NIH initiatives driven by public health burden

NIH has taken the lead in implementing strategies to lessen this burden in terms of disease and economic costs, explained Elias A. Zerhouni, MD, director of NIH since 2002. He delivered one of two keynote addresses at the Association for Research in Vision and Ophthalmology annual meeting.

"In the 21st century, we have to intervene before symptoms appear and preserve normal function for as long as possible," said Dr. Zerhouni, who had been the executive vice dean of Johns Hopkins University School of Medicine and chairman of the department of radiology and radiological science before his NIH appointment.

"The expenditures on health over the next 10 years are expected to double from $1.6 trillion today to $3 trillion," Dr. Zerhouni explained. "Many policymakers wonder whether this is sustainable and whether our industry is sustainable over the long run."

For the last 30 years, there has been a shift in the types of diseases that practitioners are treating. The U.S. population has been experiencing more chronic diseases that can lead to disability.

According to the Centers for Disease Control and Prevention (CDC) statistics, the greatest concerns for disability over the next 25 years are musculoskeletal diseases, vision loss, and hearing loss, seen in the aging population. Emerging diseases, such as obesity, are also adding to the public health burden.

Other NIH priorities include understanding the persistence of health disparities to influence policymakers and the new priority of biodefense, Dr. Zerhouni said.

Physicians should be familiar with the three phases of disease development:

Dr. Zerhouni showed an S-shaped curve on a graph to demonstrate how the three phases of a disease can occur. At some point the disease burden starts to rise rapidly to enter the intolerable phase and more costly treatment interventions are tried.

"We tend to intervene when there is a disease that has been diagnosed," Dr. Zerhouni explained. "This is usually done in the late tolerable phase and the early intolerable phase.

"Every time you intervene, you can reduce the burden for a while," he said.

Every time an intervention is introduced, the cost associated with that intervention can be measured. As the disease progresses, more expensive interventions are necessary to bring the patient back to the tolerable phase of disease.

For example, high blood pressure, a known risk factor for acquiring heart disease, is discovered and the patient is told to exercise more daily. The cost at this preclinical phase of disease is relatively low.

However, if the physician does not suggest exercise or the patient does not heed the physician's advice, some inexpensive drugs may be initiated. Again, if the prescription is not given and the disease progresses, more expensive drugs may have to be considered. The patient may experience more symptoms of heart disease and may have to undergo a stress test and be monitored more frequently at a cost of about $1,000.