'Walking distance' test an accurate indicator of disease severity in patients with COPD

May 16, 2011

The six-minute walking distance test (6MWD), a test that measures a patient's ability to tolerate exercise and physical activity, is an effective tool for understanding disease severity in patients with chronic obstructive pulmonary disease (COPD), according to a three-year global study of patients with COPD sponsored by drug manufacturer GlaxoSmithKline.

The study will be presented at the ATS 2011 International Conference in Denver.

"We found that baseline 6MWD was predictive of with an acute COPD exacerbation, was relatively stable in milder COPD, and has a steady rate of decline in patients with severe disease," said study author Martijn Spruit, PhD, scientific advisor and research leader at the Centre of Expertise for Chronic (CIRO+) in Horn, the Netherlands. "This confirms prior observations that the results of the 6MWD are related to the risk of death in patients with COPD, and that the test is a useful tool in understanding in patients with COPD."

Researchers studied 2,110 patients with moderate to severe COPD who underwent a supervised 6MWD at study enrollment to provide a baseline value and annually for 3 years. Death and exacerbation-related hospitalization were recorded.

During 3 years of observation, 200 patients died and 650 were hospitalized for . and exacerbation-related hospitalization were higher in COPD patients as baseline 6MWD decreased. Researchers found that a 6MWD threshold of 357 meters was optimal to predict increased risk of hospitalization; while a 6MWD threshold of 334 meters was optimal to predict an increased risk of death. The mean rate of deterioration of the 6MWD was 5.7 meters per year and was primarily limited by the ability of the patient to breathe easily.

"Exercise tolerance is an important clinical aspect of COPD which can be easily and reliably measured with the 6MWD test," Dr. Spruit said. "These data confirm the power of the 6MWD to identify subsets of the COPD population at higher risk of exacerbation-related hospitalization or death.

"The ability to group COPD patients according to their functional status disease severity should enable healthcare providers to better tailor therapy for their patients and optimize use of medical resources," he added. "Patient grouping is also useful for those designing interventional studies in COPD; for example, if the aim of an intervention were to reduce the rate of exacerbation related admission, then a study can be designed by including primarily patients at higher risk of that outcome."

Dr. Spruit also noted that the 6MWD test offers benefits over a more traditional test of COPD disease severity, the FEV1 (forced expiratory volume in the first second) which measures a patient's ability to forcefully exhale air in one second. "The FEV1 has limitations as a marker of disease severity in COPD because it fails to capture systemic manifestations of the disease," he said. "This study was designed to determine if the 6MWD could be an additional measure of disease severity, and the results confirmed that it can."

Explore further: Concurrent chemotherapy, proton therapy improves survival in patients with advanced lung cancer

Related Stories

Concurrent chemotherapy, proton therapy improves survival in patients with advanced lung cancer

July 20, 2017
For patients with advanced, inoperable stage 3 lung cancer, concurrent chemotherapy and the specialized radiation treatment, proton therapy, offers improved survival compared to historical data for standard of care, according ...

Shedding light on an emerging infectious disease

July 20, 2017
It lives in the lining of blood vessels and is transmitted to people mostly by fleas or ticks or lice, causing an array of diseases in both humans and animals.

Discovery could lead to better results for patients undergoing radiation

July 19, 2017
More than half of cancer patients undergo radiotherapy, in which high doses of radiation are aimed at diseased tissue to kill cancer cells. But due to a phenomenon known as radiation-induced bystander effect (RIBE), in which ...

Less invasive treatment for blocked artery in the leg is safe, review finds

July 20, 2017
Researchers found in a review of data from three large studies that a minimally invasive treatment to treat peripheral artery disease offers a safe alternative to standard surgery.

Low-cost drugs package saves lives of people starting HIV treatment late

July 20, 2017
Treating people who start HIV treatment late with a package of low-cost drugs to prevent serious infections saves three lives for every 100 people treated, according to the findings of a trial led by the Medical Research ...

New study says PPIs do not cause dementia

July 20, 2017
Several studies have reported associations between proton-pump inhibitor (PPI) use and dementia. New research published on July 18 in Gastroenterology, the official journal of the American Gastroenterological Association ...

Recommended for you

Google searches can be used to track dengue in underdeveloped countries

July 20, 2017
An analytical tool that combines Google search data with government-provided clinical data can quickly and accurately track dengue fever in less-developed countries, according to new research published in PLOS Computational ...

MRSA emerged years before methicillin was even discovered

July 19, 2017
Methicillin resistant Staphylococcus aureus (MRSA) emerged long before the introduction of the antibiotic methicillin into clinical practice, according to a study published in the open access journal Genome Biology. It was ...

New test distinguishes Zika from similar viral infections

July 18, 2017
A new test is the best-to-date in differentiating Zika virus infections from infections caused by similar viruses. The antibody-based assay, developed by researchers at UC Berkeley and Humabs BioMed, a private biotechnology ...

'Superbugs' study reveals complex picture of E. coli bloodstream infections

July 18, 2017
The first large-scale genetic study of Escherichia coli (E. coli) cultured from patients with bloodstream infections in England showed that drug resistant 'superbugs' are not always out-competing other strains. Research by ...

Ebola virus can persist in monkeys that survived disease, even after symptoms disappear

July 17, 2017
Ebola virus infection can be detected in rhesus monkeys that survive the disease and no longer show symptoms, according to research published by Army scientists in today's online edition of the journal Nature Microbiology. ...

Mountain gorillas have herpes virus similar to that found in humans

July 13, 2017
Scientists from the University of California, Davis, have detected a herpes virus in wild mountain gorillas that is very similar to the Epstein-Barr virus in humans, according to a study published today in the journal Scientific ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.