By Ellen Feldman, MD

Altru Health System, Grand Forks, ND

Dr. Feldman reports no financial relationships relevant to this field of study.

EXECUTIVE SUMMARY

Researchers performed a secondary analysis of results from a trial of 69 patients comparing mindfulness meditation, cognitive therapy, or mindfulness-based therapy to treat chronic low-back pain.

A theoretical model of moderation — Limit, Activate, and Enhance (LA+E) — is employed to see if specified patient characteristics measured pretreatment are associated with greater or lesser response to each of the evidence-based psychosocial treatments utilized in the study.

While the findings do not support hypoth-esized results in full, the findings do support the likelihood that patient response to a specified intervention is based on individual characteristics; further study may help in selecting the optimal intervention for individuals.


SYNOPSIS: A theoretical model employed to predict response to either mindfulness meditation, cognitive therapy, or mindfulness-based therapy in patients with chronic low-back pain showed evidence that this type of model may be useful in determining which patients are most likely to benefit from a specified intervention.

SOURCE: Day MA ,Thorn B, Ehde DM, et al. Moderators of mindfulness meditation, cognitive therapy, and mindfulness-based cognitive therapy for chronic low back pain: A test of the limit, activate, and enhance model. J Pain 2019. pii:S1526-5900(18)30909-X. [Epub ahead of print].

Psychological treatment such as cognitive therapy or a mindfulness-based intervention have a good track record in treatment of chronic low-back pain (CLBP), especially when combined with exercise.1,2 However, data to support recommendation of one type of psychological treatment over the next is lacking.

Day et al noted that while pooled results of trials with these interventions show evidence of efficacy, individual responses to psychological interventions in CLBP vary. The goal of this study is to apply a theoretical model to understand individual variation and help predict which patient characteristics are most significant in determining response to a specified behavioral therapy. In a pilot trial involving 69 adults with CLBP, Day et al compared mindfulness meditation (MM), mindfulness-based cognitive therapy (MBCT), and cognitive therapy (CT) in treatment of CLBP. This article reports a secondary analysis of the results from the pilot trial and looks at the differential response to these interventions.

Hypothesized moderators of response were degree of pain catastrophizing (measured with a scale), data regarding alpha and theta waves (measured via electroencephalography [EEG]), and baseline strength in mindfulness (measured with two scales).

Alpha and theta waves are termed “slow-wave” oscillations and represent a nonaroused, relaxed state of mind.3 The initial hypothesis was that participants with low levels of these waves would have a strong response to mindfulness interventions.

Scales and EEG data were collected pretreatment on the 69 eligible adult patients with CLBP; the entire group was then randomized to receive one of the three therapies over an eight-week period. Follow-up outcome measures included pain interference, physical function, and depression.

The Limit, Activate, and Enhance (LA+E) model is a theoretical construct used in this study to anticipate which patients would respond better to MM, MBCT, or CT in treatment of CLBP. For example, the theory postulates that pain catastrophizing is a key limiting factor for interventions utilizing cognitive restructuring. Thus, the model predicts that patients with higher baseline catastrophizing would benefit selectively from such interventions. In fact, this was not the case, and patients who responded best to MBCT were those with low baseline levels of catastrophizing.

The LA+E model also predicted that patients with low levels of specific brain waves (alpha and theta) would selectively respond to mindfulness-based interventions. Again, this was not the case; higher levels of theta activity were associated with more robust treatment outcomes with MBCT.

Interestingly, the results indicate in many cases that there was an association between patient characteristics and differential response to a specific intervention. However, the responses were often at odds with the initial hypothesis, leading Day et al to speculate that there is a deeper complexity to predicting response than initially perceived.

In all, Day et al noted that the application of this theoretically derived model needs significant modification, but deeper analysis reveals the model has promise in understanding which patient characteristics are best suited for treatment with a specific psychological intervention. Revision of the model, replication with larger sample sizes, and control for factors, such as patient preference and cognitive deficits, are required to advance our understanding of the potential benefits of using such an approach.

Day et al bring to the table a unique, but preliminary method of determining patient suitability for a specified psychological intervention in the treatment of CLBP. The hope is that further investigation in this arena will lead to a clear indication of patient characteristics that point to a response from a specific intervention. For now, the resounding message from this study is that psychological treatment in CLBP is not “one size fits all.” This study reminds providers that patients will often have a differential response to different psychological interventions to treat CLBP, and that there is a possibility of responding to a new method if the initial intervention is unsuccessful.

REFERENCES

  1. Malfliet A, Ickmans K, Huysmans E, et al. Best evidence rehabilitation for chronic pain part 3: Low back pain. J Clin Med 2019;8:pii:E1063.
  2. Ikemoto T, Miki K, Matsubara T, et al. Psychological treatment strategy for chronic low back pain. Spine Surg Relat Res 2018;3:199-206.
  3. Herrmann N. What is the function of various brain waves? Scientific American. Dec. 22, 1997. Available at: https://www.scientificamerican.com/article/what-is-the-function-of-t-1997-12-22/. Accessed Oct. 21, 2019.