February 2023

Which psychosocial factors are related to severe pain and functional limitation in patients with low back pain?

Correa LA, Mathieson S, Meziat-Fihlo N et al.

Rehabilitation Science Postgraduation Program, Centro Universitario Augusto Motta, Rio de Janeiro, Brazil; Institute for Musculoskeletal Health, Sydney School of Public Health, Faculty of Medicine and Health, The University of Sydney, Australia; Physical Therapy Department, Institutio Federal do Rio de Janeiro, Brazil

Brazilian Journal of Physical Therapy 2022; 26: 100413.

Low back pain (LBP) is the leading cause of disability worldwide (1). Psychosocial factors are known to negatively influence clinical outcomes in patients with LBP by contributing to pain development (2), pain aggravation (3, 4) and chronification (5). It is also established that patients with negative illness beliefs about LBP report higher pain intensity scores, longer pain duration and a higher level of disability (12, 14-16), while patients with positive beliefs (i.e. high self-efficacy) may have a better prognosis and treatment outcome (13). This study investigated the relationship between specific psychosocial factors and severe pain and functional limitation in patients with LBP.

A total of 472 participants were included in the study (308 females – 65%). The sample had an average age of 39.1 ± 14.7 years. 94.1% of participants presented with chronic pain, which was defined as experiencing pain for > 3-months. The average pain intensity rating for the sample was 4.7 ± 2.4-points on a 10-point Likert scale. The functional limitation score was an average of 5.9 ± 2.5/10.

The most prevalent psychosocial factors were anxiety (n = 375, 79.4%), catastrophizing (n = 271, 57.4%) and perceived stress (n = 269, 57.0%). Nearly all participants presented with maladaptive beliefs regarding low back pain. For instance, 82% of participants (n = 390) believed imaging of their lumbar spine was useful, while 76.1% (n = 129) believed that back trouble requires rest. Additionally, 27.4% of participants (n = 269) demonstrated low/moderate levels of positive expectation, while 36% of participants presented low/moderate self-efficacy (n = 170).

Patients with LBP and catastrophizing were 2.21 times more likely to have severe pain, and 2.72 times more likely to have severe functional limitations compared to those without catastrophizing symptoms. Patients with maladaptive beliefs that back trouble must be rested were 2.75 times more likely to present with severe pain and 1.72 times more likely to have severe functional limitation compared to patients without that maladaptive belief. Furthermore, patients with kinesiophobia were 3.34 times more likely to present with severe pain compared to participants without kinesiophobia. Finally, patients who are socially isolated were 1.98 times more likely to describe severe functional limitation.

A logistic regression was performed to evaluate the effects of psychological factors on severe pain and functional limitations. The model was statistically significant for pain and functional limitation, and explained 19% of the variance for pain, and 21% of the variance for functional limitation. The authors did not provide any information about what potential variables explained the rest of the variance for pain intensity and functional limitation. Social isolation was also associated with severity, despite the mechanism underpinning this association being poorly understood. The authors proposed that the notion of social isolation being linked to elevated pain severity and functional limitation may be a unique property to the Brazilian population, given the many factors leading to social isolation, including high rate of violence.

This study investigated the relationship between psychosocial factors, severe pain and functional limitation in patients with LBP. Patients who presented with kinesiophobia, catastrophizing and the maladaptive belief that rest is important in the context of LBP were more likely to describe severe pain intensity and functional limitations. Interestingly, and despite their high prevalence, anxiety, depression and perceived stress were not associated with severe LBP in this study.

The findings of this study are important for several reasons. Firstly, clinicians must not forget the fact that we are treating human beings. In that regard, we are responsible for developing a dialogue to identify which biomedical, psychological and cognitive factors might impact the person’s suffering. The presence of these psychological factors may necessitate clinicians to spend more time with patients to change maladaptive beliefs, and to build a personalized rehabilitation plan for that patient. These patients might be labeled as “more difficult to treat” or “non-compliant to care,” while in reality, they may need extra support to reduce distress prior to engaging in rehabilitation.

Use of patient reported outcome measure questionnaires such as the Tampa Scale of Kinesiophobia and the Pain Catastrophizing Scale can provide insightful information about these psychological variables and might allow clinicians to dive deeper into the patient’s perceptions and ideas about their pains. (For more information about the psychoemotional aspects of the pain experience, check our E-Seminar “All Aboard the Pain Train: A Chiropractor’s Guide to Chronic Pain”, which covers pertinent information about how to screen patients for these psychosocial variables, and more!)

Recruited participants were 18 years of age or older with a current self-reported LBP. LBP was defined as pain in the area between the 12th rib and gluteal folds. Patients with LBP could present with either localized pain, referred leg pain or widespread pain. Patients were excluded if they presented with specific neurological involvement (ex. cauda equina syndrome, spinal cord injury, CNS disease), trauma, spinal pathology (ex. tumours, fracture, infection), were pregnant, of if they disclosed a history of psychiatric illness, cancer, abdominal surgery within the last year, or lumbar spinal surgery at any time.

The researchers screened for anxiety, depression, perceived stress, stressful life events, social isolation, catastrophizing, kinesiophobia, maladaptive beliefs, functional limitations, and pain intensity. A range of social, demographic, mental health, cognitive and lifestyle characteristics were also evaluated. Each included participant was evaluated once via face-to-face interview or via online survey. The questionnaires utilized in this study were the Brief Screen Questions (BSQ), Brief Psychological Screening Questions, Stress-Producing Life Events Questionnaire, Back Beliefs Questionnaire, Pain Attitudes and Beliefs Scale for Physiotherapists, Modified Back Beliefs Questionnaire, and the Patient Specific Functional Scale. Pain intensity was measured using the Brief Pain Inventory, which asks the patient to provide their current, least, worst, and average pain ratings over a 24-hour period on a 0-10 Likert scale.

The primary outcomes for the study were pain intensity and functional limitation. Specifically, the primary outcomes were dichotomized into severe (values ranging between 7-10/10), and mild-moderate (values below 7/10). Psychosocial factors were also dichotomized as either “present” or “absent.”

Strengths:
The authors utilized a number of tools to provide them with a large cross-section of psychological variables to measure. The authors also utilized a patient interview to gather data about the psychological variables, rather than only using questionnaires.

Weaknesses:
First, the cross-sectional study design limited the authors’ ability to infer causality. Second, the majority of included subjects suffered from chronic back pain, and as such the results of this study may be poorly generalizable to the acute pain population. Finally, maladaptive beliefs data were based on self-report and non-validated questions in this specific Brazilian population.