Yoga for chronic low back pain in a predominantly minority population: a pilot randomized controlled trial

Abstract

Background: Several studies suggest yoga may be effective for chronic low back pain; however, trials targeting minorities have not been conducted. PRIMARY STUDY OBJECTIVES: Assess the feasibility of studying yoga in a predominantly minority population with chronic low back pain. Collect preliminary data to plan a larger powered study.

Study design: Pilot randomized controlled trial.

Setting: Two community health centers in a racially diverse neighborhood of Boston, Massachusetts.

Participants: Thirty English-speaking adults (mean age 44 years, 83% female, 83% racial/ethnic minorities; 48% with incomes < or = $30,000) with moderate-to-severe chronic low back pain.

Interventions: Standardized series of weekly hatha yoga classes for 12 weeks compared to a waitlist usual care control.

Outcome measures: Feasibility measured by time to complete enrollment, proportion of racial/ethnic minorities enrolled, retention rates, and adverse events. Primary efficacy outcomes were changes from baseline to 12 weeks in pain score (0=no pain to 10=worst possible pain) and back-related function using the modified Roland-Morris Disability Questionnaire (0-23 point scale, higher scores reflect poorer function). Secondary efficacy outcomes were analgesic use, global improvement, and quality of life (SF-36).

Results: Recruitment took 2 months. Retention rates were 97% at 12 weeks and 77% at 26 weeks. Mean pain scores for yoga decreased from baseline to 12 weeks (6.7 to 4.4) compared to usual care, which decreased from 7.5 to 7.1 (P=.02). Mean Roland scores for yoga decreased from 14.5 to 8.2 compared to usual care, which decreased from 16.1 to 12.5 (P=.28). At 12 weeks, yoga compared to usual care participants reported less analgesic use (13% vs 73%, P=.003), less opiate use (0% vs 33%, P=.04), and greater overall improvement (73% vs 27%, P=.03). There were no differences in SF-36 scores and no serious adverse events.

Conclusion: A yoga study intervention in a predominantly minority population with chronic low back pain was moderately feasible and may be more effective than usual care for reducing pain and pain medication use.

Figures

FIGURE 1

Participant Flow Diagram

FIGURE 2

The x-axis is time from initiation of yoga classes. The y-axis is the mean low back pain intensity in the previous week on an 11-point numerical rating scale. The yoga group received hatha yoga classes weekly for 12 weeks. Both groups received an educational book on self-care management of low back pain and continued their usual medical care. P values for any difference in mean pain scores between groups (calculated by comparing mean pain change scores from baseline using the Wilcoxon rank sum test) are .25 and .02 at 6 and 12 weeks, respectively.

FIGURE 3

The x-axis is time from initiation of yoga classes. The y-axis is the modified 23-point Roland Disability Scale mean score. Higher scores reflect worse back pain–related function. The yoga group received hatha yoga classes weekly for the first 12 weeks of the study. Both groups received an educational book on self-care management of low back pain and continued their usual medical care. P values for any difference in mean Roland Disability scores between groups (calculated by comparing mean Roland change scores from baseline using the Wilcoxon rank sum test) are .29 and .28 at 6 and 12 weeks, respectively.

FIGURE 4

The top and bottom panels show pain medication use by the yoga and usual care groups, respectively. For each medication category, use at baseline, 6, and 12 weeks is displayed. Bar heights reflect the percentage of participants reporting any use within the previous week. Pain medication use was compared between groups at 6 and 12 weeks using exact logistic regression with 6-week or 12-week medication use as the dependent variable and baseline medication use and group assignment as the independent variables. Examples of “other” types of pain medicine included tramadol, gabapentin, and amitryptiline.

APPENDIX FIGURE

The yoga postures (asanas) shown were part of a standardized hatha yoga protocol developed for chronic low back pain in individuals with little or no yoga experience. To design the protocol, we performed a systematic search of the peer-reviewed and lay literature on yoga for low back pain. We collected and distributed this literature to an expert panel with a broad range of experience in different yoga styles. After reviewing the literature, the panel met and synthesized information from the literature with their professional experience to draft a protocol that was subsequently refined iteratively through discussion, consensus, and use in nonstudy yoga classes.

APPENDIX FIGURE

The yoga postures (asanas) shown were part of a standardized hatha yoga protocol developed for chronic low back pain in individuals with little or no yoga experience. To design the protocol, we performed a systematic search of the peer-reviewed and lay literature on yoga for low back pain. We collected and distributed this literature to an expert panel with a broad range of experience in different yoga styles. After reviewing the literature, the panel met and synthesized information from the literature with their professional experience to draft a protocol that was subsequently refined iteratively through discussion, consensus, and use in nonstudy yoga classes.