Pulmonary Rehabilitation and Improvement in Exercise Capacity Improve Survival in COPD
"While the short- and medium-term benefits of pulmonary rehabilitation in COPD patients have been shown, its effects on survival have not been studied," said lead author Johanna Williams, MSc, a researcher at the Department of Respiratory Medicine at the University Hospitals of Leicester NHS Trust. "Our analysis shows that completion of pulmonary rehabilitation and a higher level of response in exercise capacity is associated with a significant survival advantage in COPD patients."
The results will be presented at the ATS 2012 International Conference in San Francisco.
Of 1,615 patients with COPD in the observational cohort study, 55.4% completed pulmonary rehabilitation. Subjects who completed pulmonary rehabilitation (n = 895), compared with those who did not (n = 720), had significantly higher mean incremental shuttle walking test (ISWT) scores at baseline. Kaplan Meier (KM) survival analysis revealed that there was a statistically significant survival advantage for those who completed rehabilitation when compared with those who didn't complete (p<0.001 by the log rank test).
"These results should be interpreted with caution however," said Ms. Williams "as improved survival is unlikely to be simply a result of completion of rehabilitation but also probably reflects that the sickest patients may be unable to complete and/or may have more co-morbidities so are more likely to die sooner".
For those patients that did complete rehabilitation, 56.3 percent improved by more than 48m, the minimum clinically important difference (MCID) for the ISWT, and were considered responders. After adjustment for a number of prognostic factors including baseline ISWT, survival analysis showed that these responders had a significantly improved survival compared with non-responders (p<0.001 by the log rank test). "It should be remembered however that it is currently unknown whether other factors (possibly genetic) may influence a better training response and thus may be also associated with improved survival" said Ms. Williams.
"Our study shows that pulmonary rehabilitation and the magnitude of response in exercise tolerance following pulmonary rehabilitation in patients with COPD is associated not only with short-term improvements, but possibly also with improved survival," said Ms. Williams. "COPD patients should be encouraged to exercise."