The beneficial effects are enhanced, at least in the short- and medium-term.

This study provides evidence supporting the efficacy of another treatment option for teaching patients to self-manage chronic low back pain that has a relatively low cost and that can be offered in groups.

The potential benefits of combining pain education (PE) with clinical hypnosis (CH) has not yet been investigated in individuals with chronic pain. A total of 100 patients with chronic nonspecific low back pain were randomized to receive either: 1) PE alone, or 2) PE with CH. Outcomes were collected by a blinded assessor at 2 weeks and 3 months after randomization. The primary outcomes were average pain intensity, worst pain intensity (both assessed with 11-point numeric rating scales), and disability (24-item Roland Morris Disability Questionnaire) at 2 weeks. At 2 weeks, participants who received PE with CH reported lower worst pain intensity (mean difference = 1.35 points, 95% confidence interval [CI] = .32–2.37) and disability (mean difference = 2.34 points, 95% CI = .06–4.61), but not average pain intensity (mean difference = .67 point, 95% CI = −.27 to 1.62), relative to participants who received PE alone. PE with CH participants also reported more global perceived benefits at 2 weeks (mean difference = −1.98 points, 95% CI = −3.21 to −.75). At 3 months, participants who received PE with CH reported lower worst pain intensity (mean difference = 1.32 points, 95% CI = .29–2.34) and catastrophizing (mean difference = 5.30 points, 95% CI = 1.20–9.41). No adverse effects in either treatment condition were reported. To our knowledge, this is the first trial showing that additional use of hypnosis with PE results in improved outcomes over PE alone in patients with chronic nonspecific low back pain.

Chronic nonspecific low back pain is a common conditionthat is associated with high financial costsand disability.The available biomedical interventions are typically not very effective at reducing pain or disability,are often associated with negative side effects,or involve treatment from a variety of different health care professionals, which increases costs.A relatively simple intervention provided by physical therapists—patient education—has shown efficacy, but its effects tend to be modest.One particular type of education is pain biology education, which seeks to help patients understand the biological processes related to their pain experience.This intervention has shown promise for reducing disability, catastrophizing, and increasing function.

Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990–2013: A systematic analysis for the Global Burden of Disease Study 2013.

The evolving role of physical therapists in the long-term management of chronic low back pain: Longitudinal care using assisted self-management strategies.

Hypnotic treatment for pain conditions has received more attention recently,perhaps in part because of the lack of efficacy of more traditional biomedical interventions. When used for pain treatment, hypnosis typically involves an “induction” during which the clinician invites patients to experience a state of focused awareness, followed by suggestions for changes in the sensory, cognitive, and emotional domains of pain experience.

The most recent systematic reviews conclude that hypnosis reduces pain intensity compared with usual care and when combined with other interventions for a variety of chronic conditions.Only 3 studies have investigated the effects of hypnotic suggestion in patients with chronic low back pain.Some authors have proposed that the beneficial effects of cognitive-behavioral therapy for patients with chronic pain could be enhanced by combining cognitive-behavioral therapy with hypnosis.Combining pain education (PE) with hypnosis has not yet been investigated, however.

Effects of self-hypnosis training and cognitive restructuring on daily pain intensity and catastrophizing in individuals with multiple sclerosis and chronic pain.

With these considerations, we designed the current study to evaluate the effects of additional use of hypnosis with PE. We hypothesized that patients with chronic low back pain who received PE with hypnosis would report greater improvements in pain intensity and disability (primary outcomes) as well as patient-specific function, catastrophizing, and global perceived benefits (secondary outcomes), relative to those randomized to receive PE alone.

Statistical analyses were conducted using intention to treat principles. The between-group differences and their respective 95% confidence intervals (CIs) were calculated using linear mixed models. We also estimated the number needed to treat for the primary outcomes by dichotomizing patients who had reached the minimal clinically important difference compared with those who had not reached minimal clinically important difference. The cutoffs used for determining minimal clinically important differences in pain intensity (a reduction of at least 2 points or 30% on the NRS scale, relative to baseline) and disability (a reduction of at least 5 points or 30% on the RMDQ, relative to baseline) was determined on the basis of previous studies relating these scales to global assessments of change.We used SPSS version 22 for Mac (IBM Corp, Armonk, NY) for all statistical analyses.

