4 Points Arising from Low-Back Pain Study

For MTs and Their Practices

By Niki Munk, PhD
[Somatic Research]

I am so pleased to be writing my first Somatic Research column for Massage & Bodywork! Last issue (November/December 2017, “Real-World Massage Research,” page 44), Jerrilyn Cambron’s departing article highlighted several aspects of the University of Kentucky’s real-world massage therapy study examining chronic low-back pain (CLBP) recently published in Pain Medicine.1
The research was an NIH-funded study to examine the effectiveness of massage therapist-directed treatment for primary-care patients with CLBP. Study participants were referred by their primary-care provider to the study and matched with a community massage therapist who practiced near where they lived or worked. Study therapists were allowed to provide 10 one-hour massage treatments over 12 weeks as part of the study and managed all aspects of appointment scheduling, timing, and delivery.2 The study used a repeated-measures design and collected data prior to any intervention (baseline); 12 weeks after baseline, during which participants received up to 10 one-hour massage therapy treatments (12 weeks); and 12 weeks after the massage intervention window to provide a follow-up of lasting effects (24 weeks). The study’s general outcomes indicated that a course of real-world massage therapy reduced low-back pain with disability and improved functional related quality of life for real-world, complex CLBP patients referred from primary-care providers. While treatment benefits did generally recede for participants from data collected at 12 weeks and 24 weeks, baseline to 24 weeks comparisons were still significant for most of the study’s primary outcomes, indicating overall improvement and lasting effects for many in the study.  
This column will answer four specific questions arising from the Pain Medicine article and highlight the study results’ finer points that are of applicable interest to massage therapists and their practices: (1) If massage benefits after a course of massage reduce three months later, does that mean massage wasn’t beneficial?
(2) What is the Oswestry Disability Index (the study’s main outcome measure) and can it be used in massage therapy practice? (3) What is the difference between statistically and clinically meaningful outcomes? (4) What participant characteristics may have influenced massage effectiveness and lasting benefit?

1. Curative Versus Management Considerations
A majority of study participants experienced meaningful decreases in their pain with disability after the massage intervention. Seventy-five percent of those reporting meaningful improvement at 12 weeks still had meaningful improvement at 24 weeks. The question becomes: If not everyone experienced benefit in the first place, and some who had benefit lost it after massage was discontinued, can it be said that massage therapy is effective for CLBP? The short answer derived from this study’s data is yes; for many, massage therapy was beneficial for CLBP and related disabilities. A point at the heart of this question, however, is the difference between a curative and management massage approach. The way this and most other research studies are designed examines an intervention’s ability to cure a condition. A set amount of treatment is given to address a condition—in this case CLBP, after the treatment is concluded, the intervention’s lasting effects are assessed. What this design approach does not account for is the fact that many people’s chronic pain (including some with CLBP) comes from conditions that are progressive in nature (e.g., osteoarthritis, scoliosis, degenerative disc disease, etc.) and are not actually curable, at least not from massage therapy. Other people may be in situations where their chronic pain is perpetuated by physical demands placed on them by their jobs or other meaningful life experiences that also can’t or won’t change. These situations are also not curable by massage therapy, but massage can help manage the extent to which pain is experienced from these necessary and continued activities. More often than not, these management-type situations are those that massage therapists work with in their daily clinical experiences and are the next needed step in massage therapy research. This study determined that for most real-world primary-care patients with CLBP, a course of 10 one-hour real-world massage treatments over 12 weeks provided meaningful improvement in pain with disability.  
The next question research should tackle is how often does real-world massage need to be provided in order for people with CLBP to maintain and/or continue improving after an initial course of massage therapy is complete? Studies designed to answer questions like this could help to turn research toward the more massage practice-reflective approach to chronic pain conditions: management. Keep your eyes peeled to future research. Hopefully we will see these types of developments in the coming years.

2. Oswestry Disability Index (ODI)
This study used the ODI to measure pain-related disability for people with CLBP. The ODI is a valid and reliable measure specific to back pain that is easy to use in research and practice settings.3 The ODI consists of 10 sections, each focused on a specific aspect of meaningful function: personal care, lifting, walking, sitting, standing, sleeping, sex, social, traveling, and general pain intensity. Each section contains six statements related to its topic in order of severity progression. People taking the ODI are asked to select which one statement under each section best applies to them. Initial statements for each section are scored at zero and indicate no issue or pain related to the section topic. After four additional progressive statements scored 1–4, final statements for each section are scored 5 and indicate extreme limit and/or disability and pain. By way of example, below are the progressing statements for the “sitting” section of the ODI:4

I can sit in any chair as long as I like.
I can only sit in my favorite chair as long as I like.
Pain prevents me from sitting more than 1 hour.
Pain prevents me from sitting more than 30 minutes.
Pain prevents me from sitting more than 10 minutes.
Pain prevents me from sitting at all.

