Trial By Error: CBT and Irritable Bowel Syndrome

By David Tuller, DrPH

Had things gone as planned, the PACE trial should have been able to serve as proof that so-called medically unexplained symptoms (MUS)—in this case what the investigators referred to as chronic fatigue syndrome–could be successfully treated with psychological and behavioral therapies. The Lancet published the first PACE results, which reported benefits from cognitive behavioural therapy and graded exercise therapy, in early 2011. The timing dovetailed with the National Health Service’s expansion of a program called Improving Access to Psychological Therapies (IAPT).

Launched in England in 2008 to increase links between medical care and mental health services for those identified as suffering from depression and anxiety disorders, IAPT’s mandate next expanded to include other groups of patients, specifically those suffering from either long-term conditions, such as cancer, and from conditions identified as part of the MUS category. Many academic promoters of IAPT are colleagues of key PACE investigators. They are also fellow proponents of the CBT/GET paradigm for the illness, or cluster of illnesses, variously referred to as CFS, myalgic encephomyelitis, ME/CFS and CFS/ME.

Unfortunately for these folks, many segments of the international scientific community have rejected the PACE findings after public debate over the trial’s many documented missteps. In 2017, the US Centers for Disease Control and Prevention dropped its recommendations for CBT and GET after having already removed references to PACE from its website. Two years ago, BMC Psychology published a widely read paper rebutting the main PACE claims, based on raw trial data that were released only after a patient waged a lengthy battle for access under the freedom-of-information law. (I was a co-author of that paper.) Such developments have made it challenging to cite PACE as authoritative support for IAPT expansion. 

Not to worry! Those in favor of IAPT expansion are busy demonstrating that their preferred approach can address other kinds of MUS. Last fall, Lancet Gasteroenterology and Hepatology published a 24-month follow-up study of a clinical trial of CBT for irritable bowel syndrome (IBS), another condition lumped into the MUS category under the IAPT framework. The 12-month results of the study–called Assessing Cognitive behavioural Therapy for IBS, or ACTIB–were published earlier last year in Gut, a BMJ journal. While the investigators did not engage in some of the unusual methodological and ethical lapses documented in PACE, they nonetheless failed to create a compelling case for these CBT interventions.

The study included 558 participants with “refractory” IBS symptoms, defined as “ongoing symptoms after 12 months despite [the patient] being offered appropriate medications and lifestyle advice.” The investigators randomized them to three groups, with all receiving “treatment-as-usual” (TAU)—in other words, the standard care that had failed to resolve their complaints. Participants in two of the groups also received CBT–in one group through telephone sessions with a therapist, and in the other through a lower-intensity web-based program involving a lesser amount of therapist contact.

In subjective questionnaire responses, both CBT groups showed more improvement than the TAU-only group. That trend was sustained, to a lesser degree, in the 24-month follow-up. The investigators concluded that “increasing access to CBT for IBS could achieve long-term patient benefit.”

Let’s stipulate that stress reduction, however achieved, is generally a positive goal and a benefit to health. If the biochemical correlates of stress make people worse over the long-term no matter what their state of health or sickness, then strategies that might lower or minimize stress, including possibly CBT and other forms of psychotherapy, could easily lead to bonafide reports of improvements.

The IBS trial, like PACE and related studies, was unblinded and relied on self-reported outcomes. As has been argued repeatedly in the PACE debate, this study design creates a significant possibility of generating misleading results due to bias, even more so when a therapeutic relationship between clinician and patient is involved. Since it is difficult if not impossible to accurately measure the extent of such bias in any particular study with these characteristics, findings should be interpreted with caution. Investigators in the IBS field obviously confront a deficit of reliable biomarkers. But objective indicators such as a reduction in health care visits or fewer days off from work–vetted by official records–could support the argument that self-reported changes in symptoms are genuine and not an artifact of bias.

It is especially important to keep this factor in mind when the reported benefits are relatively small, such as those in this study. One of the two primary outcomes, for example, was the IBS Symptom Severity Scale,* a 500-point instrument based on patients’ answers to five questions about the intensity and frequency of their symptoms—abdominal pain, bloating, etc. Scores of less than 75 represent normal bowel function, with increasing numbers representing mild, moderate and severe symptoms. A change of 50 points or more on the scale is considered clinically significant. *[In this paragraph, I had mistakenly identified the instrument as the  “Severe Severity Scale” instead of the “Symptom Severity Scale.”]

Of the 70% of participants who supplied data at 12 months and the 58% who did so at 24 months, more individuals in the CBT arms than in the TAU arm had reductions in their scores of at least 50 points. But their experience tells us nothing about the final results of the significant minority that did not provide outcome data. Perhaps participants who found the whole exercise to be a waste of time, or worse, were less willing to provide follow-up data, either at the 12-month or 24-month point.

