Research Review By Dr. Ceara Higgins©

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Date Posted:

May 2019

Review Title:

Trajectories of Chiropractic Low Back & Neck Pain Patients

Studies Reviewed:

  1. STUDY #1: Wirth B, Riner F, Peterson C, et al. An observational study on trajectories and outcomes of chronic low back pain patients referred from a spine surgery division for chiropractic treatment. Chiropractic & Manual Therapies 2019; 27: 6-12.
  2. STUDY #2: Ailliet L, Rubinstein SM, Hoekstra T, et al. Long-term trajectories of patients with neck pain and low back pain presenting to chiropractic care: A latent class growth analysis. European Journal of Pain 2018; 22: 103-113.

Background Information:

Low back pain and neck pain are significant problems, causing high societal and economic burden despite the majority of cases having low levels of disability (4). Less than 20% of patients with LBP who see a surgeon are surgical candidates (5), making it important to have close collaboration between spine surgeons and non-surgical spine experts. As well, a mounting body of evidence supports viewing back and neck pain episodes as part of a lifelong pain experience rather than unrelated, separate events (3).

In STUDY #1 listed above, Wirth and colleagues aimed to study the trajectories and outcomes of patients with chronic low back pain (LBP) who were referred from the spine division of an orthopedic university hospital to a chiropractic teaching clinic in Switzerland for 12 months following the initiation of chiropractic treatment.

In STUDY #2, Ailliet and colleagues evaluated the trajectories of both neck pain (NP) and LBP to see if there were distinct groups of patients who followed different pathways over 6 months after beginning chiropractic treatment. More specifically, they wondered if individuals who fell into these groups showed distinct characteristics at baseline and follow-up, as well as whether NP and LBP followed the same trajectories.

Pertinent Results:

STUDY #1 (Wirth et al.):

67 patients with chronic LBP were recruited. The majority had been experiencing LBP for more than 1 year (all others more than 3, but less than 12 months) and 12 had undergone back surgery in the past. 31 Patients showed degenerative changes, including disc degeneration and stenosis, on MRI, however, aside from Modic type 1 changes and extensive zygapophyseal edematous changes, MRI changes are poorly correlated with LBP (6) and the degree of stenosis, while related to neurologic impairment, is unrelated to pain intensity and functional disability (1). 35% of these patients were taking analgesic medication at baseline and the treating chiropractor judged the general health of the patient to be good in 52%, average in 41%, and poor in 8%. The median number of chiropractic treatments received was 8, with 3 patients treated more than 20 times. 57% of patients completed their chiropractic treatment within 3 months, 79% within 6 months, and 85% within 12 months. 4 patients had received infiltrations within the past year, 38 had received physiotherapy, 4 had received massage therapy, 2 had received complementary medical treatments, and 6 had received multi-disciplinary therapy. 13 patients reported receiving other therapies while receiving chiropractic care and 13 reported stopping other therapies during the study, and no information was available for the other patients.

At baseline, mean NRS for current pain was 5.43 and mean BQ was 39.80. After 12 months, mean NRS for current pain decreased significantly to 4.05, with significant reductions showing after 6 months, while mean BQ showed significant reductions after 1 month, reducing to 29.00 after 12 months. Individual items on the BQ all significantly reduced within the first month of treatment with the exception of “depression”, which did not decrease until 3 months after the start of treatment, and “interference of back pain with ability to take part in recreational, social and family activities”, which did not decrease. After 1 week of treatment, 23% of patients reported overall improvement, 47% after 1 month, 56% after 3 and 6 months, and 44% reported overall improvements after 12 months. No association was seen between overall improvement and reduction in pain, but it was associated with reductions in bio-psycho-social impairment.

The overall improvement (Patient’s Global Impression of Change [PGIC] ratings of “better” or “much better”) was reported by about half of the patients from 1 month onward, and was associated with a significant reduction in bio-psycho-social impairment (BQ total score – although, the minimal clinically important change (MCIC) of 18 points was not reached), but not with pain reduction (NRS). These patients seemed to put less importance on reduction of pain intensity and more on reduced bio-psycho-social impairment with regards to self-perceived overall improvement. This serves to emphasize the importance of assessing bio-psycho-social impairment in chronic pain patients.

Although present pain did not show significant improvement before 6 months, average pain over the past week showed significant improvement within a month of starting treatment. Overall, average pain over the last week decreased by 29% and present pain decreased by 25% within the first 12 months, bringing both close to the 30% change considered clinically meaningful for chronic MSK pain. On average, this reduction in pain remained after 12 months, even though about 80% of the patients were no longer receiving chiropractic care.

STUDY #2 (Ailliet et al.): 153 patients with NP and 295 patients with LBP were included. Baseline characteristics of these patients were not significantly different. A 4-class model was developed for both NP and LBP.

