On November 13th, five colleagues and I released an open letter to The Lancet and editor Richard Horton about the PACE trial, which the journal published in 2011. The study’s reported findings–that cognitive behavior therapy and graded exercise therapy are effective treatments for chronic fatigue syndrome–have had enormous influence on clinical guidelines for the illness. Last October, Virology Blog published David Tuller’s investigative report on the PACE study’s indefensible methodological lapses. Citing these problems, we noted in the letter that “such flaws have no place in published research” and urged Dr. Horton to commission a fully independent review.
Although Dr. Horton’s office e-mailed that he would respond to our letter when he returned from “traveling,” it has now been almost three months. Dr. Horton has remained silent on the issue. Today, therefore, we are reposting the open letter and resending it to The Lancet and Dr. Horton, with the names of three dozen more leading scientists and clinicians, most of them well-known experts in the ME/CFS field.
We still hope and expect that Dr. Horton will address–rather than continue to ignore–these critical concerns about the PACE study.
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Dr. Richard Horton
The Lancet
125 London Wall
London, EC2Y 5AS, UK
Dear Dr. Horton:
In February, 2011, The Lancet published an article called “Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomized trial.” The article reported that two “rehabilitative” approaches, cognitive behavior therapy and graded exercise therapy, were effective in treating chronic fatigue syndrome, also known as myalgic encephalomyelitis, ME/CFS and CFS/ME. The study received international attention and has had widespread influence on research, treatment options and public attitudes.
The PACE study was an unblinded clinical trial with subjective primary outcomes, a design that requires strict vigilance in order to prevent the possibility of bias. Yet the study suffered from major flaws that have raised serious concerns about the validity, reliability and integrity of the findings. The patient and advocacy communities have known this for years, but a recent in-depth report on this site, which included statements from five of us, has brought the extent of the problems to the attention of a broader public. The PACE investigators have replied to many of the criticisms, but their responses have not addressed or answered key concerns.
The major flaws documented at length in the recent report include, but are not limited to, the following:
*The Lancet paper included an analysis in which the outcome thresholds for being “within the normal range” on the two primary measures of fatigue and physical function demonstrated worse health than the criteria for entry, which already indicated serious disability. In fact, 13 percent of the study participants were already “within the normal range” on one or both outcome measures at baseline, but the investigators did not disclose this salient fact in the Lancet paper. In an accompanying Lancet commentary, colleagues of the PACE team defined participants who met these expansive “normal ranges” as having achieved a “strict criterion for recovery.” The PACE authors reviewed this commentary before publication.
*During the trial, the authors published a newsletter for participants that included positive testimonials from earlier participants about the benefits of the “therapy” and “treatment.” The same newsletter included an article that cited the two rehabilitative interventions pioneered by the researchers and being tested in the PACE trial as having been recommended by a U.K. clinical guidelines committee “based on the best available evidence.” The newsletter did not mention that a key PACE investigator also served on the clinical guidelines committee. At the time of the newsletter, two hundred or more participants—about a third of the total sample–were still undergoing assessments.
*Mid-trial, the PACE investigators changed their protocol methods of assessing their primary outcome measures of fatigue and physical function. This is of particular concern in an unblinded trial like PACE, in which outcome trends are often apparent long before outcome data are seen. The investigators provided no sensitivity analyses to assess the impact of the changes and have refused requests to provide the results per the methods outlined in their protocol.
*The PACE investigators based their claims of treatment success solely on their subjective outcomes. In the Lancet paper, the results of a six-minute walking test—described in the protocol as “an objective measure of physical capacity”–did not support such claims, notwithstanding the minimal gains in one arm. In subsequent comments in another journal, the investigators dismissed the walking-test results as irrelevant, non-objective and fraught with limitations. All the other objective measures in PACE, presented in other journals, also failed. The results of one objective measure, the fitness step-test, were provided in a 2015 paper in The Lancet Psychiatry, but only in the form of a tiny graph. A request for the step-test data used to create the graph was rejected as “vexatious.”
*The investigators violated their promise in the PACE protocol to adhere to the Declaration of Helsinki, which mandates that prospective participants be “adequately informed” about researchers’ “possible conflicts of interest.” The main investigators have had financial and consulting relationships with disability insurance companies, advising them that rehabilitative therapies like those tested in PACE could help ME/CFS claimants get off benefits and back to work. They disclosed these insurance industry links in The Lancet but did not inform trial participants, contrary to their protocol commitment. This serious ethical breach raises concerns about whether the consent obtained from the 641 trial participants is legitimate.
Such flaws have no place in published research. This is of particular concern in the case of the PACE trial because of its significant impact on government policy, public health practice, clinical care, and decisions about disability insurance and other social benefits. Under the circumstances, it is incumbent upon The Lancet to address this matter as soon as possible.
We therefore urge The Lancet to seek an independent re-analysis of the individual-level PACE trial data, with appropriate sensitivity analyses, from highly respected reviewers with extensive expertise in statistics and study design. The reviewers should be from outside the U.K. and outside the domains of psychiatry and psychological medicine. They should also be completely independent of, and have no conflicts of interests involving, the PACE investigators and the funders of the trial.
Thank you very much for your quick attention to this matter.
