Take the Walking Test, if You Dare!

Summarized by Robert W. Griffith, MD
June 5, 2006

Summary

Doctors find that a simple walking test can predict future health problems for people over 70 years of age.

Introduction

By now, everyone over 50 knows that aerobic fitness is associated with a longer life, but the majority of baby-boomers still avoid the task of getting down to exercising. Maybe a new report from the University of Pittsburgh, published in the Journal of the American Medical Association will help convince them. The investigators looked at the ability of 70-years-olds to walk 400 meters (437.5 yards, about a quarter of a mile), which they called the log-distance corridor walk, and correlated their results with subsequent mortality. Here's a summary of their findings.

What was done

The study enrolled 3075 people aged 70 to 79 years; 52% of them were women, and 42% were black. They were recruited from Medicare beneficiaries living in Pittsburgh, Pennsylvania and Memphis, Tennessee. They reported no difficulty in walking a quarter of a mile, climbing a flight of stairs, or performing activities of daily living (ADLs).

For the walking test, participants were asked to walk 400 meters in a hallway, doing ten 20-meter laps, with standard encouragement given at each lap. They were to "walk as quickly as you can, without running, at a pace you can maintain." Anyone with abnormal vital signs or ECG, recent cardiac symptoms or surgery, chest pain, shortage of breath, or fainting was excused. If persistent fast heartbeat occurred during the walk, or there were leg or chest pains, feeling of faintness, or shortage of breath, they were expected to stop walking. Assessments consisted of the ability to complete the 400 meters walk, the time taken, and blood pressure and heart rate recovery at the end of the walk.Health outcomes - cardiovascular disease, and reasons for disability of mobility - were determined by phone interviews every six months and checks of hospital records, death certificates and so on. The follow-up period averaged 5 years.

What was found

Out of 2680 people who were eligible for the test, 86% completed the walk. During the follow-up 351 died, 308 had cardiovascular disease events (heart attack, severe angina, cardiac death, or stroke), and 509 had developed mobility disability. Inability to complete the walk was associated with mobility limitation in 44% of the participants.

Those who completed the test were classified into four groups (quartiles) according to the time they took: 201-289 seconds, 290-322 seconds, 323-361 seconds, and 362-942 seconds. In the lowest quartile (those who took more than 362 seconds (~6 minutes) were at least 3 times more likely to die in the next 5 years than those in the fastest group (less than 290 seconds, or 4.8 minutes). The total walking time taken was relevant for all the outcomes measured. Each minute of total time was associated with a 29% higher rate of mortality, a 20% higher rate of cardiovascular disease, and a 52% higher rate of mobility limitation and disability.

The fastest group contained slightly younger participants, more men, more Caucasians, had a lower body mass index (BMI), and were more active physically.

What these results mean

The investigators see this test as a possible substitute for treadmill testing as a predictor of future health problems in older adults; less than a third of the participants were able to manage a treadmill. There's no doubt that such a test can be useful for reinforcing the need for physical activity and weight control in older people. The threat of increased likelihood of mobility limitation or disability may be all that's needed to get someone to start a walking program or an improved nutrition program. It may even have more influence than a warning of increased mortality!

Source

• Association of long-distance corridor walk performance with mortality, cardiovascular disease, mobility limitation, and disability. AB. Newman, EM. Simonsick, BL. Naydeck,  et al., JAMA, 2006, vol. 295, pp. 2018--2026

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