- Top of page
- Materials and methods
- Authors’ contribution
Irritable bowel syndrome (IBS), a frequently occurring functional bowel disorder, is characterized by recurrent abdominal discomfort or pain accompanied by altered bowel habits.1 IBS has considerable economic impact,2 accounting for total annual direct costs of £45.6 million on average in the United Kingdom.3 In the Netherlands, healthcare utilization and absence from work in IBS patients are approximately twice that of the general population.4
As curative treatment is currently not available,5 therapeutic interventions are directed against predominating symptoms. These interventions include anti-spasmodics, laxatives or antidiarrhoeals in addition to patient education, reassurance and dietary advice.6 Novel therapies focus on serotonergic and psychotropic agents, but therapeutic gain is at best restricted to subgroups of patients.7–10 In addition to pharmacotherapy, efficacy of psychological interventions such as cognitive behavioural therapy, dynamic psychotherapy and hypnotherapy has been demonstrated in a number of studies.11–15 Most of these interventions, however, require multiple sessions in individual patients and are therefore time-consuming and expensive.
Relaxation training (RT) is a brief psychological intervention that can not only be provided to individuals, but also to groups of patients. Most forms of psychotherapy incorporate a relaxation technique, but sound data on the efficacy of RT as solitary treatment for IBS are lacking.16 Two studies on the efficacy of RT in IBS provided promising results but had methodological limitations (small patient number, high drop-out rate). 17, 18 We conducted a randomized controlled trial to determine short- and long-term efficacy of group RT, when added to standard medical care (CON), in a large cohort of IBS patients.
- Top of page
- Materials and methods
- Authors’ contribution
This is the first randomized controlled trial that has assessed the long-term effect of group-based RT on symptoms and quality of life in a large cohort of IBS patients. This study shows that RT leads to a significant symptom improvement, comparable to symptom reduction obtained with more comprehensive psychotherapies.11–13, 18, 24 For example, Creed et al. found that 15 months after psychodynamic interpersonal therapy, which consisted of eight individual sessions, typical IBS pain scores showed approximately 20% reduction.11 Boyce et al. found that after 1 year, bowel symptom severity was reduced by 21% in IBS patients who received RT (eight individual sessions) and by 19% in patients who received cognitive behavioural therapy (eight individual sessions).18 In both trials, symptom reduction was similar between the treatment group and the group receiving routine clinical care. Our results show that 12 months after five group sessions of RT, IBS composite scores had dropped 34% in the RT group and 12% in the CON group, i.e. a difference of 22%.
Our study extends the preliminary data and provides evidence for the efficacy of RT in treating IBS. The first explorative study on this topic suggested that symptom reduction 4 weeks after RT was greater in patients who received treatment (N = 8) compared with control patients who only monitored symptoms (N = 8).17 In this study, symptom improvement increased over time in patients who received RT and was the most pronounced after 12 months follow-up, the end point of this study. It is unlikely that this increase resulted from symptom fluctuation (a key feature of IBS), because symptom severity remained unchanged in the CON group. In our opinion, routine use of relaxation techniques in daily life, embedded in a clear rationale, provides patients with a useful tool to cope with their symptoms, and this may have a crucial role in the continuation of symptom improvement. The rationale for treatment that was provided to patients may also have contributed to patient compliance in our study: only 15 of 98 patients were lost to long-term follow-up. In a recently published trial, dropout was over 50%, which possibly explains why this study did not find greater efficacy for either RT or cognitive behavioural therapy vs. routine clinical care in IBS.18 Although some of our patients were sceptical towards the concept of RT as treatment for IBS, all were enthusiastic once the rationale had been clarified.
We acknowledge that inclusion of patients in the CON group who were initially randomized to RT but were unable to attend the scheduled training sessions, may have introduced selection bias. Additional analyses, in which these patients were included in the RT group (RT, N = 65; CON, N = 33), showed similar results for reduction in IBS composite score, overall symptom rating and gain in number of symptom-free days compared to the primary analysis, but statistical significance was not reached (data not shown). In our opinion, this is not surprising as 13 of 65 ‘RT’ patients (20%) in this analysis did not receive treatment. When these 13 patients were excluded from the analysis (RT, N = 52; CON, N = 33), which has been recommended by some authors,25 the IBS composite score was significantly reduced in the RT group compared to CON (data not shown), suggesting that RT is indeed beneficial in IBS patients who are treated with RT. Since demographic, clinical and psychological characteristics did not differ among these 13 patients and other patients (data not shown), we believe that adding these patients to the control group (which remained stable during the 1-year follow-up) did not change the outcome in this group.
