Six-minute walk distance in patients with severe end-stage COPD: association with survival after inpatient pulmonary rehabilitation.


PURPOSE To evaluate the relationship between the 6-minute walk distance (6MWD) and survival in a cohort of patients with severe end-stage chronic obstructive pulmonary disease (COPD) who received inpatient pulmonary rehabilitation (IPR) from 1995 to 2007. METHODS We retrospectively analyzed 815 patients with severe end-stage COPD who received IPR. 6MWDs before and after IPR (pre-6MWD, post-6MWD) were compared to assess whether 6MWD was significantly changed after IPR. The Kaplan-Meier survival curves were constructed to show the relationship between survival and 6MWD. The age- and or comorbidities-adjusted Cox proportional hazard model was applied to assess association between the survival and the pre-6MWD, post-6MWD, or difference in 6MWD from the pre-6MWD to post-6MWD (Delta6MWD). RESULTS Baseline demographics demonstrated a median age 74.0 years, mostly women (60.1%), and white (89.9%) patients with significant comorbid diseases who were most recently hospitalized in acute care facilities (95.1%). IPR significantly increased the 6MWD (mean distance change: 86.4 m; 95% confidence interval [CI], 81.5-91.3 m). Pre-6MWD was not significantly associated with survival. However, post-6MWD was significantly associated with age- and comorbidity-adjusted survival (post-6MWD hazard ratio = 1.336; 95% CI, 1.232-1.449 [post-6MWD x m relative to post-6MWD 2x m]), and Delta6MWD was also significantly associated with age-, comorbidities-, and pre-6MWD-adjusted survival (Delta6MWD hazard ratio = 1.337; 95% CI, 1.227-1.457 [Delta6MWD x m relative to Delta6MWD 2x m]). CONCLUSIONS In patients with severe end-stage COPD, IPR significantly improved 6MWD, and the post-6MWD and Delta6MWD were positively associated with the length of survival.

DOI: 10.1097/HCR.0b013e3181c565e4

Cite this paper

@article{Enfield2010SixminuteWD, title={Six-minute walk distance in patients with severe end-stage COPD: association with survival after inpatient pulmonary rehabilitation.}, author={Kyle B. Enfield and Sally Gammon and Jennifer Floyd and Cassandra Falt and James T. Patrie and Thomas A. E. Platts-Mills and Jonathon Dean Truwit and Yun Michael Shim}, journal={Journal of cardiopulmonary rehabilitation and prevention}, year={2010}, volume={30 3}, pages={195-202} }