressive.
"This was the first study that has been able to show that connection," says Rebok, PhD. "Probably more than anything else, that's what's got everybody really excited."
Alzheimer's disease has surpassed diabetes and pneumonia as the fifth-leading cause of death for people over 65. —National Institute on Aging
ACTIVE is an ongoing study. Rebok plans to test participants again at 10 years after intervention. He is also working to push this cognitive-training model to another level. Would a cross-training regimen that aimed to improve all three capabilities succeed? What about a hybrid training program that mixed boosting cognitive skills with training in specific independent living skills, such as medication management or meal preparation?
"The basic theoretical model here is that these three cognitive abilities underlay most everyday activities and should generalize to those activities," Rebok says. Study participants were tested on activities such as looking up a number in a phone book, finding and retrieving a particular item on a grocery-store shelf, and responding to signage in a simulated driving test.
"This cognitive kind of training is a lot more realistic and achievable than an intervention that tries to target a thousand different everyday activities," Rebok says.
Another issue on the horizon is what form these interventions may take in the future. Cognitive-training websites like Happy Neuron and Train My Brain are up and running already. Rebok himself is working with a group of investigators funded by the National Institute on Aging to develop a Web-based "Memory University®" that will deliver mnemonic training classes, information about the nature of memory, and memory assessments targeted toward older, independently living adults.
"The accessibility of the Internet provides an excellent means by which to provide practice opportunities and periodic booster sessions for older adults," Rebok says. "This is going to be a real question for the future. How do you develop scientifically sound programs that are accessible and that are enjoyable and that people will stick with for a long period of time?"
