From acute to chronic back pain: Using linear mixed models to explore changes in pain intensity, disability, and depression

Cognitive flexibility training for chronic pain: a randomized clinical study

Introduction

Previous studies suggest an association between cognitive flexibility and development of chronic pain after surgery. It is not known whether cognitive flexibility can be improved in patients with chronic pain.

Objectives

This study tested whether a neurocognitive training program results in improved cognitive flexibility and pain in patients with chronic pain.

Methods

We conducted a single-center, prospective, randomized study investigating 5-week daily neurocognitive training in patients with chronic pain. Participants (n = 145) were randomized into neurocognitive training or care as usual, and they completed assessments at baseline, posttreatment, and 3 months. The treatment group was asked to spend 35 minutes daily completing a program with tasks on cognitive flexibility, memory, attention, and speed. The primary outcome was performance on the neurocognitive performance test (NCPT). Secondary outcomes included levels of pain interference and severity.

Results

At 5 weeks, the treatment group showed greater improvements on NCPT compared with the control group (d = 0.37); effect size was smaller at 3 months (d = 0.18). The treatment group reported lower pain severity at 5 weeks (d = 0.16) and 3 months (d = 0.39) than the control group, but pain interference was only lower at 3 months (d = 0.20).

Conclusions

Outcomes suggest that using neurocognitive training to modify cognitive flexibility in patients with chronic pain may improve pain severity. This study provided effect size estimates to inform sample size calculations for randomized controlled trials to test the effectiveness of neurocognitive interventions for the prevention and treatment of chronic pain.

Catastrophizing, Kinesiophobia, and Acceptance as Mediators of the Relationship Between Perceived Pain Severity, Self-Reported and Performance-Based Physical Function in Women with Fibromyalgia and Obesity

Purpose

Individuals with fibromyalgia and obesity experience significant impairment in physical functioning. Pain catastrophizing, kinesiophobia, and pain acceptance have all been identified as important factors associated with the level of disability. The objective of this study was to evaluate the role of pain catastrophizing, kinesiophobia, and pain acceptance as mediators of the association between perceived pain severity and physical functioning in individuals with fibromyalgia and obesity.

Patients and Methods

In this cross-sectional study, 165 women with fibromyalgia and obesity completed self-report questionnaires of perceived pain severity (ie, Numeric Pain Rating Scale), pain catastrophizing (ie, Pain Catastrophizing Scale), kinesiophobia (ie Tampa Scale of Kinesiophobia), pain acceptance (ie, Chronic Pain Acceptance Questionnaire), and perceived physical functioning (ie, Physical Functioning subscale of the Fibromyalgia Impact Questionnaire). In addition, a performance-based test (ie, 6-minute walking test) was conducted to assess objective physical functioning. Two multiple mediation analyses were performed.

Results

Pain acceptance and kinesiophobia mediated the relationship between pain severity and self-reported physical functioning. Pain catastrophizing and kinesiophobia mediated the relationship between pain severity and performance-based functioning.

Conclusion

Pain acceptance, kinesiophobia, and pain catastrophizing should be addressed in rehabilitative intervention to improve physical functioning. Interestingly, the subjective and objective aspects of physical functioning are influenced by different factors. Therefore, interventions for women with fibromyalgia and obesity should focus on factors related to both subjective and performance-based physical functioning.

Trajectories of disability in low back pain

Four recovery trajectories from low back pain were identified: high-stable (20.9%), high-decreasing (20.7%), medium-stable (29.9%), and low-decreasing (28.5%). Pain and depression predicted the high-stable trajectory.

Introduction:

Low back pain (LBP) is the leading course of years lived with disability. Unfortunately, not much knowledge exists about distinct trajectories of recovery from disability after LBP and their potential psychological predictors.

Objectives:

Hence, the aim of the present study was to identify trajectories of functional disability in LBP and their potential baseline psychological predictors.

Methods:

A 1-year consecutive cohort (N = 1048) of patients with LBP referred to the Spine Centre if they have not improved satisfactorily from a course of treatment in primary care after 1 to 2 months were assessed by self-report questionnaires at their first visit and at 6- and 12-month follow-up. Data from patients who responded to the Roland Morris Disability Questionnaire at least twice (N = 747) were used to assess trajectories of functional disability by Latent Growth Mixture Modeling. The following measures were used as baseline predictors of the trajectories: Pain Intensity Numerical Rating Scales, Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and Hospital Anxiety and Depression Scale.

