Research Review By Dr. Joshua Plener©


Download MP3

Date Posted:

December 2022

Study Title:

Spinal manipulative therapy in older adults with chronic low back pain: an individual participant data meta‑analysis


Jenks A, de Zoete A, van Tulder M et al.

Author's Affiliations:

Faculty of Science, Department of Health Sciences, Vrije Universiteit, Amsterdam, The Netherlands; Faculty of Movement and Behavioral Sciences, Vrije Universiteit; Department of Physiotherapy and Occupational Therapy, Aarhus University Hospital, Denmark

Publication Information:

European Spine Journal 2022; 31:1821-1845

Background Information:

In randomized controlled trials assessing low back pain, older adults are often underrepresented (or simply excluded!). Studies have demonstrated that low back pain in older adults often lasts longer than 3 months and is usually undertreated or (unfortunately) mismanaged (1-3). As a result, it is important to identify treatment options that are safe and effective for older adults to help reduce the burden of disease (4). Guidelines advocate for non-pharmacological treatments for low back pain (5). Specifically, spinal manipulative therapy (SMT) is used by many professions and systematic reviews suggest that it is an effective intervention for the reduction of pain and improvement in function (6, 7).

One approach to examine the effectiveness of SMT in older adults with low back pain is to perform an individual participant data meta-analysis. Compared to traditional meta-analyses, the individual data for each participant is accessed, allowing researchers to select specific individuals and correct for baseline covariates which may influence the results, enabling a more precise and thereby potentially more valid calculation of the effect estimates (8).

The objective of this individual participant data meta-analysis is to assess the effectiveness of SMT compared to other interventions recommended by guidelines at 1, 3, 6 and 12-month follow-ups in older adults with chronic low back pain.

Pertinent Results:

Ten RCTs consisting of 786 participants aged 55 years and over were included in the individual participant data meta-analysis. 403 participants were randomized to the SMT group and 383 were randomized to the comparison group.

Of the 10 RCTs, 9 compared SMT to exercise therapy and one evaluated the effects of SMT compared to standard medical care. Sample sizes ranged from 5 to 220 with an average age of 63 years, with 58.4% of participants being women.

There is moderate quality evidence that SMT has similar benefits to recommended interventions at all time points for pain (remember, the comparison treatment was mostly exercise, which is also known to be beneficial!). The average difference for SMT compared to other interventions is -2.56 after 1 month on a scale of 0-100, and those effects appear similar over the subsequent 12 months.

There is also moderate quality evidence that SMT has similar benefits to other recommended interventions for functional status. This was maintained at all time points that were assessed.

Clinical Application & Conclusions:

This study suggests that SMT has similar effects to recommended interventions, mainly exercise therapy in the short, intermediate, and long term. This is the first individualized participant data meta-analysis to examine the effects of SMT in older adults with low back pain. Older adults represent a growing and very important patient population in the spine pain realm, where the potential for positive impact is huge for our profession!

There are limitations in the included trials, such as not assessing adverse events, thereby not providing a complete picture of benefit vs risk. Research should assess adverse events for SMT compared to other treatments to determine its relative risk, however major adverse events are likely to be very rare. Future research should focus on identifying which older adults are best suited for SMT, after accounting for lifestyle factors, comorbidities, and their level of physical activity.

Editor’s note: We know the burden of spinal pain is both growing and concerning in older adults. The literature also shows us that older patients with chronic low back pain are more likely to be mismanaged and experience more severe levels of pain and disability. This study adds support to our expanding knowledge base regarding the effectiveness of SMT for these older patients, and should also serve as a reminder of the effectiveness of exercise (which was the most common comparison treatment in the studies analyzed in this paper). The combination of SMT and exercise can be a powerful way to help older patients manage pain and modulate functional decline due to low back pain – both of which are highly desirable outcomes!

Study Methods:

The Individual Participant Data database includes raw data from 21 RCTs published between 2000 and 2018. This data base was updated to include any other articles published between 2018 and June 2020.

Trials examining the effects of SMT versus recommended therapies in an older age population with chronic low back pain were included. The inclusion criteria consisted of patients aged 55 and older with chronic low back pain with or without leg pain defined as > 12 weeks of duration and not attributable to a recognizable, known, specific pathology. Furthermore, trials from primary or secondary care settings were included and when a mixed population was involved, only participants with > 12 weeks of low back pain were included.