We designed the study to detect a between-group difference of at least 1 point in pain intensity measured using the NRS, with an estimated SD of 2 points, and a between-group difference of 4 points for disability measured using the RMDQ, with an estimated SD of 5 points.The specifications were: a power of 80%, an α coefficient of .05, and a possible loss to follow-up of up to 15%.Therefore, a total of 100 participants were enrolled in the study. The estimates for powering the study were lower than the minimal clinical important difference for patients with low back pain.The rationale for powering the study to detect a change in pain that is less than the minimally clinically important difference was that most published clinical trials of PE have not achieved this effect size. Therefore, we designed the study to be sufficiently powered to be able to detect at least the effect sizes shown in earlier studies.

The primary outcome measures were pain intensity (average and the worst pain over the past week, measured using a 0–10 pain NRS)and disability (measured using the 0–24 Roland Morris Disability Questionnaire [RMDQ])at 2 weeks after randomization. The secondary outcome measures were: 1) pain intensity (average and worst pain)and disabilityassessed at 3 months after randomization, 2) catastrophizing (measured using the 0–52 Pain Catastrophizing Scale,3) function (measured using the 0–10 Patient-Specific Function Scale),and 4) global impression of change (measured using the −5 to +5 Global Perceived Effect Scale)at 2 weeks and 3 months after randomization. Sociodemographic and clinical information and expectation of improvement with the treatment were obtained at baseline. During all telephone follow-up interviews, the occurrence of potential adverse effects was assessed by asking: “Since you started receiving this treatment, have your symptoms become worse?” To assess the expectation of improvement with the treatment, the follow question was asked: “In your opinion, what is your expectation that your symptoms will improve with this treatment (measured using the 0–10 expectation numeric rating scale)?”All outcome measures used in this trial were cross-culturally adapted into Brazilian Portuguese and successfully tested for their measurement properties.There were no changes made to the outcome measures after trial commencement.

Psychometric characteristics of the Brazilian-Portuguese versions of the Functional Rating Index and the Roland Morris Disability Questionnaire.

Clinimetric testing of three self-report outcome measures for low back pain patients in Brazil: Which one is the best?.

Global Perceived Effect scales provided reliable assessments of health transition in people with musculoskeletal disorders, but ratings are strongly influenced by current status.

Clinimetric testing of three self-report outcome measures for low back pain patients in Brazil: Which one is the best?.

Psychometric characteristics of the Brazilian-Portuguese versions of the Functional Rating Index and the Roland Morris Disability Questionnaire.

Clinimetric testing of three self-report outcome measures for low back pain patients in Brazil: Which one is the best?.

Psychometric characteristics of the Brazilian-Portuguese versions of the Functional Rating Index and the Roland Morris Disability Questionnaire.

Clinimetric testing of three self-report outcome measures for low back pain patients in Brazil: Which one is the best?.

Patients were evaluated by an assessor who was blind to treatment allocation at baseline and after 2 weeks and 3 months after randomization. Patients who did not finish all interventions in 2 weeks had an opportunity to complete the sessions in the following 2 weeks. After this period, the first follow-up assessment (2-week follow-up) was concluded. All baseline assessments were conducted in person. Participants who completed all 4 sessions were evaluated in person, and participants who did not complete all 4 sessions were evaluated via telephone at 2 weeks. All patients were contacted at 3 months via telephone to collect follow-up data.

During the fourth class, the participants were given 3 different hypnotic suggestions. The first 2 were related to the motor responses. The first was a “deep relaxation” suggestion,during which participants were invited to relax each muscle of their body. The second was an “age regression and progression” suggestion,during which participants were invited to bring adaptive pain responses from the past or the future into the present. Both of these hypnotic suggestions reinforced the importance of physical movement as a way to extend the benefits. The last hypnotic experience of this class offered a metaphor to help the patients use some of the information they had learned to manage negative thoughts during the day. After each class, the participants were asked to read the hypnosis workbook and to practice self-hypnosis briefly at home. The Explain Pain workbook was also provided during the last session.

