Characteristics and Outcomes of Patients Receiving Physical Therapy for Low Back Pain with a Nociplastic Pain Presentation: A Secondary Analysis

Abstract

Introduction. Individuals with low back pain (LBP) may be classified based on mechanistic descriptors, such as a nociplastic pain presentation (NPP). The purpose of this secondary analysis was to examine the frequency and characteristics of patients with a NPP referred to physical therapy with LBP. Additionally, we characterized patients with LBP meeting the criteria for NPP by demographic, clinical, psychological, and pain sensitivity variables. Finally, we examined short- and long-term clinical outcomes in patients with a NPP compared to those without a NPP. Materials and Methods. Patients referred to physical therapy for LBP completed the Patient Self-report Survey for the Assessment of Fibromyalgia. Participants were categorized as “LBP with NPP” or “LBP without NPP” based on the threshold established in this measure. A rank sum test examined for differences in pain-related psychological factors and pressure-pain threshold between groups. Next, a Friedman test examined if LBP intensity and disability trajectories differed by groups at one and six months after initiation of physical therapy. Results. 22.2% of patients referred to physical therapy for LBP met the criteria for a NPP. Patients with a NPP reported significantly greater disability, pain catastrophizing, depression, anxiety, and somatization compared to individuals without a NPP ( p < 0.05 ). Pressure-pain threshold did not differ between groups ( p > 0.05 ). Individuals with LBP with a NPP demonstrated nonsignificant, small to medium reductions in pain and disability at one and six months. Individuals experiencing LBP without a NPP demonstrated significant reductions in pain and disability in the short- and long term. Conclusion. Patients with LBP with a NPP displayed greater negative pain-related psychological factors but similar pain sensitivity compared to LBP without NPP.

The Association Between the Patient Self-Report Survey for the Assessment of Fibromyalgia with Pain Sensitivity and Psychological Factors in Individuals with Musculoskeletal Pain

“…A preliminary study from our research group found patients receiving physical therapy for low back pain categorized as having symptoms consistent with fibromyalgia (and therefore a nociplastic pain presentation) based on this questionnaire had significantly higher depression, catastrophizing, and anxiety. 25 The results from these separate studies from our group are consistent. The results of this study are further supported in the work by Brummett et al 40 and Aoyagi et al 13 Patients with spine pain who have a fibromyalgia-like phenotype have significantly higher levels of depression, 13 , 40 anxiety, 13 , 40 and catastrophizing.…”

“… 38 A score of 13 or higher on this measure indicates fibromyalgia, 38 but this threshold has been used to categorize a nociplastic pain presentation in musculoskeletal pain research. 13 , 25 , 40 Participants also report if there is another disorder that could potentially explain these symptoms and if the symptoms have been present for over 3 months.…”

“… 25 When applying the threshold from this questionnaire to distinguish patients with low back pain with and without a nociplastic pain presentation, catastrophizing and depression are significantly higher in those with a nociplastic pain presentation. 13 , 25 , 40 …”

“…11,23 Psychological factors, including emotional distress and depression, are predictors in the transition to persistent musculoskeletal pain 7 and a risk factor for chronic widespread pain. 24 In individuals with low back pain who have a nociplastic pain presentation, negative pain-related psychological factors 25 and catastrophizing 26 are significantly higher. Elevated negative pain-related psychological factors are also present in patients with nociplastic pain conditions, such as fibromyalgia.…”

“…34,35,37 The Patient Self-Report Survey for the Assessment of Fibromyalgia (also called the 2011 Fibromyalgia Survey) was originally developed as a method for identifying the prevalence of fibromyalgia in population-based studies 38,39 and has been used to categorize a nociplastic pain presentation in musculoskeletal pain populations. 13,25,40 The Patient Self-Report Survey for the Assessment of Fibromyalgia measures the severity of fibromyalgia-related symptoms and number of pain locations. Given that fibromyalgia is generally considered a primary example of a nociplastic pain condition, a questionnaire measuring the severity of fibromyalgia symptoms has the potential to serve as a proxy measure for identifying clinically important subgroups of patients with nociplastic pain affecting the musculoskeletal system.…”