Research Review By Dr. Jeff Muir©

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Date Posted:

September 2019

Study Title:

Expectations influence treatment outcomes in patients with low back pain. A secondary analysis of data from a randomized clinical trial

Authors:

Eklund A, De Carvalho D, Pagé I, Wong A, Johansson MS, Pohlman K, Hartvigsen J, Swain M

Author's Affiliations:

Unit of Intervention and Implementation Research for Worker Health, The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Faculty of Medicine, Memorial University of Newfoundland, St. John’s NL, Canada; Department of Anatomy, Université du Québec à Trois-Rivières, Québec, Canada; Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong; Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; National Research Centre for the Working Environment, Copenhagen, Denmark; Research Institute, Parker University, Dallas, Texas, United States; Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark; Department of Chiropractic, Faculty of Science and Engineering, Macquarie University, Sydney, Australia; Institute for Musculoskeletal Health, School of Public Health, University of Sydney, Australia.

Publication Information:

European Journal of Pain 2019; 23(7): 1378-1389. doi: 10.1002/ejp.1407.

Background Information:

Low back pain (LBP) is a global health challenge, with high prevalence (1), recurrence rates (2) and healthcare costs (3), and is the condition associated with the highest societal burden in terms of years lived with disability (4). LBP exerts its influence at the societal level but also at the individual level, with both psychological and social consequences (5). As over 90% of LBP cases have no underlying spinal pathology (6), the use of a biopsychosocial approach, where physical/biological and psychosocial factors are addressed during care may be useful. This approach further recognizes that factors such as a positive attitude towards treatment and optimistic patient expectations can play an important role in treatment outcomes (7, 8).

Patient expectations of treatment are influenced by several factors, including past experiences with back pain, age, gender, demographic factors, education level, depression and fear (9-11). Past experiences are especially important and are often captured via ‘yellow flags’, which assess modifiable psychological risks factors important for evaluating both response to treatment and risk of symptom chronicity (12).

The goal of this study was to investigate the effect of patient expectation on short-term, subjective improvement in LBP in patients with recurrent/persistent LBP.

Pertinent Results:

From an initial pool of 2033 patients, 593 met all inclusion criteria and were included in this secondary analysis (63.5% female, average age: 43.4 years). 60% of patients reported associated leg pain, 66% reported comorbid neck or thoracic pain and 53.7% reported previous visits to a chiropractor for the same complaint.

LBP improvement at fourth visit in relation to expectations:
69.4% of patients were “definitely improved” by their fourth visit. The likelihood of patients reporting definite improvement by the fourth visit improved by an average of 9% for each unit increase on the expectations scale (RR = 1.09, 95% CI: 1.06-1.13). 74.2% of patients with a high expectation of success (> 5/10) reported definite improvement by the fourth visit, compared to 47.1% who began treatment with a low expectation of success (0-5/10). Patients with a high expectation of success had a 58% higher chance of reporting definite improvement by their fourth visit (RR = 1.58, 95% CI: 1.28-1.95).

Clinical Application & Conclusions:

This study demonstrated that short-term treatment outcomes in patients seeking treatment for LBP may be influenced by patients’ expectations for recovery, an observation that was not altered by psychological profile, pain intensity or self-rated health. Further, the authors determined that, based on grouping of patients based on MPI scores, having a “dysfunctional” psychological profile was also positively associated with LBP improvement at the fourth visit, compared to being an “adaptive coper” (this could explain a minor degree of the association between expectations and improvement). Patient expectations; however, remain the strongest and most clinically relevant predictive factor for patient-perceived LBP improvement. The authors therefore recommend that clinicians assess their patients for expectations for improvement early in their treatment, to help identify patients at risk of a poor prognosis.

Study Methods:

Study Design, Setting & Participants:
This study was a secondary analysis of data gathered during a randomized, controlled trial, prior to random allocation (13, 14). The original RCT investigated the effect of regular chiropractic ‘maintenance care’ treatments on symptom-based treatment for LBP (RRS Education reviewed this paper as well).

Patients were recruited from 40 chiropractic clinics in Sweden. Eligibility criteria included:
  • age 18-65;
  • recurrent LBP (> 1 episode in past 12 months), and/or
  • persistent LBP (> 30 days of pain in past 12 months).
Exclusion Criteria:
  • pregnancy,
  • serious spinal pathology,
  • prior chiropractic treatment in the last 3 months, or
  • patients who did not pay for treatment themselves.
Data collection included: a baseline questionnaire recording sociodemographic data, LBP history, comorbid pain, psychological profile, expectations for improvement, self-rated health, general health, type of work, pain medication use and previous chiropractic treatment history. At their fourth visit, patients were asked about their subjective improvement. If a “definitive improvement” was noted at the second or third visit, the fourth visit questionnaire was administered at that visit.

Recorded variables included: patient’s expectations for treatment (to help), ranked from 0 (no chance) to 10 (very likely); and subjective improvement at fourth visit, ranked from 1 (definitely worse) to 5 (definitely improved). Psychological profiles were assessed using the Swedish version of the West Haven-Yale Multidimensional Pain Inventory (MPI) at baseline. LBP intensity was measured on a scale from 0 (no pain) to 10 (worst pain imaginable). Self-rated health was measured using the EQ5D quality of life survey.