Simple scoring instructions applied to a completed ODI produce a disability percentage, with those scoring 12 percent or higher considered experiencing back-related pain with disability.5 A change of 6 percentage points or more is considered clinically meaningful and the ODI’s use is not proprietary (in other words, use and access of the ODI is free).6 While primary analysis for the study considered group ODI mean scores and their changes at the study’s three data-collection time points, a descriptive consideration of individual ODI scores and changes from baseline to 12 weeks provides a more practice-relevant picture of this study’s participant outcomes. The below tables display ODI section responses at baseline (left column) and 12 weeks (right column) for two study participants.
These two participant examples provide two different ways in which people in the study experienced improved back-related pain with disability. The first table depicts a participant who began the study with moderate disability (40 percent) and after a 30 percent point reduction in ODI from baseline to 12 weeks, concluded the intervention window of the study below the ODI threshold for pain with disability (12 percent). This particular participant had a 75 percent improvement in ODI score from baseline to post-intervention and several meaningful life functions such as personal care, sitting, standing, sleep, and sex dramatically improved. The second participant example began the study with more severe disability and experienced a less pronounced but still clinically meaningful change of 14 percentage points. Although this participant was still moderately disabled at the massage intervention’s conclusion, the 26 percent improvement in ODI score included benefit in several meaningful life functions such as lifting, sex, and travel. While changes were not as robust for the second example participant, anyone who has experienced chronic pain conditions knows the big impact changes like this make in life from a pain-management perspective.   

3. Statistical Versus Clinically Meaningful
The real-world massage therapy for CLBP study highlighted both statistically and clinically meaningful results, which is sometimes a point of confusion. You may even be asking yourself: What’s the difference? To answer this question, I will try not to get too deep into the statistical weeds. Essentially, if there is a large enough sample, small differences between groups can become statistically significant. On the flip side, in small samples, differences between groups have to be really, really large in order for statistical significance to be achieved. This can be problematic for two related, but distinct, reasons. First, if a little change is statistically significant in a large (or small for that matter) sample but doesn’t matter in a person’s life or in a practical setting (say a 0.05 millimeter decrease in pain score on a 100 millimeter line), who cares if that outcome is statistically significant or not? It makes no real difference in an applied example or for an actual person. Second, exclusive focus on p-values and statistical significance can really miss important, patient-centered outcomes. If a researched intervention consistently demonstrates meaningful change in people’s lives or for particular conditions, should the value or worth of said intervention be totally based on whether a study’s p-value achieves <0.05? This issue becomes particularly challenging for situations in which research with large samples is limited due to funding, availability of eligible participants, or other research barriers. In your research reading, look for the extent to which study results are framed in terms of established, clinically meaningful outcomes. Or, if clinically meaningful minimums are not available or reported, consider what a study’s research outcomes would mean in a person’s life if applied at an individual level. This will help contextualize research numbers, especially for those intimidated by statistics.  
This study addressed the statistical versus clinical significance question in a couple of ways. Researchers conducted a power analysis prior to beginning the study to determine the needed sample size to detect the minimum clinically meaningful change for the primary outcome measure (as noted in the Oswestry Disability Index discussion, a change of 6 percentage points or more is considered clinically meaningful for the ODI). In addition, study analysis results were repeatedly put in the context of the extent to which clinically meaningful change was achieved. These attentions to clinically meaningful change by this research team reflect a patient-centered consideration of study results and provide massage therapists with a practice-relevant metric by which their clients’ massage outcomes for pain and disability related to back pain can be compared.     

4. Characteristics that Might Influence Massage Effectiveness
The study’s exploratory analysis uncovered some interesting participant-related factors that may have influenced massage effectiveness. Specifically, analysis determined that after the intervention window, those who were 50 years and older had significantly better outcomes than those who were younger based on mean ODI change scores (4.6 ± 9.7 for younger participants versus 10.3 ± 10.8 for older participants; p=0.01). The astute reader will note that the average ODI change score for younger participants was not clinically meaningful (less than a 6 percentage point change) while those who were older had an average ODI change score well above what is considered clinically meaningful. These findings may suggest a couple of interesting items for massage therapists within their practices.  
First, those who are older have potentially been managing chronic-pain conditions for longer, perhaps making them better able to appreciate massage therapy’s benefit. These clients may also be more inclined or able (not something investigated in this study) to make adjustments to their daily lives and behaviors that may perpetuate or add to their CLBP experience. While self-care advice was not something examined in this study, it is well-known (and practiced) in the massage and bodywork field that practitioners will give clients “homework” or other self-care advice. It is also well documented in the medical literature that older patients are more compliant to prescribed medical care than younger patients when cognitive issues are absent.7 Such compliance-related age differences may have been a factor in this study’s older participants responding better to massage if study therapists provided self-help recommendations in addition to the massage treatment. Second, the differences in age-outcome findings could also have been from older people having a more realistic expectation of, and appreciation for, chronic-condition management. Those who have experienced chronic-pain conditions longer are inherently older and, given the longer pain experience duration, may interpret benefits in more pronounced ways than those who have not endured pain for as long.  
Exploratory analysis also found interesting differences in outcomes based on obesity status. Although those who were obese had more pronounced benefits postmassage intervention than those who were not obese, the changes overall from baseline to follow-up (24 weeks) was smaller for obese individuals compared to non-obese participants, indicating that pronounced benefit postintervention was not retained once massage therapy stopped. These findings could suggest that those who are obese should consider massage therapy as a management approach for their CLBP unless interventions to address weight (which can also contribute to CLBP)8 are included in their CLBP treatment strategy.  