Sincerely,
Ronald W. Davis, PhD
Professor of Biochemistry and Genetics
Stanford University
Jonathan C.W. Edwards, MD
Emeritus Professor of Medicine
University College London
Leonard A. Jason, PhD
Professor of Psychology
DePaul University
Bruce Levin, PhD
Professor of Biostatistics
Columbia University
Vincent R. Racaniello, PhD
Professor of Microbiology and Immunology
Columbia University
Arthur L. Reingold, MD
Professor of Epidemiology
University of California, Berkeley
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Dharam V. Ablashi, DVM, MS, Dip Bact
Scientific Director, HHV-6 Foundation
Former Senior Investigator
National Cancer Institute, NIH
Bethesda, Maryland
James N. Baraniuk, MD
Professor, Department of Medicine,
Georgetown University
Washington, D.C.
Lisa F. Barcellos, PhD, MPH
Professor of Epidemiology
School of Public Health
California Institute for Quantitative Biosciences
University of California
Berkeley, California
Lucinda Bateman, MD
Medical Director, Bateman Horne Center
Salt Lake City, Utah
David S. Bell, MD
Clinical Associate Professor of Pediatrics
State University of New York at Buffalo
Buffalo, New York
Alison C. Bested MD FRCPC
Clinical Associate Professor of Hematology
University of British Columbia
Vancouver, British Columbia, Canada
Gordon Broderick, PhD
Director, Clinical Systems Biology Group
Institute for Neuro Immune Medicine
Professor, Dept of Psychology and Neuroscience
College of Psychology
Nova Southeastern University
Miami, Florida
John Chia, MD
Clinician/Researcher
EV Med Research
Lomita, California
Lily Chu, MD, MSHS
Independent Researcher
San Francisco, California
Derek Enlander, MD, MRCS, LRCP
Attending Physician
Mount Sinai Medical Center, New York
ME CFS Center, Mount Sinai School of Medicine
New York, New York
Mary Ann Fletcher, PhD
Schemel Professor of Neuroimmune Medicine
College of Osteopathic Medicine
Nova Southeastern University
Professor Emeritus, University of Miami School of Medicine
Fort Lauderdale, Florida
Kenneth Friedman, PhD
Associate Professor of Pharmacology and Physiology (retired)
New Jersey Medical School
University of Medicine and Dentistry of NJ
Newark, New Jersey
David L. Kaufman, MD,
Medical Director
Open Medicine Institute
Mountain View, California
Nancy Klimas, MD
Professor and Chair, Department of Clinical Immunology
Director, Institute for Neuro-Immune Medicine
Nova Southeastern University
Director, GWI and ME/CFS Research, Miami VA Medical Center
Miami, Florida
Charles W. Lapp, MD
Director, Hunter-Hopkins Center
Assistant Consulting Professor at Duke University Medical Center
Charlotte, North Carolina
Susan Levine, MD
Clinician, Private Practice
New York, New York
Visiting Fellow, Cornell University
Ithaca, New York
Alan R. Light, PhD
Professor, Department of Anesthesiology and Department of Neurobiology and Anatomy
University of Utah
Salt Lake City, Utah
Sonya Marshall-Gradisnik, PhD
Professor and Co-Director
National Centre for Neuroimmunology and Emerging Diseases
Griffith University
Queensland, Australia
Peter G. Medveczky, MD
Professor, Department of Molecular Medicine, MDC 7
College of Medicine
University of South Florida
Tampa, Florida
Zaher Nahle, PhD, MPA
Vice President for Research and Scientific Programs
Solve ME/CFS Initiative
Los Angeles, California
James M. Oleske, MD, MPH
Francois-Xavier Bagnoud Professor of Pediatrics
Senator of RBHS Research Centers, Bureaus, and Institutes
Director, Division of Pediatrics Allergy, Immunology & Infectious Diseases
Department of Pediatrics
Rutgers – New Jersey Medical School
Newark, New Jersey
Richard N. Podell, M.D., MPH
Clinical Professor
Rutgers Robert Wood Johnson Medical School
New Brunswick, New Jersey
Charles Shepherd, MB, BS
Honorary Medical Adviser to the ME Association
London, United Kingdom
Christopher R. Snell, PhD
Scientific Director
WorkWell Foundation
Ripon, California
Nigel Speight, MA, MB, BChir, FRCP, FRCPCH, DCH
Pediatrician
County Durham, United Kingdom
Donald Staines, MBBS MPH FAFPHM FAFOEM
Professor and Co-Director
National Centre for Neuroimmunology and Emerging Diseases
Griffith University
Queensland, Australia
Philip B. Stark, PhD
Professor of Statistics
University of California, Berkeley
Berkeley, California
Eleanor Stein, MD FRCP(C)
Assistant Clinical Professor
University of Calgary
Calgary, Alberta, Canada
John Swartzberg, MD
Clinical Professor Emeritus
School of Public Health
University of California, Berkeley
Berkeley, California
Ronald G. Tompkins, MD, ScD
Summer M Redstone Professor of Surgery
Harvard University
Boston, Massachusetts
Rosemary Underhill, MB BS.
Physician, Independent Researcher
Palm Coast, Florida
Dr Rosamund Vallings MNZM, MB BS
General Practitioner
Auckland, New Zealand
Michael VanElzakker, PhD
Research Fellow, Psychiatric Neuroscience Division
Harvard Medical School & Massachusetts General Hospital
Boston, Massachusetts
William Weir, FRCP
Infectious Disease Consultant
London, England
Marcie Zinn, PhD
Research Consultant in Experimental Neuropsychology, qEEG/LORETA, Medical/Psychological Statistics
NeuroCognitive Research Institute, Chicago
Center for Community Research
DePaul University
Chicago, Illinois
Mark Zinn, MM
Research consultant in experimental electrophysiology
Center for Community Research
DePaul University
Chicago, Illinois