Results:

Four distinct trajectories were identified: high-stable (22.0%), high-decreasing (20.4%), medium-stable (29.7%), and low-decreasing (27.9%). Using the low-decreasing trajectory as reference, baseline pain intensity, depressive symptoms, and pain-catastrophizing predicted membership of all 3 symptomatic trajectories. However, using the high-decreasing trajectory as reference, age, baseline pain intensity, and depression were predictors of the high-stable trajectory.

Conclusion:

In particular, the finding of a high-stable trajectory characterized by high levels of baseline psychological distress is of potential clinical importance because psychological distress may be targeted by cognitive behavioral therapeutic approaches.

An Ecological Momentary Assessment Study of Pain Intensity Variability: Ascertaining Extent, Predictors, and Associations With Quality of Life, Interference and Health Care Utilization Among Individuals Living With Chronic Low Back Pain

This ecological momentary assessment (EMA) study examined the extent of pain intensity variability among 140 individuals with chronic low back pain and explored predictors of such variability and psychosocial and health care utilization outcomes. Individuals completed momentary pain intensity reports (0-10 numeric rating scale) several times daily for two periods of seven consecutive days, one month apart. Participants also completed online questionnaires at baseline which tapped into pain characteristics, pain-related catastrophization, kinesiophobia, activity patterns, and depression and anxiety symptoms. Questionnaires assessing quality of life and health care utilization were administered online one month after completion of the last EMA report. Data were analyzed using linear hierarchical location-scale models. Results showed that pain intensity fluctuated over the course of a week as shown by an average standard deviation of 1.2. The extent of variability in pain intensity scores was heterogeneous across participants but stable over assessment periods. Patients' baseline characteristics along with psychosocial and health care utilization outcomes were not significantly associated with pain intensity variability. We conclude that pain intensity variability differs across patients yet correlates remain elusive. There is an important gap in our knowledge of what affects this variability. Future EMA studies should replicate and extend current findings. PERSPECTIVE: This study provides evidence indicating that there is substantial variability in momentary reports of pain intensity among individuals living with chronic low back pain. However, risk and protective factors for greater lability of pain are elusive as is evidence that greater pain intensity variability results in differential health care utilization.

Pain, disability, and lifestyle: Patients with complex regional pain syndrome compared to chronic musculoskeletal pain - a retrospective analysis

BACKGROUND

Complex regional pain syndrome (CRPS) is an orphan disease occurring as a complication after trauma. Due to its acute onset and the typical clinical presentation of the inflammatory and autonomous signs, it is an eye-catching chronic pain disease affecting also young and working people. In social media and the internet, high pain severity and unfavorable prognosis is often empathized.

METHODS

Here, we compared epidemiological, pain and lifestyle factors of 223 CPRS patients from the "ncRNAPain" cohort with 255 patients with chronic musculoskeletal pain (MSK). MSK patients were recruited at the beginning of a multimodal pain therapy program. We searched for factors predicting pain intensity.

RESULTS

Both chronic pain diseases affected women in middle age. Patients with MSK were more obese, drank more alcohol and were less educated (Pearson Chi-square Test or Mann-Whitney/U-Test). Both groups smoked more than healthy people in the OECD (Organization for Economic Cooperation and Development). Mann-Whitney/U-Test confirmed that CRPS patients did not have more severe pain and did not suffer more from pain-related disability than patients with MSK. CRPS patients also had less psychiatric comorbidities. Multiple linear regression analysis revealed that group assignment, depressive characteristics, body mass index, average alcohol consumption and smoking predicted higher pain ratings, while disease duration, anxiety symptoms or gender had no influence on pain intensity.

CONCLUSION

In summary our study supports a more optimistic view on pain in CRPS patients in comparison to MSK and identifies lifestyle factors which might contribute to the pathophysiology like smoking and drinking. Important next steps are the identification of CRPS patients at risk for chronification or - vice versa - with protective factors for pain resolution.

