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Brief aan

de hoofdredakteur

van de Lancet

m.b.t. kritiek op PACE trial

afgewezen voor publikatie






You win some, you loose some...



De brief van dr. Maes, Cort Johnson en ondergetekende aan de hoofredakteur van de Lancet,

met feitelijk onderbouwde kritiek op de PACE-trail, is afgewezen voor publicatie.


De hoofdredakteur noemt in een toelichting vijf redenen waarom brieven geweigerd worden:

de brief is te laat, verwijst naar nieuw onderzoek, bevat "case reports", is te lang (250

woorden) of bevat meer dan 5 referenties, of is een herhaling van wat reeds gesteld werd.


Zo niet, laat de redaktie ons weten, is de brief geweigerd,

omdat de redaktie te veel kwalititatief-hoogwaardige reakties ontvangen heeft...


Aangezien de brief niet om één van de bovengenoemde redenen geweigerd kan zijn,

is de konklusie dat er veel "kwalititatief-hoogwaardige" reakties binnengekomen zijn.

Als publikatie van die reacties van anderen in de toekomst uitblijft,

dan weet U hoe laat het is wat betreft het wetenschappelijke karakter van de Lancet.



Voor meer achtergronden bij onze brief, klik op onderstaande afbeelding:








Letter to the Editor,


Cognitive behaviour therapy/graded exercise therapy

is not an effective treatment

for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.


Frank NM Twisk, Michael Maes, Cort Johnson.



According to White et al. (1)

"either cognitive behaviour therapy (CBT) or

graded exercise therapy (GET),

when added to specialist medical care (SMC),

are effective treatments for chronic fatigue syndrome (CFS)".


The size of this effect is however very moderate,

while 60% reported they did not see

a positive result in Global Impression of Health Scale benefit.


The Work and Social Adjustment scale indicated

the average CBT/GET patient was still

at the borderline of being 'very severely impaired'.

The conclusion is that

these treatments cannot be considered to be effective (1) or curative (2).


More importantly, due to the selection criteria,

the participants cannot be considered to be CFS patients,

e.g. 47% met criteria for psychiatric disorders,

while the two subjective measures fatigue and physical function

are largely insufficient to establish recovery:

cut-off scores on these measures

do not correspond with a CFS diagnosis.



an improvement in "fatigue"

is not reflected by a significant objective improvement,

e.g. in physical activity (3).


When looking at the only objective measure (1),

i.e., meters walked in 6 minutes

(CBT: 354; GET: 379; compared to 349 for SMC after treatment),

CBT and GET hardly qualify as "moderately effective".


As recently has been confirmed (4),

CBT and GET are not effective and even potentially harmful

for many ME/CFS patients (5).


According to (1)

non-serious adverse events for CBT (89%) and GET (93%)

are very common.


Therefore the claim that

"CBT and GET can safely be added to SMC" (1)

cannot be substantiated.





  1. White PD, Goldsmith KA, Johnson AL, Potts L, Walwyn R, DeCesare JC, et al. Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial. The Lancet 2011 Feb 17. doi: 10.1016/S0140-6736(11)60096-2.
  2. Wessely, S. Chronic fatigue syndrome - trials and tribulations. JAMA 2001; 286; 1378-9. doi: 10.1001/jama.286.11.1378.
  3. Wiborg JF, Knoop H, Stulemeijer M, Prins JB, Bleijenberg G. How does cognitive behaviour therapy reduce fatigue in patients with chronic fatigue syndrome? The role of physical activity. Psychol Med 2010; 40: 1-7. doi: 10.1007/s10067-009-1339-0.
  4. Núñez M, Fernández-Solà J, Nuñez E, Fernández-Huerta JM, Godás-Sieso T, Gomez-Gil E. Health-related quality of life in patients with chronic fatigue syndrome: group cognitive behavioural therapy and graded exercise versus usual treatment. A randomised controlled trial with 1 year of follow-up. Clin Rheumatol 2011 Jan 15. doi: 10.1007/s10067-010-1677-y.
  5. Twisk FNM, Maes M. A review on cognitive behavorial therapy (CBT) and graded exercise therapy (GET) in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS): CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients. Neuro Endocrinol Lett 2009; 30: 284-99.