Continuing the Discussion
The real-world massage therapy for CLBP study recently published in Pain Medicine provides several aspects that are clinically relevant to massage and bodywork practice. In addition to reporting research results conducted in practice settings reflective of the massage field, it also introduces massage and bodywork practitioners to an easy tool to measure pain with disability for those with acute or chronic back pain and provides a discussion example for clinical versus statistical significance and curative versus management intervention approaches.  
I look forward to continuing these and other pertinent themes’ discussion and application to massage practice and education in future Somatic Research columns as we critically consider current massage research together.

1. Real world essentially means what it implies: as it happens or occurs in the real world, in real applications. The words pragmatic and effectiveness are related research terms that indicate, along with real world, that the research does not seek to examine interventions or make observations in controlled settings. Our study design was real world from several perspectives. We had a very open inclusion criteria, which allowed for medically complex participants who are often excluded from research or controlled studies. For example, we did not have an upper age limit for participants, which allowed us to include much older participants who, up to that point, had been excluded from large clinical trials examining massage for back pain. We also allowed chronic low-back pain patients with comorbidities such as diabetes, hypertension, depression, and obesity to participate, as well as patients who were on scheduled medications such as opioids. Essentially, the participants in this study reflect the real world: complex individuals who massage therapists work with every day in a variety of practice settings, all across the country; W. G. Elder and N. Munk et al., “Real-World Massage Therapy Produces Meaningful Effectiveness Signal for Primary Care Patients with Chronic Low Back Pain: Results of a Repeated Measures Cohort Study,” Pain Medicine 18 (2017): 1,394–405.  
2. N. Munk et al., “Intersection of Massage Practice and Research: Community Massage Therapists as Research Personnel on an NIH-Funded Effectiveness Study,” International Journal of Therapeutic Massage & Bodywork 7, no. 2 (2014): 10–19.
3. J. C. Fairbank and P. B. Pynsent, “The Oswestry Disability Index,” Spine 25, no. 22 (2000): 2,940–52; I. Holm et al., “Measuring Self-Reported Functional Status and Pain in Patients with Chronic Low Back Pain by Postal Questionnaires: A Reliability Study,” Spine 28, no. 8 (2003): 828–33; M. Roland and J. C. Fairbank, “The Roland-Morris Disability Questionnaire and the Oswestry Disability Questionnaire,” Spine 25, no. 24 (2000): 3,115–24.
4. J. C. Fairbank and P. B. Pynsent, “The Oswestry Disability Index.”  
5. J. Tonosu et al., “The Normative Score and the Cut-Off Value of the Oswestry Disability Index (ODI),” European Spine Journal 21, no. 8 (2012): 1,596–602, doi: 10.1007/s00586-012-2173-7.
6. J. Tonosu et al., “The Normative Score and the Cut-Off Value of the Oswestry Disability Index”; U. Muller et al., “Condition-Specific Outcome Measures for Low Back Pain. Part I: Validation,” European Spine Journal 13, no. 4 (2004): 301–13, doi: 10.1007/s00586-003-0665-1.
7. J. Jin et al., “Factors Affecting Therapeutic Compliance: A Review from The Patient’s Perspective,” Therapeutics and Clinical Risk Management 4, no. 1 (February 2008): 269–86.
8. A. Okifuji and B. D. Hare, “The Association Between Chronic Pain and Obesity,” Journal of Pain Research 8 (2015): 399–408.

Definition of P-Value
P-value is short for probability value and is used in statistical calculations for hypothesis testing to indicate the data’s significance. Many factors play into a statistical test’s resultant p-value including sample size, power, and effect size. The p-value indicates the extent to which the compared data is different from each other. A low p-value (usually ≤0.05) indicates statistically significant differences, while those greater than 0.05 indicate any differences found are not statistically significant.The lower a statistical test’s p-value, the stronger the data conclusions become from a statistical standpoint because the probability of erroneous conclusions (that there actually are not differences between the compared groups despite the significant p-value) is lower. Thus, a p-value of ≤0.01 indicates there is only 1% or less chance of erroneous conclusions while a p-value of ≤0.001 indicates there is only a fraction of a percentage chance of the conclusion being wrong.

Niki Munk, PhD, LMT, is an assistant professor of health sciences at Indiana University’s School of Health and Rehabilitation Sciences, a Kentucky licensed massage therapist, a visiting research fellow with the Australian Research Centre in Complementary and Integrative Medicine, and mother of two young daughter-scientists. Munk’s research explores real-world massage therapy for chronic pain, trigger point self-care, massage for amputation-related sequelae, and the reporting and impact of massage-related case reports.