Comparing yoga, exercise, and a self-care book for chronic low back pain: a randomized, controlled trial.

Context Yoga combines exercise with achieving a state of mental focus through breathing. In the United States, 1 million people practice yoga for low back pain.  The authors recruited patients who had a recent primary care visit for low back pain and randomly assigned 101 to yoga or conventional exercise or a self-care book. Patients in the yoga and exercise groups reported good adherence at 26 weeks. Compared with self-care, symptoms were milder and function was better with yoga. The exercise group had intermediate outcomes. Symptoms improved between 12 and 26 weeks only with yoga.  Yoga was a more effective treatment for low back pain than a self-care book. The Editors Most treatments for chronic low back pain have modest efficacy at best (1). Exercise is one of the few proven treatments for chronic low back pain; however, its effects are often small, and no form has been shown to be clearly better than another (2-5). Yoga, which often couples physical exercise with breathing, is a popular alternative form of mindbody therapy. An estimated 14 million Americans practiced yoga in 2002 (6), including more than 1 million who used it as a treatment for back pain (7, 8). Yoga may benefit patients with back pain simply because it involves exercise or because of its effects on mental focus. We found no published studies in western biomedical literature that evaluated yoga for chronic low back pain; therefore, we designed a clinical trial to evaluate its effectiveness and safety for this condition.   This randomized, controlled trial compared the effects of yoga classes with conventional exercise classes and with a self-care book in patients with low back pain that persisted for at least 12 weeks. The study was conducted at Group Health Cooperative, a nonprofit, integrated health care system with approximately 500000 enrollees in Washington State and Idaho. The Group Health Cooperative institutional review board approved the study protocol, and all study participants gave oral informed consent before the eligibility screening and written consent before the baseline interview and randomization.  Patients from Group Health Cooperative were recruited for 12-week sessions of classes that were conducted between June and December 2003. We mailed letters describing the study to 6913 patients between 20 and 64 years of age who had visited a primary care provider for treatment of back pain 3 to 15 months before the study (according to electronic visit records). We also advertised the study in the health plan's consumer magazine. Patients were informed that we were comparing 3 approaches for the relief of back pain and that each was designed to help reduce the negative effects of low back pain on people's lives. A research assistant telephoned patients who returned statements of interest to assess their eligibility. After we received their signed informed consent forms, eligible patients were telephoned again for collection of baseline data and randomization to treatment. We excluded individuals whose back pain was complicated (for example, sciatica, previous back surgery, or diagnosed spinal stenosis), potentially attributable to specific underlying diseases or conditions (for example, pregnancy, metastatic cancer, spondylolisthesis, fractured bones, or dislocated joints), or minimal (rating of less than 3 on a bothersomeness scale of 0 to 10). We also excluded individuals who were currently receiving other back pain treatments or had participated in yoga or exercise training for back pain in the past year, those with a possible disincentive to improve (such as patients receiving workers' compensation or those involved in litigation), and those with unstable medical or severe psychiatric conditions or dementia. Patients who had contraindications (for example, symptoms consistent with severe disk disease) or schedules that precluded class participation, those who were unwilling to practice at home, or those who could not speak or understand English were also excluded. Randomization Protocol Participants were randomly assigned to participate in yoga or exercise classes or to receive the self-care book. We randomly generated treatment assignments for each class series by using a computer program with block sizes of 6 or 9. A researcher who was not involved in patient recruitment or randomization placed the assignments in opaque, sequentially numbered envelopes, which were stored in a locked filing cabinet until needed for randomization.  The yoga and exercise classes developed specifically for this study consisted of 12 weekly 75-minute classes designed to benefit people with chronic low back pain. In addition to attending classes held at Group Health facilities, participants were asked to practice daily at home. Participants received handouts that described home practices, and yoga participants received auditory compact discs to guide them through the sequence of postures with the appropriate mental focus (examples of postures are shown in the Appendix Figure). Study participants retained access to all medical care provided by their insurance plan.  Yoga postures Yoga We chose to use viniyoga, a therapeutically oriented style of yoga that emphasizes safety and is relatively easy to learn. Our class instructor and a senior teacher of viniyoga, who has +written a book about its therapeutic uses (9), designed the yoga intervention for patients with back pain who did not have previous yoga experience. Although all the sessions emphasized use of postures and breathing for managing low back symptoms, each had a specific focus: relaxation; strength-building, flexibility, and large-muscle movement; asymmetric poses; strengthening the hip muscles; lateral bending; integration; and customizing a personal practice. The postures were selected from a core of 17 relatively simple postures, some with adaptations (Appendix Table), and the sequence of the postures in each class was performed according to the rudiments of viniyoga (9). Each class included a question-and-answer period, an initial and final breathing exercise, 5 to 12 postures, and a guided deep relaxation. Most postures were not held but were repeated 3 or 6 times. Exercise Because we could not identify a clearly superior form of therapeutic exercise for low back pain from the literature, a physical therapist designed a 12-session class series that was 1) different from what most participants would have probably experienced in previous physical therapy sessions (to maximize adherence) and 2) similar to the yoga classes in number and length. We included a short educational talk that provided information on proper body mechanics, the benefits of exercise and realistic goal setting, and overcoming common barriers to developing an exercise routine (for example, fear). Each session began with the educational talk; feedback from the previous week; simple warm-ups to increase heart rate; and repetitions of a series of 7 aerobic exercises and 10 strengthening exercises that emphasized leg, hip, abdominal, and back muscles. Over the course of the 12-week series, the number of repetitions of each aerobic and strength exercise increased from 8 to 30 in increments of 2. The strengthening exercises were followed by 12 stretches for the same muscle groups; each stretch was held for 30 seconds. Classes ended with a short, unguided period of deep, slow breathing. Self-Care Book Participants were mailed a copy of The Back Pain Helpbook (10), an evidence-based book that emphasized such self-care strategies as adoption of a comprehensive fitness and strength program, appropriate lifestyle modification, and guidelines for managing flare-ups. Although we did not provide any instructions for using the book, many of the chapters concluded with specific action items. Outcome Measures Interviewers who were masked to the treatment assignments conducted telephone interviews at baseline and at 6, 12, and 26 weeks after randomization. The baseline interview collected information regarding sociodemographic characteristics, back pain history, and the participant's level of knowledge about yoga and exercise. Participants were asked to describe their current pain and to rate their expectations for each intervention. The primary outcomes were back-related dysfunction and symptoms, and the primary time point of interest was 12 weeks. We used the modified Roland Disability Scale (11) to measure patient dysfunction by totaling the number of positive responses to 23 questions about limitations of daily activities that might arise from back pain. This scale has been found to be valid, reliable, and sensitive to change (12-14); researchers estimate that the minimum clinically significant difference on the Roland scale ranges from 2 to 3 points (13, 15). Participants rated how bothersome their back pain had been during the previous week on an 11-point scale, in which 0 represented not at all bothersome and 10 represented extremely bothersome; a similar measure demonstrated substantial construct validity in earlier research (13). Estimates of the minimum clinically significant difference on the bothersomeness scale were approximately 1.5 points (16, 17). Secondary outcome measures were general health status, which we assessed by conducting the Short Form-36 Health Survey (18); degree of restricted activity as determined by patient responses to 3 questions (19); and medication use. After all outcomes data were collected, we asked questions related to specific interventions (for example, Did you practice at home?). At the 12-week interview, we asked class participants about any pain or substantial discomfort they experienced as a result of the classes. We assessed adherence to the home practice recommendations by asking class participants to complete weekly home practice logs and by asking about home practice during the follow-up i