Patients were given 2 hypnotic suggestions during the third class. The first was connected to the idea that “the brain can receive amplified messages from the tissues, even when there is nothing wrong with the structure of the body,”and included suggestions for decreased pain unpleasantness, which invited participants to experience comfort even with the presence of some sensations in their body.The second hypnotic suggestion was related to the idea of “the brain orchestra can play a different song.”We offered “sensory substitution” suggestions,which invited participants to experience a comfortable sensation of their hands spreading to other parts of the body.

Patients had 2 hypnotic experiences during the second class. The first experience was connected to the idea expressed in the Explain Pain book that “… sensors are often replaced by new and fresh ones.”We offered through hypnotic suggestions that an adaptation in the sensors is possible.The second hypnotic experience was related to the content of descending inhibitory modulation at the level of the spinal cord. The suggestion was adapted hypnotic analgesia,which invites patients to experience analgesic sensations in their body.

The first hypnotic experience was intended to suggest an openness to the possibility of change. The suggestions reinforced the idea that the brain has many capacities that can be used to create comfortable experiences. Some brief suggestions explored the capacities of relaxation, dissociation (between body and mind), analgesia, and age regression to previous pleasant experiences.

To increase acceptability of hypnosis to the participants, the PE content was interspersed with hypnotic suggestions. For example, the participants were told, “Each hypnotic experience is intended to adjust each part of the danger alarm system.” The hypnotic inductions started with stories and metaphors related to the PE content. After this, the participants were invited to focus their attention while looking at a spot on the wall in front of them. Brief summaries of the content of each hypnotic session are described in the following 4 sections (more detailed information about the content of the hypnotic suggestions are provided in Appendix 1 ).

Participants allocated to the PE with CH (PE + CH) group received a total of 6 hours and 15 minutes of treatment. The only difference between the PE and the PE + CH groups was the additional use of a total of 2 hours and 15 minutes of hypnosis distributed over the 2 weeks of treatment, and a hypnosis workbook to read at home with the same hypnotic suggestions offered in the classes. To ensure that the content of the PE treatment component was the same for both groups, the hypnotic suggestions were added to the PE components. For this reason, the total duration of sessions was different between groups.

The PE group classes used the same pictures, stories, metaphors, and examples described in the Explain Pain book.Participants were encouraged to ask questions during the classes. At the end of each class, the information presented was reviewed. A workbook was given to the participants with the same content offered during the classes, and the participants were asked to read the content after each class at home. Information provided during the classes included: pain as a normal experience (first class); components and function of the danger alarm system, and modulation of danger messages at the spinal cord level (second class); altered central nervous system alarms, and response systems in the pain experience (third class); and education and understanding that “hurt does not necessarily equal harm,” pacing and graded exposure (fourth class).

Participants from both groups received PE on the basis of information from the Explain Pain book,and the second group received additional hypnotic suggestions. Both interventions were provided in the same group setting. The interventions were carried out in a group with up to 7 participants per class (varying from 1 to 7 participants). The frequency (4 sessions, twice a week) and content of PE were standardized in both groups. Participants from both groups received a workbook with the same PE content given in each class. The clinician who treated the patients from both groups (R.R.N.R.) is a physical therapist with 13 years of clinical experience, including 6 years of experience in the delivery of PE and clinical hypnosis (CH) for pain. The therapist was certified in hypnotherapy and received guidance from a psychologist certified by the American Society of Clinical Hypnosis.

The outcome assessor was blind to group allocation. Because of the nature of interventions, it was not possible for the therapist or the study participants to be blind to treatment condition.

