Research Review By Dr. Kent Stuber©

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Date Posted:

June 2020

Study Title:

The Nordic maintenance care program: maintenance care reduces the number of days with pain in acute episodes and increases the length of pain free periods for dysfunctional patients with recurrent and persistent low back pain - a secondary analysis of a pragmatic randomized controlled trial

Authors:

Eklund A, Hagberg J, Jensen I, et al.

Author's Affiliations:

Karolinska Institute, Institute of Environmental Medicine, Unit of Intervention and Implementation Research for Worker Health Institute for Regional Health Research, Stockholm, Sweden; University of Southern Denmark Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark.

Publication Information:

Chiropractic & Manual Therapies 2020; 28: 19.

Background Information:

Prevention of spinal pain and related disability at the secondary (preventing chronicity and recurrence) and tertiary (preventing progression of a condition) levels is an important issue in musculoskeletal health, particularly when considering the worldwide burden of spinal conditions. Maintenance care (MC) is an approach to chronic and recurrent spinal pain that is often utilized by chiropractors. MC involves appointments typically scheduled on a regular basis and most often includes the provision of manual therapy (like spinal manipulation), exercise prescription and other ancillary treatments and/or lifestyle advice. Much of the research on MC has been observational and qualitative, although a few RCTs have been produced in the past decade (1). The majority of the highest quality research on MC has come from the Nordic Maintenance Care Program, which has done an admirable job of characterizing what maintenance care is and looking at its effectiveness (we have reviewed this work – check the “Maintenance Care” section of the RRS Education database) (2).

In a secondary analysis of their original RCT (described in Methods section below), they already found that psychological sub-groups defined by the Swedish version of the West Haven-Yale Multidimensional Pain Inventory (MPI-S) could identify both those who would and would not respond to MC (3). More specifically, the MPI-S can identify the following groups:
  1. Adaptive copers (AC) – characterized by low pain severity, low interference with everyday life, low life distress, a high activity level and a high perception of life control
  2. Interpersonally distressed (ID) – tend to perceive negative responses by spouses or significant others to their pain behavior and complaints, for example not being supportive/helpful, and expressing irritation, frustration and anger
  3. Dysfunctional (DYS) – characterized by high pain severity, marked interference with everyday life, high affective distress, low perception of life control and low activity levels
Analysis of the original data based on these identifiable sub-groups revealed that adaptive copers (AC) actually did worse under MC, while the dysfunctional (DYS) sub-group benefitted most from MC. This suggests we as clinicians should attempt to select patients to receive MC who have recurrent or persistent LBP, responded well to initial care and have a dysfunctional psychological profile.

To further our understanding of the nature of how patients may benefit from MC (specifically whether it is a matter of treatment dose or timing), the authors conducted this further secondary analysis of their original trial, focusing on pain trajectories of patients before and after visits or the first visit in a new treatment period; time to/risk of a new episode following the first recovery period; and the length of pain-free periods and total number of pain-free weeks.

Pertinent Results:

The MC and control groups were typically similar to one another at baseline. With respect to pain trajectory, the control group saw days per week with bothersome back pain ramping up in the weeks before a visit and peaking in the week of a visit more so than the MC group, which had a relatively flat trajectory in the weeks before and after a visit.

During the week of a visit, the average difference between the control group and MC group in days with bothersome pain per week was 0.46. The dysfunctional sub-group in particular showed a large difference between groups in terms of days/week with bothersome pain where the average difference between the control and MC groups’ dysfunctional sub-groups was 0.86 during the week of a visit. Such differences were not noted in the Adaptive Coper (AC) and Interpersonal Distressed (ID) sub-groups.

There were no important differences between groups in the risk of an episode following a recovery period. Furthermore, there were no large differences between the treatment groups in length of pain-free periods or number of pain free weeks, although the MC group on average had 2.6 more pain-free weeks than the control group throughout the year (this is itself a very desirable outcome!). However, the MC group’s dysfunctional sub-group had nearly 10 more pain-free weeks on average than the control group’s dysfunctional sub-group (an even more desirable outcome, for this specific set of patients). This trend was not noted in the AC or ID sub-groups.

Clinical Application & Conclusions:

This is an interesting and important study for clinicians and patients with recurrent or persistent low back pain, particularly those who appear to be early responders to chiropractic care. These results show us that such patients, and particularly those in the dysfunctional sub-group identified with the MPI-S, who attend on a PRN (versus scheduled MC) basis will show more of an increase in the number of days/week with bothersome back pain leading up to the week of a treatment, and after the treatment that number will fall again, showing a trajectory that is more of a curve. Conversely, those who receive MC showed a relatively flat trajectory, where the number of days per week with bothersome back pain does not rise noticeably in the weeks leading up to a visit or fall in the weeks after a visit. The average days/week with bothersome back pain were lower in the MC group than the control / PRN group throughout the period around a visit. So, in general, the MC appeared to produce a more stable clinical course than care that is on a per need basis, particularly for the dysfunctional subgroup.

