12 Sessions of Spinal Manipulation May Be Optimal for Chronic Low Back Pain
Twelve sessions of spinal manipulation appears to provide the best treatment effects in the chiropractic management of chronic low back pain with spinal manipulation, according to a prospective, open-label, randomized controlled trial published in The Spine Journal.
“Our fastidious randomized control trial shows that 12 sessions of spinal manipulation over 6 weeks for uncomplicated chronic low back pain is a reasonable care option,” said lead author Mitchell Haas, DC, Center for Outcomes Studies, University of Western States, Portland, OR. The study isolated the effects of spinal manipulation by controlling for a variety of potentially confounding factors, including the effects of time spent, touching and interacting with a patient, Dr. Haas said.
How Many Sessions Are Best?
The study was designed to determine the optimal number of spinal manipulation sessions needed to give the most efficient care with the best outcomes, factors that are of interest to patients, providers, payers, and policymakers, Dr. Haas said. In addition, the study was designed to determine the optimal number of spinal manipulation sessions to use in comparative effectiveness studies for the care of chronic low back pain.
Four hundred patients were randomized to 18 treatment sessions of spinal manipulative therapy (SMT) and/or focused light massage (LM) control as 3 sessions per week for 6 weeks as follows:
- 0 SMT plus 18 LM (n=100)
- 6 SMT plus 12 LM (n=100)
- 12 SMT plus 6 LM (n=100)
- 18 SMT plus 0 LM (n=100)
Each visit was 15 minutes in duration and consisted of application of a hot pack for 5 minutes, 5 minutes of the SMT or LM intervention, and 5 minutes of low-dose pulsed ultrasound. The primary outcomes were scores on the 100-point modified Von Korff pain intensity and functional disability scales evaluated at 12 and 24 weeks following the initial treatment. A between-group difference of at least 10 points was considered a clinically important effect for this study.
All of the SMT treatment arms showed a mean reduction of at least 20 points on both the pain and functional disability scales during the year-long, follow-up period. Most improvement was seen by the end of treatment at 6 weeks and was durable to the end of follow-up at 52 weeks. At the 12-week follow-up, the group that received 12 SMT visits showed the greatest difference in scores compared with the group that received LM alone (adjusted mean difference [AMD], 8.6 for pain scores and 7.5 for functional disability score; P=0.002 and P=0.011, respectively). A statistically significant relationship also was found between pain score and number of SMT sessions (linear dose-response effect). At the 24-week follow-up, SMT was not linked to clinically meaningful effects on pain or functional disability scores compared with LM alone.
“Modest” Treatment Effect Found
Assuming that a 10-point between-group difference in pain and function disability scores indicate a clinically meaningful effect, SMT had a “modest” treatment effect compared with LM alone at the 12-week follow-up. It also means the dose-response across all 4 treatment groups was modest, Dr. Haas said. A larger dose-response of SMT would be expected in a trial that omitted the extensive number of control visits, as light massage may have had a real treatment effect, Dr. Haas explained.
“If you look at all the studies that have been done on spinal manipulation, it’s pretty clear that spinal manipulation is a reasonable treatment option for the patient and is a viable option for physician referral,” Dr. Haas said. “In addition, spinal manipulation should be considered as a component of coordinated treatment plans within an integrative care setting,” he said.
A cost analysis from this trial found that SMT did not increase the cost of treatment for chronic low back pain when including the cost of lost productivity. “Thus, the modest benefit of SMT came at no additional cost from a societal perspective,” Dr. Haas said.
Clinical Implications of the Findings
“The clinical implications of this study are, in my opinion, straight forward: First, spinal manipulation (SMT) is one viable method for reduction of pain and improvement in physical function in patients experiencing chronic low back pain. It is not a miracle cure, but it does reduce pain and improve physical function,” commented Jan Hartvigsen, DC, PhD, Professor of Clinical Biomechanics and Musculoskeletal Research and Head of the Research Unit for Clinical Biomechanics at the University of Southern Denmark, Odense, Denmark.
“Second, previous studies have shown that an early favorable response to SMT is a good prognostic sign, ie people who experience significant pain relief already after 1-3 treatments will end up with a better result after a series of treatments than people who do not experience this early relief,” Dr. Hartvigsen said. “However, little has been known about the optimal total dose of SMT and the study by Hass et al begins to address that. We learn that there appears to be a ‘sweet spot’ around 12 treatments and that more is not necessarily better,” Dr. Hartvigsen said.
“High quality studies over the past 20 years have consistently shown that the most important factors in the transition from acute to chronic back pain, and in the persistence of pain are psychological and social,” Dr. Hartvigsen continued. “Factors like psychological distress, depression, job dissatisfaction, patient expectations for recovery, and ability to cope drive disability from back pain and also recovery to a larger extent than pain intensity when we study large cohorts of patients. This is not to say that pain relief is not important but spinal manipulation should probably be delivered in settings where these psychosocial issues are addressed and where patients with chronic back pain are helped to a more active lifestyle and where issues of work disability are addressed,” Dr. Hartvigsen said.
“In an era where frequently used options for pain relief for patients with chronic back pain are associated with low levels of evidence for effectiveness, major side effects and great cost (paracetamol, NSAID [nonsteroidal anti-inflammatory drugs], opioids and surgery, for example) it is important to explore and consider how beneficial, safe and low-cost interventions like spinal manipulation, patient education and exercise can be systematically put to use in health care systems. This study adds to the evidence base for one of these interventions by addressing the issue of dose,” Dr. Harvigsen concluded.
There is still much work left to be done in terms of determining optimal care for low back pain of mechanical origin, Dr. Haas said. For example, he suggested the need for studies on whether maintenance SMT can help prevent exacerbation of low back pain in the long term. In addition, “When you have a flare up, how do you minimize the intensity and duration of that episode?,” Dr. Haas said.