For NP, these included:
  • Category 1: Recovering from mild baseline pain
  • Category 2: Recovering from high baseline pain
  • Category 3: Severe-chronic
  • Category 4: Recovering from mild baseline pain with a flare up
For LBP, these included:
  • Category 1: Recovering from mild baseline pain
  • Category 2: Recovering from high/severe baseline pain
  • Category 3: Moderate-chronic
  • Category 4: Slowly recovering from high baseline pain
The large majority of patients in both the NP and LBP groups fell into the “recovering from mild baseline pain” and “recovering from high/severe baseline pain” categories. They also followed similar trajectories over a 6-month period. In the NP group, 73.9% of patients fell into the “recovering from mild baseline pain” category, including those who started with mild levels of pain, showing a 30% reduction in pain within 3 weeks, and then remaining at very low levels of pain throughout the remainder of the 26-week follow-up period. 16.3% fell into the “recovering from high/severe baseline pain” category, including those who started with severe pain, showing a 30% reduction in pain within 6 weeks, and then remaining at very low levels of pain. 7.2% fell into the “severe-chronic” category, including those who had permanently high levels of pain, and 2.6% fell into the “recovering from mild baseline pain with a flare-up” category, including those who followed the same basic pattern as the “recovering from mild baseline pain” group and showed a flare-up around week 11 that lasted for 6 weeks, before reducing to very low levels of pain.

In the LBP group, 58.3% fell into the “recovering from mild baseline pain” category, including those patients who started with mild levels of pain, showing a 30% reduction in pain within 3 weeks, and then remaining at very low levels of pain throughout the 26-week follow-up period. 29.8% fell into the “recovering from high/severe baseline pain” category, including patients who started with moderate pain – they experienced a 30% reduction of pain within 4 weeks, and then remained at very low levels of pain. 6.5% fell into the “moderate-chronic” category, including patients with moderate to severe levels of pain, and 5.4% fell into the “slowly recovering from high baseline pain” category, including patients who started with severe levels of pain and experienced a 30% reduction of pain within 12 weeks.

This study shows that the majority of patients treated by chiropractors for nonspecific NP or LBP will get better, regardless of their baseline pain levels. The trajectories found by Ailliet et al. resemble those found by Axen et al. (2), yet differ greatly from other models. These differences may be explained by differences in the patient populations studied.

The trajectories for categories 3 and 4 in both the NP and LBP groups were based on data from a smaller number of patients. When you take into account dropouts or missing data, it is more difficult to reliably estimate the trajectory for these groups.

Clinical Application & Conclusions:

STUDY #1 (Wirth et al.): Co-management by surgeons and chiropractors is beneficial for patients with chronic LBP who have long-lasting pain, reduced general health, and high biopsychosocial impairment. This emphasizes the importance of close collaboration between the two disciplines in order to provide chronic LBP patients with optimal care.

STUDY #2 (Ailliet et al.): Most patients with NP or LBP presenting for chiropractic care show a symptom trajectory characterized by persistent or fluctuating pain of low to medium intensity. A minority of patients experience rapid complete recovery or develop chronic severe pain. The majority of patients with nonspecific NP or LBP being treated by chiropractors will get better, regardless of their pain levels at baseline. However, patients who do not respond within 6 weeks of beginning treatment do not seem to benefit, and care should be discontinued at that point.

Study Methods:

STUDY #1 (Wirth et al.):

These authors studied patients referred from the spine surgery division to the chiropractic teaching clinic. After giving written informed consent, all patients filled in a numeric rating scale (NRS) for present pain intensity and the Bournemouth Questionnaire (BQ), an outcome measure looking at bio-psycho-social outcomes, at baseline, 1 week after first treatment, and 1, 3, 6, and 12 months. At all points other than baseline, patients also completed the Patient’s Global Impression of Change (PGIC) scale and a seven-point Likert-scale ranging from extremes of “much worse” to “much better”. For this study only the top two categories (“much better” and “better”) were considered clinically relevant improvement. All questionnaires were administered by the treating chiropractor before the first treatment and then patients were given the option of completing them through email or phone at follow-ups.

STUDY #2 (Ailliet et al.):

These authors performed a prospective, multicentre, practice-based cohort study of patients with NP and/or LBP, recruited from 97 chiropractors in Belgium and the Netherlands. All patients received standard chiropractic care at the discretion of the chiropractor. Patients who expressed interest were contacted by a research assistant. Patients who enrolled in the study received weekly text messages on their mobile phones over the period of 1 year. Patients were accepted into the study if they were between 18 and 65, had not visited a chiropractor in the previous 6 months, had a chief complaint of NP and/or LBP with or without radiation, and had a basic understanding of the Dutch language in both reading and writing. Subjects with red flags or conditions considered as contraindications for spinal manipulative therapy (ex. severe osteoporosis, acute rheumatic episode, or extremely high blood pressure) were excluded from the study. Individuals with both NP and LBP were asked to decide which they wanted to report on at the beginning of the study.