A simple randomization sequence was generated using the Microsoft Excel (Redmond, WA) program by one of the study investigators who was not directly involved with the study assessments or treatment. During the baseline assessment, participants received information about the study and signed a consent form to participate in the study. After the baseline assessment the therapist opened the randomization envelope and the participant was allocated to 1 of the 2 treatment groups. The allocation was concealed by using consecutively numbered, sealed, opaque envelopes. The envelopes were opened when the participants arrived for treatment, and the first session was conducted immediately after the baseline assessment that same day.

Potential participants were informed that they would be randomized to receive 1 of “two different widely used pain education programs that have been found to be helpful for patients with chronic pain.” Patients were invited to participate if they had nonspecific low back pain of at least 3 months, were aged between 18 and 80 years old, and had a minimum score of 3 on 0 to 10 pain numeric rating scale (NRS) of average pain intensity. Patients who were receiving physical therapy at the time of recruitment, with any contraindication to exercise, serious spinal pathologies, previous spinal surgery, nerve root compromise, cardiorespiratory illness, pregnancy, hearing problems, low back pain as secondary complaint, illiteracy, or inability to attend treatment sessions were excluded. The institutional human ethics committee of the Universidade Cidade de São Paulo approved this trial. All study participants provided written informed consent.

This trial was prospectively registered at clinicaltrials.gov : NCT02638753. There was no deviation from the original registered protocol. This was a 2-arm randomized controlled trial with the outcome assessor blinded to the group allocation ( Fig 1 ). The primary source of participants was the waiting list of the outpatient physical therapy clinic of the Universidade Cidade de São Paulo, Brazil. The interventions were conducted in classrooms of the university from February to November 2016.

Participant flow diagram. All patients received the treatments as allocated. Overall follow-up response rates were 99% (n = 99) at 2-week and 3-month follow-ups.

Figure 1 Participant flow diagram. All patients received the treatments as allocated. Overall follow-up response rates were 99% (n = 99) at 2-week and 3-month follow-ups.

The percentage of patients who reported increased pain at 3-month follow-up was 12% (n = 6) in the PE group, and 8% (n = 4) in the PE + CH group (a nonsignificant difference; χ 2 = .40, P = .53). No serious adverse effects were reported.

Participants in both groups reported similar frequency of home practice at 3 months (never or little: 14% in the PE and 20% in the PE + CH group; somewhat: 50% in the PE and 40% in the PE + CH group; much: 36% in the PE and 38% in the PE + CH group).

The expectation of improvement between the groups were very similar at 2-week (MD = −.00 point, 95% CI = −.70 to .68) and at 3-month follow-ups (MD = −.23 point, 95% CI = −.92 to .46).

With respect to the secondary outcomes, there was significant difference in favor of the PE + CH group for catastrophizing at 3 months (MD = 6.78 points, 95% CI = 2.08–11.48) and global perceived benefits at 2 weeks (MD = 1.98 points, 95% CI = −3.25 to −.71; Table 2 ). The numbers needed to treat were 2.9 (95% CI = .3–.7) for the worst pain intensity and 5.1 (95% CI = .4–1.0) for disability at 2 weeks in favor of the PE + CH group.

There was no significant differences between the groups in average pain intensity at 2 weeks (mean difference [MD] = .67 point, 95% CI = −.27 to 1.62) or 3 months (MD = .09 point, 95% CI = −.85 to 1.04). However, patients enrolled in the PE + CH group reported lower worst pain intensity at 2 weeks (MD = 1.35 points, 95% CI = .32–2.37) as well as 3 months (MD = 1.32 points, 95% CI = .29–2.34). They also reported significantly greater reductions in disability at 2 weeks (MD = 2.34 points, 95% CI = .06–4.61; Table 2 ).

NOTE. Unadjusted Mean Outcomes presented as Mean Difference (MDs) and Standard Deviation (SD). Adjusted Treatment Effect presented as MDs and Confidence Interval of 95% (95% CI). Positive scores for treatment effect favor pain neurophysiology education with hypnosis for outcomes of pain intensity, disability, catastrophizing, and function. Negative scores favor the pain neurophysiology education with hypnosis for the outcome of global perceived effect. Primary outcomes are highlighted in gray.