With an “intention-to-treat” analysis designed to account for missing data, the investigators compared the means of the severity scale results in the three arms. At 12 months, the mean score was lower for both CBT interventions than for TAU—61.6 points lower for telephone-delivered CBT and 35.2 points for web-based CBT. The first number is a bit over the 50-point threshold for what is considered a clinically significant change, the second a bit under. At 24 months, the respective mean scores in the two groups were 40.5 and 12.9 lower than the TAU score–less than 50 points in both cases. (In fact, the 24-month finding for web-based CBT was not statistically significant.) In other words, at both 12 months and 24 months, the reported benefits of CBT over TAU on this scale could be considered modest at best.

These reported improvements would seem to fall within the range that might be expected from the potential bias inherent in this study’s design. When some trial participants know they are getting something extra and other trial participants know they are not getting something extra, and both groups know the something extra is supposed to improve their health, it isn’t surprising that afterwards those who got something extra could be more likely to report improved health than those who got nothing extra.

But perhaps anything extra would do the trick, even more so if it involved contact with a therapist and/or web-based engagement and entertainment. Perhaps an intervention of streaming Harry Potter movies and discussing quidditch strategy with a phone therapist who alternated between the voices of Hermione and Hagrid would have a similarly beneficial effect as CBT– especially when compared to getting nothing. We just don’t know.

In this case, the researchers did not seek to craft a control group whose experience would simulate the intensity or frequency of the CBT interventions. As awful as PACE was, at least the adaptive pacing therapy arm paralleled the CBT/GET arms in terms of possible therapist contact and interaction, if not in the content. The IBS study contained no comparable control group—just people receiving regular care, which had already proven ineffective. These participants were offered the opportunity to access the web-based program after the first 12 months, although without any clinical support. This arm was thus randomized to what was essentially a “waiting list” condition—a frequent phenomenon in psychological studies.

As often happens in CBT studies, the intervention was adapted to the circumstances, making it harder to determine what aspect, if any, produced an effect. In this case, the CBT included advice on “developing stable healthy eating patterns,” per the Gut paper. In an illness like IBS, it is conceivable that sustained guidance on food and diet alone could lead to improved digestion and an easing of symptoms, but the study did not feature a comparison arm focused solely on that sort of intervention. Perhaps the reported improvements, if real, had more to do with suggestions about “healthy eating patterns” than with other elements of the CBT.

In presenting the findings, the Gut article noted that “psychological therapies and particularly face-to-face cognitive–behavioural therapy (CBT) can reduce symptom scores and improve quality of life by targeting unhelpful beliefs and coping behaviours.” In the context of this research, “reduce symptom scores” sounds about right, given that reducing symptom scores in a study prone to bias is not necessarily synonymous with actually reducing symptoms. In any event, a Cochrane review of psychological therapies for IBS, one of the cited references for the statement about symptom-reduction and improved quality-of-life from psychological therapies, questioned whether the reported benefits were meaningful.

The Cochrane review concluded the following: ”Psychological interventions may be slightly superior to usual care or waiting list control conditions at the end of treatment although the clinical significance of this is debatable. Except for a single study, these therapies are not superior to placebo and the sustainability of their effect is questionable.”

As with research into the CBT/GET treatment paradigm, leading members of the UK academic and medical establishments have produced an IBS study that has generated data of limited value while undoubtedly costing a lot of money. Major public health policy should ideally not be based on findings from open-label trials relying solely on self-reported outcomes, even more so when therapeutic relationships are involved and when there is no adequate control group. In this case, the investigators have documented the following: Compared to offering IBS patients nothing, offering them something leads to a few changes in how they answer questionnaires. Perhaps that represents some genuine improvement; perhaps not. It is hard to tell from the study.

 

 

Comments on this entry are closed.

  • Dr Ellen Goudsmit 24 January 2020, 1:35 pm

    Read todays BMJ on further problems with blinding before you write more things that illustrates your lack of knowledge. BRW for readers not obsessed with blinding, you can’t blind a hip op either. Pain is a subjective outcome. Be realistic.

  • David Tuller 24 January 2020, 1:53 pm

    Ellen, there’s really no need for you to be insulting to make a point. I’ve seen the new BMJ study about blinding/non-blinding. The authors themselves suggest many limitations and say these findings need to be backed up by subsequent work. It also contradicts previous work by the same group of authors. Concerns about open-label trials with solely subjective outcomes still stands.

  • Wendy Boutilier 24 January 2020, 2:23 pm

    Between 3 percent and 20 percent of Americans experience irritable bowel syndrome (IBS) symptoms. … IBS is also known as spastic colon, irritable colon, mucous colitis, and spastic colitis. It is a separate condition from inflammatory bowel disease and isn’t related …
    I have no idea why the Psychiatric Collaborative want to take a painful syndrome and include it in MUS, but I’m not surprised.

