In their paper on recovery rates in the PACE trial, White et al. (Reference White, Goldsmith, Johnson, Chalder and Sharpe2013) acknowledge that ‘objective measures of physical activity have been found previously to correlate poorly with self-reported outcomes’. Yet, there is no attempt to utilize the Six Minute Walking Test results. The best results were a mean of 379 metres walked in the graded exercise therapy condition, a gain of 67 metres in 52 weeks, 35 metres more than the specialist medical care (SMC)-only group (White et al. Reference White, Goldsmith, Johnson, Potts, Walwyn, DeCesare, Baber, Burgess, Clark, Cox, Bavinton, Angus, Murphy, Murphy, O'Dowd, Wilks, McCrone, Chalder and Sharpe2011). The cognitive behaviour therapy group showed no improvement compared with the SMC group. The distance of 379 metres is exceeded by patients listed for lung transplantation (Kadikar et al. Reference Kadikar, Maurer and Kesten1997) and by older patients with chronic heart failure (Lipkin et al. Reference Lipkin, Scriven, Crake and Poole-Wilson1986). Given the recognized problem with self-reported outcomes, reliance solely on such measures leaves open the question of the validity of the recovery criteria of PACE.
Declaration of Interest
None.