The baseline sociodemographic and clinical characteristics were similar in both groups ( Table 1 ). Most participants in both groups were women, with secondary level education, with a median duration of pain of 4 years and with moderate levels of average pain intensity and disability. Participants in both groups started treatment with a high expectation of improvement.

NOTE. Categorical variables are expressed as n (%), continuous variables are expressed as mean (SD), and duration of pain is expressed as median (interquartile range).

All patients received the treatments as allocated. In the PE group, 86% (n = 43) of the patients attended all classes, 8% (n = 4) attended 3 classes, 4% (n = 2) 2 classes and 2% (n = 1) only 1 class of the program. In the PE + CH group, 88% (n = 44) attended all 4 classes, 2% (n = 1) 3 classes, 2% (n = 1) 2 classes, and 8% (n = 4) attended only 1 class of the program. Overall follow-up response rates were 99% (n = 99) at 2 weeks as well as 3 months. One of the patients in the PE + CH group dropped out of the study and was lost to follow-up.

Two hundred seventy patients who were seeking care for low back pain at the physical therapy clinic from February to November, 2016, were approached for possible participation. Forty-three (16%) of these declined participation, 127 (47%) were excluded and 100 (37%) were eligible and agreed to participate ( Fig 1 ). The primary reasons for exclusion were inability to attend treatment sessions (n = 33), low back pain as secondary complaint (n = 25), presence of an acute low back pain episode (n = 17), being younger than 18 years old or older than 80 years old (n = 13), receiving physical therapy at the time of recruitment (n = 12), having hearing problems (n = 8), being illiterate (n = 6), having a history of previous spinal surgery (n = 4), presence of signs of nerve root compression (n = 3), having no interest in hypnosis (n = 2), having no interest in PE (n = 2), the presence of cardiorespiratory illness (n = 1), and pregnancy (n = 1).

Discussion

To our knowledge, this is the first randomized controlled trial that has investigated the beneficial effects of combining CH with PE for patients with chronic pain. We found that the additional use of CH with PE resulted in improved outcomes of worst pain intensity, disability, and global perceived benefits in the short-term, compared with PE alone. Moreover, additional use of PE with CH maintained its superiority over PE alone for reducing the worst pain intensity at medium-term, and also showed additional benefits in reducing catastrophizing at medium-term.

21 Jensen M.P.

Gertz K.J.

Stoelb B.

Dillworyh T.M.

Hirsh A.T.

Molton I.R.

Kraft G.H. Effects of self-hypnosis training and cognitive restructuring on daily pain intensity and catastrophizing in individuals with multiple sclerosis and chronic pain. 21 Jensen M.P.

Gertz K.J.

Stoelb B.

Dillworyh T.M.

Hirsh A.T.

Molton I.R.

Kraft G.H. Effects of self-hypnosis training and cognitive restructuring on daily pain intensity and catastrophizing in individuals with multiple sclerosis and chronic pain. 10 Daut R.L.

Cleeland C.S.

Flanery R.C. Development of the Wisconsin Brief Pain Questionnaire to assess pain in cancer and other diseases. 25 Jensen M.P.

Tome-Pires C.

de la Vega R.

Galan S.

Sole E.

Miro J. What determines whether a pain is rated as mild, moderate, or severe? The importance of pain beliefs and pain interference. 29 Kjogx H.

Kasch H.

Zachariae R.

Svensson P.

Jensen T.S.

Vase L. Experimental manipulations of pain catastrophizing influence pain levels in patients with chronic pain and healthy volunteers. , 38 Meyer K.

Tschopp A.

Sprott H.