From a clinical perspective, this study highlights the importance of considering our patients with recurrent or persistent back pain and their psychological characteristics related to their pain. The dysfunctional sub-group in particular (high pain severity, marked interference with everyday life, high affective distress, low perception of life control and low activity levels) appeared to benefit from MC as they had more pain-free weeks and typically fewer days/week with bothersome back pain than the dysfunctional sub-group in the control group. Identifying patients who would fit in the dysfunctional subgroup may therefore aid with treatment recommendations. The reasons for this aren’t known for certain and warrant further investigation.

Study Methods:

The original study (2) was a pragmatic, multicentre, investigator- and assessor-blinded randomized controlled trial with a two-arm parallel design, conducted as part of the Nordic Maintenance Care Program. Patients were recruited by 35 chiropractors in Sweden.

Using the PICO framework to assess this study:
  • Patients: Adults (18-65) with persistent or recurrent low back pain (LBP) with or without leg pain for > 30 days in the previous year and previous episodes of LBP. To be included, they had to respond favourably to chiropractic treatment by their 4th visit. 328 patients were randomized and data from 321 was ultimately analyzed.
  • Interventions: Maintenance Care (MC) – preventive treatment, clinician-controlled treatment frequency. Clinicians attempted to see patients for scheduled appointments before any significant return of LBP symptoms, within maximum 3-month intervals (that is, they were seen at intervals of 1-3 months apart). If symptoms returned, patients were treated until symptom resolution and then returned to MC. Treatment content and frequency were at the clinician’s discretion and to be tailored according to the needs of the patient.
  • Comparison: Control / PRN group – in this group the patients controlled treatment frequency, guided by their symptoms. Patients were encouraged to come in when symptoms returned, followed by treatment until maximum benefit was achieved. Again, the treatment content was at the clinician’s discretion and to be tailored according to the needs of the patient. Note – content of care was similar in both treatment arms – consisting of SMT, information/advice and soft tissue treatment.
  • Outcomes: Primary = number of days with bothersome LBP, tracked using weekly text messages. Secondary = disability (Roland Morris Disability Questionnaire), self-rated health (EuroQol 5), satisfaction, overall health, sick leave, perceived loss of productivity, and other treatments/medications used. The follow-up period for this study was 1 year.
This paper conducts a secondary analysis of the data (again, we reviewed the original paper on RRS Education – check the “Maintenance Care” section of the database). In this secondary analysis, the authors focused specifically on pain trajectories of patients before and after visits or the first visit in a new treatment period; time to/risk of a new episode following the first recovery period; and the length of pain-free periods and total number of pain-free weeks. Analyses were conducted for all participants and based on the psychological sub-groups to which they belonged according to the results on the MPI-S (West Haven-Yale Multidimensional Pain Inventory), which they completed at baseline (3 subgroups outlined above).

Study Strengths / Weaknesses:

The original study was a well-designed and considered pragmatic RCT, which was met with a lot of professional and media attention – this is certainly a popular topic amongst chiropractors! Some might consider the pragmatic design to be a weakness, due to the lack of control over treating clinician behaviour, but this allows it to much more suitably reflect what actually happens in clinical practice and their design was informed by much of the previous Nordic Maintenance Care Program research. The 1-year follow-up would typically be good for an RCT of LBP patients, but with chronic and recurrent conditions, an even longer-term follow-up would be preferred. The main weakness of the study was the fairly large number of patients who dropped out during the inclusion processes, which led to the minimum number of patients required to adequately power the study not being included.

Additional References:

  1. Axen I, Hestbaek L, Leboeuf-Yde C. Chiropractic maintenance care - what’s new? A systematic review of the literature. Chiropr Man Ther. 2019; 27:63.
  2. Eklund A, Jensen I, Lohela-Karlsson M, et al. The Nordic maintenance care program: effectiveness of chiropractic maintenance care versus symptom-guided treatment for recurrent and persistent low back pain-a pragmatic randomized controlled trial. PLoS One.2018; 13(9): e0203029.
  3. Eklund A, Jensen I, Leboeuf-Yde C, et al. The Nordic maintenance care program: does psychological profile modify the treatment effect of a preventive manual therapy intervention? A secondary analysis of a pragmatic randomized controlled trial. PLoS One. 2019; 14(10): e0223349.