Poisson regression models were used to determine the predictive effect of patient expectations on short-term improvement. Both univariate and multivariate analyses were utilized, with the variable with the highest p-values excluded in a stepwise analysis until the model included only those variables with a statistically significant p-value.

Study Strengths / Weaknesses:

Strengths:
  • A large sample size of practice-based patients was included.
  • Clinically-relevant outcomes were included in the analysis.
  • A robust statistical analysis was undertaken.
Weaknesses:
  • Dichotomization of the expectation variable (i.e. > 5/10 equated to a high expectation) resulted in the majority of data points being in the upper interval of the scale (meaning, some information may have been lost). The authors stated this was done to avoid classification bias of the true expectation, which is reasonable.
  • The time between initial and fourth visit was not standardized.
  • Treatment was left to the discretion of the treating chiropractor (i.e. not standardized).

Commentary from Dr. Andreas Eklund (lead author):

As a clinician, my primary aim is to maximize the benefit patients receive from care and a constant question in my mind relates to evidence based practice (EBP). To what extent do I rely on each of the components: evidence, clinical experience and patient preferences?

Of course, it depends on the available evidence, the extent of my own experience and the patient preferences in each individual case, while clinical outcomes are continually evaluated and the care package adapted accordingly. This is a complex and dynamic process that is centered around the patient’s needs and limitations.

Patient centered care is the hallmark of healthcare today and on everyone’s mind. An important part of the patient centered approach is to consider patients values, beliefs and expectations when deciding on care pathways and interventions. For a common condition like low back pain where multiple (equally effective) treatments are available, the need to tailor and adapt the treatment package to the patient’s individual beliefs and expectations becomes even more important from an EBP perspective.

Patient expectations have been shown to be an important factor that modify the effect of interventions across different populations, conditions and treatments. Whether this is related to contextual effects or previous experience is difficult to tease out. Irrespective, as a clinician it is important to understand, adapt to and in some cases manage expectations to maximize the potential benefit from care.

For the interested clinician, this paper may add important pieces to the EBP puzzle when it comes to understanding the value of patient expectations in a patient centered model. After all, the Chiropractic profession is firmly grounded in a holistic bio-psycho-social framework and I personally believe the ability to listen, understand and relate to my patients is the most important clinical skill I have developed during my 17 years in practice. As complex social beings, there are few things more important than being seen, heard and understood.

Andreas Eklund, MSc (Chiro), PhD, CARL Fellow (Chiropractic Academy for Research Leadership). Unit of Intervention and Implementation Research for Worker Health, The Institute of Environmental Medicine (IMM) Karolinska Institutet, Stockholm, Sweden.

Additional References:

  1. Vassilaki M & Hurwitz EL. Insights in public health: perspectives on pain in the low back and neck: global burden, epidemiology, and management. Hawaii J Med Public Health 2014; 73(4): 122-126.
  2. Von Korff M & Saunders K. The course of back pain in primary care. Spine 1996; 21(24): 2833-2837; discussion 2838-2839.
  3. Ekman M, Johnell O & Lidgren L. The economic cost of low back pain in Sweden in 2001. Acta Orthop 2005; 76(2): 275-284.
  4. Hoy D et al. The global burden of low back pain: estimates from the Global Burden of Disease 2010 study. Ann Rheum Dis 2014; 73(6): 968-974.
  5. MacNeela P, Doyle C, O'Gorman D et al. Experiences of chronic low back pain: a meta-ethnography of qualitative research. Health Psychology Review 2015; 9(1): 63-82.
  6. Krismer M, Van Tulder M, Low Back Pain Group of the Bone and Joint Health Strategies for Europe Project. Strategies for prevention and management of musculoskeletal conditions. Best Pract Res Clin Rheumatol 2007; 21(1): 77-91.
  7. Mondloch MV, Cole DC & Frank JW. Does how you do depend on how you think you'll do? A systemic review of the evidence for a relation between patients' recovery expectations and health outcomes. Canadian Medical Association Journal 2001; 165(10): 1303-1303.
  8. Gross DP & Battie MC. Work-related recovery expectations and the prognosis of chronic low back pain within a workers' compensation setting. Journal of Occupational and Environmental Medicine 2005; 47(4): 428-433.
  9. Goldstein MS, Morgenstern H, Hurwitz EL & Yu F. The impact of treatment confidence on pain and related disability among patients with low-back pain: results from the University of California, Los Angeles, low-back pain study. Spine J 2002; 2(6): 391-399; discussion 399-401.
  10. Goossens ME, Vlaeyen JW, Hidding A et al. Treatment expectancy affects the outcome of cognitive-behavioral interventions in chronic pain. Clinical Journal of Pain 2005; 21(1): 18-26; discussion 69-72.
  11. Gepstein R, Arinzon Z, Adunsky A & Folman Y. Decompression surgery for lumbar spinal stenosis in the elderly: preoperative expectations and postoperative satisfaction. Spinal Cord 2006; 44(7): 427-431.
  12. Nicholas MK, Linton SJ, Watson PJ et al. Early Identification and Management of Psychological Risk Factors ("Yellow Flags") in Patients With Low Back Pain: A Reappraisal. Physical Therapy 2011; 91(5): 737-753.
  13. Eklund A, Axen I, Kongsted A et al. Prevention of low back pain: effect, cost-effectiveness, and cost-utility of maintenance care - study protocol for a randomized clinical trial. Trials 2014; 15(1): 102.
  14. 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.