Mannion A.F. Association between catastrophizing and self-rated pain and disability in patients with chronic low back pain. We prospectively registered the worst pain intensity as a primary outcome because similar hypnotic suggestions have been shown to influence this outcome in other chronic pain conditions.Jensen and colleagues compared CH with cognitive restructuring and did not find a statistically significant difference in the average pain intensity, but detected a statistical difference in the worst pain intensity.The reasons for finding significant effects for worst pain intensity but not for average pain intensity are not entirely clear. It is possible that when rating average pain intensity, patients might consider different cognitive and emotional references than when rating worst pain intensity. Also, worst pain intensity tends to be more strongly correlated with pain interference (mood, social relationships, walking, work and enjoyment of life) than average pain.Recently, a study showed that a scale for measuring pain intensity may reflect patients' perceptions about pain interference and beliefs about their pain, and not only pain intensity.In our study, patients who received CH also evidenced a larger reduction in catastrophizing. There is evidence that catastrophizing may, at least in part, influence pain intensity in chronic pain conditions.Overall, the findings suggest the possibility that a greater variety of pain experience domains might be influenced by CH than PE alone. Future studies could shed some light on this by testing the causal mechanisms that underlie the effect of CH on different pain-related outcomes, including worst pain intensity.

36 McCauley J.D.

Thelen M.H.

Frank R.G.

Willard R.R.

Callen K.E. Hypnosis compared to relaxation in the outpatient management of chronic low back pain. , 48 Spinhoven P.

Linssen A.C. Education and self-hypnosis in the management of low back pain: A component analysis. , 50 Tan G.

Rintala D.H.

Jensen M.P.

Fukui T.

Smith D.

Williams W. A randomized controlled trial of hypnosis compared with biofeedback for adults with chronic low back pain. 21 Jensen M.P.

Gertz K.J.

Stoelb B.

Dillworyh T.M.

Hirsh A.T.

Molton I.R.

Kraft G.H. Effects of self-hypnosis training and cognitive restructuring on daily pain intensity and catastrophizing in individuals with multiple sclerosis and chronic pain. , 28 Kirsch I.

Montgomery G.

Sapirstein G. Hypnosis as an adjunct to cognitive-behavioral psychotherapy: A meta-analysis. , 40 Moseley L.G. Combined physiotherapy and education is efficacious for chronic low back pain. , 46 Ryan C.G.

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Granat M.H. Pain biology education and exercise classes compared to pain biology education alone for individuals with chronic low back pain: A pilot randomised controlled trial. 46 Ryan C.G.

Gray H.G.

Newton M.

Granat M.H. Pain biology education and exercise classes compared to pain biology education alone for individuals with chronic low back pain: A pilot randomised controlled trial. 21 Jensen M.P.

Gertz K.J.

Stoelb B.

Dillworyh T.M.

Hirsh A.T.

Molton I.R.

Kraft G.H. Effects of self-hypnosis training and cognitive restructuring on daily pain intensity and catastrophizing in individuals with multiple sclerosis and chronic pain. Previous studies that have evaluated the efficacy of hypnosis treatment (alone) for chronic low back pain showed no additional benefits for pain intensity, relative to other active psychosocial pain treatments such as PE, biofeedback, and relaxation.The current findings suggest the possibility that combining different psychosocial interventions may boost their overall efficacy. However, it is important to keep in mind that the component parts of combination treatments may influence efficacy.For example, exercise therapy has been shown to reduce the beneficial effects of pain neuroscience education in patients with chronic low back pain.However, there is also evidence that hypnosis can increase the beneficial effects of cognitive-behavioral therapy for reducing worst pain intensity in patients with chronic pain and multiple sclerosis.Research is needed to help determine which treatment combinations are most effective for most patients.

This study has some important limitations that should be considered when interpreting the results. As is the case with all psychosocial interventions, neither the therapist nor the patients were blind to treatment condition. Thus, although the pain educational content and PE treatment time were the same in both treatment conditions, the participants in the PE with hypnosis condition received more therapist attention overall, because of the additional time needed for hypnosis. Further studies could compare the effects of PE with hypnosis versus PE with another intervention to control the potential effects of therapy time. In addition, a single therapist who was aware of the study hypotheses conducted the interventions; further research is therefore needed to determine if the current findings generalize to other therapists, including those who might not be aware of the study hypotheses.