Whereas some trials included only referred patients,11 we recruited Rome II-positive patients from both the hospital and from the general population, i.e. not only those who seek health care. This strategy was chosen to avoid selection bias, because patients who seek health care represent only a minority in the entire IBS population,26 and symptoms in this subgroup are usually more severe.27, 28 However, inclusion of patients with mild symptom severity may also complicate the interpretation of our results, as less improvement can be expected in this group. Although no additional analysis was performed, it is likely that patients with high symptom severity benefit most from RT simply because their symptom scores can decrease more than low baseline symptom scores. However, our primary finding that, on average, a mixed group of IBS patients having both severe and mild symptoms profits from RT further highlights the potential benefit of this therapy in an individual patient.
We aimed for a reliable distinction between responders and non-responders and therefore used the strict Jacobson and Truax criteria to measure clinically significant improvement23 in IBS composite score. It is clinically relevant to use outcome measures that represent symptom improvement, as this is the primary outcome of interest in IBS.16 Most trials have used such end points, for instance overall symptom rating15 and symptom reduction scores,11, 17 although some investigators used other outcome measures such as satisfaction with treatment.12 According to the Jacobson and Truax criteria, significantly more treated patients (23%) than controls (3%) improved 12 months after therapy. However, the RC that was utilized to define responders is in part dependent on pre-treatment score as it is calculated by the difference between pre-treatment and post-treatment scores divided by the standard error of the difference in the whole group. As a consequence, significant improvement could not be measured in 12 patients in the CON group and 15 in the RT group because of low pre-treatment scores (data not shown). The higher pre-treatment symptom severity we found in the responder group is therefore associated with the definition of responder according to the Jacobson and Truax criteria. This may underestimate true improvement.
A limitation of our study is the comparison of RT to a standard medical care control group. We cannot exclude that the efficacy of RT is the result of non-specific therapy factors, such as attention and support. A number of control interventions are available for comparison with psychological treatment, but not all of them are appropriate.25 For instance, a waiting list control group, in which patients do not receive any treatment until the trial ends, may generate negative expectations with respect to symptom improvement, and these patients may be less inclined to report improvement.25 Furthermore, the use of a placebo pill might discourage patients who are interested in trying behavioural intervention to participate, while most IBS patients have already tried several drugs to improve their symptoms, without the expected results.25
We are aware that therapist attention and support might contribute to a positive effect of RT. This may explain the difference in doctor visits between the two groups, as patients in the control group had no additional scheduled interactions, whereas patients in the RT group did. Yet, we did not control for this because RT is a minimal intervention and contains elements of patient education as part of the treatment. It is likely that an intervention controlling for attention and support also contains these elements and thereby resembles RT. Controlling for the amount of contact time (five times 90 min in this study) by employing an inert patient–therapist interaction may create an artificial situation. This may further increase the likelihood that patient education or some other form of IBS-related support takes place.
Although using standard medical care as a control intervention has methodological restrictions, such as creating a negative expectation with respect to improvement when assigned to ‘more of the same treatment’, we expected this effect to be less prominent than in the case of a waiting list control group. Nevertheless, informing these patients that they would not receive any other but their present treatment makes symptom improvement in this group less probable. This may have amplified the differences between treated patients and controls. We attempted to minimize the possible effects of non-specific therapy factors, such as attention and support, by providing highly structured training sessions to patients in the RT group. In addition, all patients in the CON group had free access to medical support from a senior gastroenterologist during the trial period, allowing patients in this group to receive the attention and support they demanded, while we were able to monitor medical consumption. In general, inspired by a previous smaller pilot study17 our main objective was to determine the efficacy of group RT as such, rather than to assess in detail which aspect of RT is responsible for its beneficial effect (i.e. relaxation, attention, support, group dynamics, etc.).
Finally, it is important to recognize that standard medical care, which was provided to all patients, is essential in treating IBS and cannot be replaced by RT alone. Dietary advice, which is considered the mainstay in IBS treatment, may improve symptoms considerably, especially in patients who report symptom deterioration after a meal. Evidence suggests that some dietary components, such as dairy products and cereals, are involved in abnormal colonic fermentation and increased colonic gas production, leading to postprandial symptom worsening.29 Furthermore, patient education on the natural course and prognosis of IBS and reassurance with respect to the benign character of IBS symptoms are also essential. These are hallmarks in present-day treatment of IBS and should not be left out.
In conclusion, our study has demonstrated short- and long-term beneficial effects of RT compared to standard medical treatment, which highlights this treatment as a promising intervention for IBS. RT reduces symptom severity, increases the number of symptom-free days and improves general health satisfaction immediately after therapy. Symptom improvement increases over time until at least 12 months after RT. Patient selection may be important as those patients with high symptom severity are likely to benefit most from RT. The efficacy of RT compared to sham intervention remains to be clarified, but the cost-effectiveness of RT compared to other psychological therapies for IBS deserves further evaluation.