In a recent Article Michael Sharpe and colleagues report on findings of a follow-up study of the PACE trial of proposed rehabilitative interventions for chronic fatigue syndrome: graded exercise therapy (GET) and cognitive behavioural therapy (CBT). Their main finding is that the beneficial effects of CBT and GET were maintained at follow-up (median: 2 to 5 years).
Both CBT and GET have been qualified by the PACE trial investigators as “moderately effective treatments”. However, looking at the data of the follow-up study and other PACE trial studies CBT and GET do not qualify as rehabilitative therapies for chronic fatigue syndrome or myalgic encephalomyelitis, as defined by the London criteria.
First, the PACE trial investigated the effects of CBT and GET in chronic fatigue, as defined by the Oxford criteria, not in chronic fatigue syndrome, let alone myalgic encephalomyelitis, as defined by the Ramsay criteria.
The Oxford criteria have been criticised often. For that reason open quote “consensus groups and researchers should consider retiring the Oxford case definition” end quote.
Second, the positive effect of CBT and GET in subjective measures, fatigue and physical functioning, cannot be qualified as sufficient. Mean short form-36 physical functioning scores in the CBT group (62·2) and the GET group (59·8) at follow-up were below the inclusion cutoff score for the PACE trial ( less than or equal to 65) and far below the objective for recovery as defined in the PACE protocol (greater than or equal to 85). The mean fatigue scores in the CBT group (18·4) and GET group (19·1) were above subnormal (<18)4 and far above the entry criterion for the PACE trial (>12, recalculated) and the recovery criterion in the PACE protocol (≤6).
Third, the PACE trial follow-up study concluded that outcomes with specialist medical care alone or adaptive pacing therapy (APT) were similar to CBT and GET at follow-up. The authors suggest that open quote ”it is important to note that many of the participants had received additional treatment for CFS since completing the trial”, end quote. Looking at the data, 23 (20%) of the patients in the specialist medical care arm received an adequate number of sessions (n=10) of CBT after the PACE trial and 14 (12%) received GET, while 20 (17%) of the patients in the APT group received CBT and 7 (6%) received GET afterwards. This finding implies that the vast majority of patients improved subjectively by specialist medical care and APT to the same level as by CBT and GET, without any additional therapies, including CBT and GET, or by other therapies.
Finally, looking at subjective outcomes at follow-up and objective outcomes in earlier studies, such as physical fitness, return to employment, social welfare benefits, and health-care usage, CBT and GET, like specialist medical care and APT, cannot be qualified as effective.
In conclusion, CBT and GET are moderately effective in subjective terms in chronic fatigue, but looking at the patients studied and the (subjective and objective) outcomes of the PACE trial, CBT and GET do not meet the requirements for rehabilitative or effective therapies for chronic fatigue syndrome, let alone myalgic encephalomyelitis.