Medical researchers in Baltimore are launching what is considered the most extensive study ever attempted into the effects of aging on women's health.
The five-year study, which will involve 1,000 women 65 and over in Baltimore and Baltimore County, will try to determine which chronic illnesses are most responsible for causing disabilities as women age, and how disabilities can be lessened or prevented.
The diseases include arthritis, heart disease, stroke, osteoporosis, cancer, diabetes and hearing and vision impairments. The diseases are well known, but their impact on the nation's elderly -- especially women -- has not been well studied, according to scientists.
"It would seem that we should know this," Dr. Linda Fried of the Johns Hopkins School of Medicine, said yesterday. "It almost seems self-obvious. But amazingly enough, we do not [know it] in any rigorous fashion."
Supported by a $7.9 million grant from the National Institute on Aging, the study is the work of 30 scientists from the Johns Hopkins School of Hygiene and Public Health, the Johns Hopkins School of Medicine and the aging institute.
In part, the research has been spurred by dramatic population shifts that will force society to deal as never before with the difficulties encountered by aging Americans.
For example, the slice of the America made up of people over age 65 has ballooned -- from 4 percent of the population in 1900 to 11 percent today. Thirty years from now, baby boomers will tip the scales further to the point where seniors represent one-fifth of the population.
Also, some long-held assumptions about aging have been upset in recent years, causing scientists to question the expectation that most elderly people will have to enter nursing homes or become dependent on their families.
"We used to assume that cardiovascular diseases were an inevitable part of aging," Dr. Fried said. "Now, we know it's not the case. It's more likely to show up as people get older, but it's preventable."
Also, doctors do not understand why diseases cause some people to have difficulty taking care of themselves while others with the same diseases remain active, she said. If the study can answer that question, scientists might be able to prevent disabilities or ease their impact.
Dr. Fried said the research team wanted to focus on women because they live longer then men and suffer longer with disabling illnesses. While women make up 52 percent of those over 65, they are two-thirds of the population over 85.
Volunteers will not be accepted into the study. To get a true cross-section, researchers are randomly selecting women from lists of Medicare recipients. Initially, some 5,400 women will be screened, and from that group 1,000 women will be chosen to take part.
At the outset, participants will get a comprehensive physical examination. That will be followed by interviews every six months over the course of three years to assess changes in physical function. It could be five years before results are published.
The researchers, who sent out their initial letters to potential participants last week, will begin visiting the women Thursday.
Participants will receive a token payment for their time.