Inaccuracy of Estimating Peak Work Rate from Six-Minute Walk Distance in Patients with COPD

M.J.H. Sillen*, J.H. Vercoulen, A.J. van 't Hul, P.H.C. Klijn, E.F.M. Wouters, D. van Ranst, J.B. Peters, A.R.J. van Keimpema, F.M.E. Franssen, H.J.A.M. Otten, J. Molema, J.J. Jansen, M.A. Spruit

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Abstract Introduction. The cardiopulmonary exercise test (CPET) and the 6-minute walk test (6MWT) are used to prescribe the appropriate training load for cycling and walking exercise in patients with chronic obstructive pulmonary disease (COPD). The primary aims were: (i) to compare estimated peak work rate (Wpeakestimated) derived from six existing Wpeak regression equations with actual peak work rate (Wpeakactual); and (ii) to derive a new Wpeak regression equation using six-minute walk distance (6MWD) and conventional outcome measures in COPD patients. Methods. In 2906 patients with COPD, existing Wpeak regression equations were used to estimate Wpeak using 6MWD and a new equation was derived after a stepwise multiple regression analysis. Results. The 6 existing Wpeak regression equations were inaccurate to predict Wpeakactual in 82% of the COPD patients. The new Wpeak regression equation differed less between Wpeakestimated and Wpeakactual compared to existing models. Still, in 74% of COPD patients Wpeakestimated and Wpeakactual differed more than (+/-) 5 watts. Conclusion. In conclusion, estimating peak work load from 6MWD in COPD is inaccurate. We recommend assessment of Wpeak using CPET during pre-rehabilitation assessment in addition to 6MWT.
Original languageEnglish
Pages (from-to)281-288
JournalCopd-Journal of Chronic Obstructive Pulmonary Disease
Volume9
Issue number3
DOIs
Publication statusPublished - 1 Jan 2012

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