Background: The endurance shuttle walk test (ESWT) is a standardized externally controlled constant paced field test for the assessment of endurance capacity in chronic lung disease. The ESWT has been advocated as a simple, acceptable, repeatable and responsive outcome measure for COPD patients undergoing pulmonary rehabilitation, but has not been formally compared with the more commonly used field walking test, the six-minute walk (6MW). We aimed to determine: 1) the responsiveness of the ESWT in COPD patients attending a hospital-based pulmonary rehabilitation programme, and 2) to compare the responsiveness of the ESWT with the 6MW.
Methods: Consecutive COPD patients, referred for a standard 8 week pulmonary rehabilitation programme, were recruited. Outcome parameters studied at baseline and completion of rehabilitation programme (8 weeks) included spirometric lung volumes, resting oxygen saturation, breathlessness scored pre and post exercise (modified Borg dyspnoea score), 6MW, ESWT, health-related quality of life (Chronic Respiratory Questionnaire) and Hospital Anxiety and Depression (HAD) scale. The incremental shuttle was employed to predict VO2 peak; 85% VO2 peak was used to determine the walk speed for the ESWT.
Results: Twenty stable COPD patients (11 male), mean (SD), age 71, (9) FEV1 0.95 (0.51), resting SpO2 95% (2) 6MW distance (m) 351 (104) and ESWT distance (m) 313 (193) were studied. Three patients did not complete their rehabilitation programme. Following rehabilitation, there were significant improvements in 6MW, ESWT, total CRQ and anxiety domain (HAD). The 6MW distance increased by 17% (47 m 95%CI 3, 90), while the ESWT increased by 92% (302 m 95%CI 104, 501).
Conclusion: The ESWT is a simple, acceptable and highly responsive outcome measure for COPD patients undergoing a pulmonary rehabilitation programme. The ESWT has potential advantages in that it may be more responsive than the 6MW.