The exclusion criteria were:
  • Inadequate randomization procedures
  • Patients with low back pain and other conditions such as pregnancy or post-operative patients
  • Studies that tested the immediate effect of a single treatment only
  • Studies that compared the effects of a multimodal therapy including SMT to another therapy or any other study design whereby the contribution of SMT could not be isolated
  • Studies that included patients with a contraindication to SMT
Risk of bias was assessed using the Cochrane Back and Neck group criteria, which is composed of 13 criteria used to identify selection bias, performance bias, attrition bias, detection bias, and selective outcome reporting bias.

The primary outcomes of interest were pain and back-specific functional status. All outcomes were pooled, and all pain scores were converted to a pain scale ranging from 0-100, where a higher score indicates more pain. For functional status measures, individual scores were converted into Z-scores for each separate time point. Analyzing the Z-scores resulted in standardized mean differences, which were then converted to a mean difference for the 24-point Roland Morris Disability Questionnaire for ease of interpretation.

All analyses were based on the intention-to-treat principle with the primary analyses consisting of one-stage individual participant data meta-analysis at 4, 13, 26 and 52 weeks of follow-up. These follow-ups were chosen as they are standard follow-up time points for the treatment of low back pain (6).

To examine whether RCTs included in this individual participant data meta-analysis were presentative of all RCTs assessing the effects of SMT in older adult patients, a sensitivity analysis was done.

The quality of evidence for each outcome was evaluated using the GRADE approach and the clinical relevance was assessed as small, medium or large effect (9).

Study Strengths / Weaknesses:

  • An individual patient data meta-analysis is a very high level of research investigation.
  • All trials provided data on pain and functional status for all time points.
  • Sensitivity analyses confirmed the findings, suggesting the effect estimates were robust.
  • The findings of this study are important but need to be contextualized, as other important information wasn’t assessed such as adverse events.
  • Two-thirds of participants were between the ages of 55 and 65, so the results should be interpreted with caution when extrapolating to adults older than 65.

Additional References:

  1. Paeck T, Ferreira ML, Sun C et al. Are older adults missing from low back pain clinical trials? A systematic review and meta-analysis. Arthritis Care Res (Hoboken) 2014; 66: 1220–1226.
  2. Hartvigsen J, Frederiksen H, Christensen K. Back and neck pain in seniors-prevalence and impact. Eur Spine J 2006; 15: 802–806.
  3. American Geriatrics Society Panel on Pharmacological Management of Persistent Pain in Older Persons? why is this repeated and where are the authors? Pharmacological management of persistent pain in older persons. J Am Geriatr Soc 2009; 57: 1331–1346.
  4. Pohontsch NJ, Heser K, Loffler A et al. General practitioners’ views on (long-term) prescription and use of problematic and potentially inappropriate medication for oldest-old patients—a qualitative interview study with GPs (CIMTRIAD study). BMC Fam Pract 2017; 18: 22.
  5. Sibbritt DWAJ. Back pain amongst 8910 young Australian women: a longitudinal analysis of the use of conventional providers, complementary and alternative medicine (CAM) practitioners and self-prescribed CAM. Clin Rheumatol 2010; 29(1): 25-32.
  6. Rubinstein SM, de Zoete A, van Middelkoop M et al. Benefits and harms of spinal manipulative therapy for the treatment of chronic low back pain: systematic review and meta-analysis of randomised controlled trials. BMJ 2019; 364: l689.
  7. Chiarotto A, Deyo RA, Terwee CB et al. Core outcome domains for clinical trials in non-specific low back pain. Eur Spine J 2015; 24: 1127–1142.
  8. Tierney JF, Vale C, Riley R et al. Individual participant data (IPD) meta-analyses of randomised controlled trials: guidance on their use. PLoS Med 2015; 12: e1001855.
  9. Furlan AD, Malmivaara A, Chou R et al. 2015 Updated method guideline for systematic reviews in the Cochrane back and neck group. Spine 2015; 40: 1660–1673.

Contact Tech Support  Contact Dr. Shawn Thistle
RRS Education on Facebook Dr. Shawn Thistle on Twitter Dr. Shawn Thistle on LinkedIn Find RRS Education on Instagram RRS Education (Research Review Service)