Doctors can measure how fast elderly patients walk to help estimate their life expectancy and determine medical care, according to a research analysis.
At age 75, 10-year survival for the fastest men in nine clinical trials was 87 percent compared with 19 percent for the slowest, said researchers led by Stephanie Studenski, a professor of medicine at the University of Pittsburgh, in a statement. For the fastest women that age, such survival was 91 percent compared with 35 percent for the slowest.
Life expectancy varies and shouldn’t be based on age and sex alone, the scientists said. Measuring gait speed may become a tool for predicting patients’ survival and help doctors tailor care, as when deciding to order screening for prostate cancer, Studenski said.
“Health in late life is imperfectly captured by the list of medical conditions you have,” said Studenski, in a telephone interview on Dec. 31. “Walking speed is a simple way to summarize the capacity and function of many of your body’s systems.”
The analysis by Studenski and 18 coauthors was released today by the Journal of the American Medical Association.
Paces ranged from about 1 mile an hour (1.6 kilometers an hour) to more than 3.5 miles an hour in the studies, Studenski said. For every 0.2 miles an hour that walking speed increased, survival rose about 12 percent.
Walking requires energy and movement control, while demanding work from the heart, lungs, skeleton and other parts of the body, the researchers said. Walking speed can be tested with a stopwatch, from a standing start, over distances as short as 13 feet, according to the report.
“Slowing gait may reflect both damaged systems and a high energy cost of walking,” the scientists wrote.
The researchers analyzed nine clinical trials that involved 34,485 community-dwelling adults, ages 65 year or older, who were followed for six to 21 years. Overall 10-year survival was almost 60 percent, while the five-year survival rate was 85 percent.
Predicting survival according to a combination of age, gender and walking speed was as accurate as figures based on age, gender, chronic conditions, smoking history, blood pressure, body mass index and hospitalization, the researchers said.
Estimating Health Status
“Gait speed is a marker of well being,” said Matteo Cesari, the author of journal editorial on the subject, in an e-mail on Dec. 30. “By assessing gait speed in older persons, a physician will be able to immediately obtain an estimate of the patient’s overall health status in terms of expected years to be lived,” said Cesari, who is a geriatrician working as a consultant with Universita Campus Bio-Medico in Rome.
The findings will help doctors decide how to proceed with care, Studenski said.
For instance, prostate cancer screening is limited to men whose life expectancy is at least 10 years. The screening is generally stopped around age 75, as many people that age, even if they develop prostate cancer, are likely to die of another cause before the cancer can become deadly.
Using walking speed, a doctor now may be able to judge which men 75 or older may have a longer life expectancy and should continue the screenings, she said.
“We need better measures to help us individualize care planning for older people,” Studenski said.
The research was funded by the National Institutes of Health.