The main trial recovery criteria, described by White et al. (Reference White, Goldsmith, Johnson, Chalder and Sharpe2013), allow participants with SF-36 physical function scores of ⩾60 to be classed as recovered if, for example, their ‘main symptom’ is no longer fatigue.

In terms of clinical interpretation, such a threshold is problematic because it is in conflict with how the condition itself is defined. For example, it indicates worse impairment than the PACE Trial entry criteria threshold of ⩽65 (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) and the diagnostic threshold of ⩽70 used by Reeves et al. (Reference Reeves, Wagner, Nisenbaum, Jones, Gurbaxani, Solomon, Papanicolaou, Unger, Vernon and Heim2005) to indicate ‘substantial’ physical impairment.

Further, a score of ⩽65 has been used to indicate severely impaired physical function in similar patient groups (Stulemeijer et al. Reference Stulemeijer, de Jong, Fiselier, Hoogveld and Bleijenberg2004; van't Leven et al. Reference van't Leven, Zielhuis, van der Meer, Verbeek and Bleijenberg2009).