Patients completed a baseline questionnaire in either a web-based or paper format prior to their initial chiropractic consult. This questionnaire collected information on sociodemographics, biomedical status, and psychological status. The Four-Dimensional Symptom Questionnaire was used to measure levels of distress, depression, fear, and somatization, and the Fear Avoidance Beliefs Questionnaire (FABQ) was used to measure the patient’s beliefs regarding the effect of physical activity and work on their spinal complaint. The Social Support Scale was administered and functional status was measured using either the Neck Disability Index (NDI) for patients with NP or the Oswestry Disability Index (ODI) for patients with LBP.

Each week for a year, four consecutive text messages, each containing a single question, were sent to patients, beginning the first Friday after they were accepted into the study and repeating every Friday for 52 weeks. Replies were given by answering each text message and the next text would not be sent until the answer to the previous one had been received. All answers were automatically included in a data file. The weekly questions were as follows:
  1. On a scale from 0 to 10 (with 0 = no pain and 10 = worst pain imaginable), how would you rate your NP/LBP today?
  2. On a scale from 0 to 10 (with 0 = not limited in activities of daily living (ADL) at all and 10 = extremely limited in ADL), how much are you limited in your ADL today?
  3. On a scale from 0 to 7, how many days did you experience NP/LBP in the past week?
  4. On a scale from 0 to 7, how many days were you limited in your ADL in the past week?
Based on the work of Ostelo and colleagues, a 30% change from baseline was considered clinically relevant. Patients scoring 1-3 on the NRS were considered to have mild levels of pain, those scoring 4-5, moderate levels of pain, and those scoring 5 and up, severe levels of pain. Where possible non-numerical answers were manually given a number (ex. “I have no pain” = 0). When this was not possible, they were coded as missing values. There were technical issues with the SMS tracking system leading to no text messages being sent for 6-9 weeks and thus a large number of missing values. However, as patients entered the study at different points over 4 months, they considered that missing data to be random. However, as there was a large amount of data missing in the last months, they were only able to use the data collected in the first 6 months. Finally, patients were classified into their best fitting class with the classes based on quadratic models and the clinical judgement of two of the authors, both with > 20 years of clinical experience.

Study Strengths / Weaknesses:

Strengths:

STUDY #2 (Ailliet et al.): The use of SMS for data collection allowed for more frequent data collection over a longer period of time, is inexpensive, and user-friendly.

Weaknesses

STUDY #1 (Wirth et al.):
  • No specific inclusion/exclusion criteria was outlined for the study (so, they just accepted all patients referred by the spine surgery division).
  • Treatment protocols were not outlined. Thus, it is impossible to know if all patients received standardized treatment or if the treatment was at the discretion of the treating chiropractor.
  • The authors drew conclusions based on a clinically significant decrease in total BQ scores, however, they failed to reach MCIC, calling those conclusions into question.
  • This study cannot be used to draw conclusions about the efficacy of chiropractic treatment in this population, as many patients received treatments other than chiropractic care. This study did not include a natural history control group, and patients who returned to orthopedic care were not tracked.
STUDY #2 (Ailliet et al.):
  • A large number of data points were missing due to problems with the SMS tracking system, which may have affected the data.
  • The size of the text message restricted the questions that could be asked.
  • About 20% of people who initially agreed to participate in the study failed to reply to the first set of questions, never entering the study.
  • Due to the possibility of technical problems, it may be necessary for a research assistant to closely monitor the process. This could compromise or eliminate the financial advantages for using text messages for data collection.

Additional References:

  1. Andrasinova T, Adamova B, Buskova J, et al. Is there a correlation between degree of radiographic lumbar spinal stenosis and its clinical manifestation? Clin Spine Surg 2018; 31(8): E403-E408.
  2. Axen I, Bodin L, Bergstrom G, et al. Clustering patients on the basis of their individual course of low back pain over a six month period. BMC Musculoskelet Disord 2011; 12: 99.
  3. Dunn K, Hestbaek L, Cassidy J. Low back pain across the life course. Best Pract Res Clin Rheumatol 2013; 27: 591-600.
  4. Hartvigsen J, Hancock MJ, Kongsted A, et al. What low back pain is and why we need to pay attention. Lancet 2018; 391: 2356-2367.
  5. Li AL, Yen D. Changes in referral pattern to a surgeon for low back pain: 1996 versus 2009. Healthc Q 2010; 13: 91-95.
  6. Ract I, Meadeb JM, Mercy G, et al. A review of the value of MRI signs in low back pain. Diagn Interv Imaging 2015; 96: 239-249.