medwireNews: The sit-to-stand (STS) test can predict 2-year mortality in patients with chronic obstructive pulmonary disease (COPD), say researchers.
Patients who did not survive beyond 2 years performed significantly fewer repetitions of the test during 1 minute than patients who survived (mean 11.8 vs 19.5), such that every five additional repetitions were associated with a 42% decrease in the risk for death.
Handgrip strength was also associated with reduced mortality at 2 years (hazard ratio=0.84) in the prospective cohort study.
They authors say that exercise capacity is one of the strongest predictors for mortality in COPD but is not routinely measured in practice, possibly due to lack of staff or other resources deemed necessary to perform more complex exercise tests.
"The STS test may close an important gap in the evaluation of exercise capacity and the prognosis of COPD patients across practice settings," Milo Puhan (Johns Hopkins Bloomberg School of Medicine, Baltimore, Maryland, USA) and team write in the European Respiratory Journal.
The STS test involves the patient repeatedly sitting and standing as many times as possible in 1 minute. As such, it may be a more practical means of measuring exercise capacity in routine practice than other methods, such as the 6-minute-walk distance .
The study involved just over 400 patients with COPD being treated in Dutch and Swiss primary care centers. The mean age of patients at enrollment was 67.3 years, 57% were male, and 63.8% had Global Initiative for Chronic Obstructive Lung Disease stage II, 21.8% stage III, and 14.4% stage IV COPD.
In addition to mortality, STS and handgrip strength were correlated with health-related quality of life assessed using the Chronic Respiratory Questionnaire. Neither test was found to be predictive of COPD exacerbations, but there was a low rate of exacerbations during the study (49.9% of patients had no exacerbations).
"The STS test was a stronger predictor of mortality than [% predicted forced expiratory volume in 1 second], dyspnea, or the use of inhaled drugs," the researchers report.
"Its simplicity makes it an ideal test [not only] for primary, but also for acute care settings," they add.
While the handgrip test was also somewhat predictive of mortality, it does not provide as much useful information, the team suggests. It might, however, serve as a useful first test to identify patients who could require more extensive exercise testing, they conclude.
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