  • jimells 24 January 2020, 3:20 pm

    There is as much evidence that thinking the wrong thoughts causes IBS as there is evidence that thinking the wrong thoughts causes stomach ulcers, that is, none whatsoever.

    But that doesn’t matter as long as most medical research is really just marketing financed by the public.

    In all the years I’ve had gut problems, no doctor has ever asked me about these symptoms or made any attempt to treat them. My gut works mostly OK at the moment, but I had to work out treatments and what not to eat on my own using PubMed and Sci-Hub.

    I know that physicians are good for something but I have yet to work out what that is for me personally. For ME and all the various secondary symptoms I have, doctors have nothing except $20 pills for migraine attacks.

    Now the doctor is telling me that I have chronic renal insufficiency. So what is the treatment for that? Nothing!! Just the usual “lose weight, exercise more, stop smoking, treat hypertension, drink more liquids” that we are lectured about for every chronic illness. Exactly none of those generic recommendations apply to me, so all the doctor can tell me is, “Come back in six months to see if you’re still alive”.

    All the while the medical industry sucks up 15% of the entire economy of the US and life expectancy keeps dropping…

  • TT 25 January 2020, 5:44 am

    As with FND, IBS is often actually a symptom, or set of symptoms of a poorly understood biomedical condition, rare or common.

    So, for example, the dysmotility (autonomic and dryness combined) of an underestimated and undiagnosed autoimmune disease such as Sjögren’s, can present as IBS prior to the onset of more classic symptoms. Same applies to the more common Hypothyroidism and also Diabetes.

    However, by the time a doctor has pronounced that these symptoms are non structural, therefore given an IBS diagnosis, the sufferer might well have decided that going to a GP to talk about their poo problem again, is both humiliating and unhelpful. They may then decide not to “doctor bother” about other newer symptoms – but to instead just manage these as best they can.

    For example an older woman next to me on an acute ward was diagnosed with advanced bowel cancer within my hearing. She asked the very serious sounding doctor who was giving her this news, “so you’re telling me that the problem that’s made me unable to eat my morning roll without needing to run straight to the toilet, is actually this tumour, rather than the irritable bowel that my GPs have been telling me it is for a few years?”.

    CBT may be useful for those with chronic biomedical conditions, even the progressive ones, in helping us to focus on the positives where possible. Personally I don’t know this yet because there’s a year long waiting list for this ACT service, delivered by a few clinical psychologists in my area of Scotland.

    But IBS is a holding bay diagnosis and I for one wouldn’t be able to get anything out of an ‘evidenced based treatment‘ involving talking about distraction techniques and other stuff if I was still rushing for the holding bay toilet at regular intervals.

  • Lady Shambles 25 January 2020, 6:56 am

    What a shame this slushy ‘science’ wastes so much money. IBS might well be the consequence of a range of different disorders, but at least some people are trying to unravel it at the biological level which makes far more sense. This is one paper which appears to tease out a segment of people with IBS (about 1/6 of the IBS population possibly) who illustrate a maternal inheritance bias…. as far as I know inherited bias like this can’t be somatised 😉 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4071137/

    Why have the lessons wrt helicobacter pylori not been learned?: that patients do not somatise their symptoms… the symptoms are real and have a biological underpinning. It really is time to put together a piece of research asking why so many seemingly (‘supposed to be’ at any rate) intelligent people believe that diseases can be explained by the mind and therefore treated by changing thought patterns. Get to the ‘bottom’ of that one and we might be able to prevent wasting money and energy on future fruitless navel gazing at wandering wombs.

  • Katherine A Kearns 27 January 2020, 9:52 am

    For anyone with IBS who is commenting here — Monash University in Austrailia is actually doing useful research on it. They’ve developed a diet that can help people with IBS. I disagree with some of their conclusions — they seem to think you can be on it for WAY shorter of a time than I have found is true for me, but it’s been very helpful. CBT can’t make your intestines work correctly if they don’t.

    https://www.monashfodmap.com/

    (I kept to very very low FODMAPs for at least 2 years. The initial few weeks was helpful, but I really felt better after 2 years… I’ve been on it for 8 years now, and I can eat a MUCH wider variety and amount of FODMAPs, but I still won’t put too heavy a load on my system at a time.)

  • Ian Barnes 11 February 2020, 6:54 am

    “Concerns about open-label trials with solely subjective outcomes still stands.” Quite right David! In this trial, the active treatment should have been compared to some other counselling or psychological support approach that is used in “standard care”, to enable the comparison of “apples to apples” rather than of “apples to nothing”, Objective outcome measures would not be too difficult to imagine or obtain, as you mentioned.