Exploring the origin of pain subclassification, with emphasis on low back pain: a scoping review

OBJECTIVE

This scoping review aimed to explore the different working definitions for the duration of acute, subacute, and chronic pain, with emphasis on low back pain, and to establish where these definitions originated and the rationale provided for the time frames used.

INTRODUCTION

From a global perspective, low back pain is a major social and economic problem. One of the most commonly used methods to stratify and manage low back pain is the traditional duration-based classification (acute, subacute, and chronic). Where these time points lie to differentiate these transitions continues to be debated within the scientific community, which may engender a degree of heterogeneity in study findings. Therefore, applying these findings to clinical practice may be somewhat challenging. This review encapsulates the historical origins of the different duration categories to provide an understanding of how these variations were derived.

INCLUSION CRITERIA

Studies that included participants with low back pain were the focus of this review. Sources that included children or other specific pain pathologies, such as cancer pain, were excluded. The main concept of interest was that the publication proposed an original definition of the duration of acute, subacute, or chronic low back pain. All study designs were included provided they gave a rationale for the duration that they used.

METHODS

The following databases were searched: MEDLINE, Embase, CINAHL, and PsycINFO, from the inception of each database until September 18, 2019. This review was limited to studies published in English. Two independent reviewers screened the retrieved articles against the eligibility criteria. Additional studies were searched from the reference lists of studies to find the original source. Some original sources overlapped with general pain duration literature. This led to a deviation from the scoping review protocol, which originally intended to focus on definitions of low back pain duration only. Data extraction was undertaken using a charting table developed specifically for the review objectives. The findings were presented using narrative synthesis.

RESULTS

Nineteen records were included in this review, and comprised three book chapters, four review articles, four articles that arose following pain expert group discussions, seven primary research studies, and a spinal guideline. Data were extracted from the included studies and categorized into four themes based on the origin of the classification of the duration. The themes included i) work/employment setting, ii) empirical studies, iii) expert reasoning, and iv) pathophysiological explanation.

CONCLUSIONS

This scoping review compiled the existing literature on the working definitions of the duration of acute, subacute, and chronic low back pain and found a wide variation. These ranged from seven days, 14 days, and seven weeks for the acute and subacute transition points, and seven weeks to three years for chronic low back pain. The duration definitions specifically referring to the general pain literature focused on three and/or six months for the transition to chronic. Better integration of reasoning between the identified themes could facilitate the establishment of more ideal duration definitions in the future. Although inconclusive, the definition most commonly cited, with most consensus, was three months for the transition to chronic low back pain.

Effects of Scrambler Therapy in Patients with Failed Back Surgery Syndromes and Factors Associated with Depression Affecting Pain before and after the Therapy

Objectives

To report the effects of scrambler therapy in patients diagnosed with failed back surgery syndromes and to analyze the factors affecting pain before and after the therapy.

Methods

This study included 26 patients (12 males and 14 females). The Oswestry Disability Index (ODI) and Brief Pain Inventory (BPI) before and after scrambler therapy, Beck Depression Inventory (BDI) score before therapy, and residual pain after therapy were assessed. The changes in the ODI, BPI, and residual pain before and after the therapy were analyzed using the Wilcoxon signed rank test. Spearman correlation analysis and Fisher's exact test were used to confirm the correlation between BDI and other factors. Multiple regression analysis was used to identify independent factors predicting residual pain, posttherapy ODI, and posttherapy BPI.

Results

The ODI changed from 25.69 ± 7.98 to 21.80 ± 9.41 (p < 0.05), and the BPI changed from 68.96 ± 18.00 to 61.62 ± 20.27 after scrambler therapy (p < 0.05). In addition, residual pain changed from 100 to 76.15 (p < 0.05). The BDI was negatively correlated with the duration of scrambler therapy and positively correlated with the initial OPD and BPI. In multiple regression analysis, residual pain was significantly correlated with the BDI (p < 0.05).

Conclusion

Scrambler therapy can be used to change the total scores of the ODI and BPI after 5 sessions of treatment. Also, residual pain was significantly related to the BDI. Clinical significance of depression severity on pain should be further investigated via prospective studies.

Exploring Changes in Activity Patterns in Individuals with Chronic Pain

This longitudinal study explored whether activity patterns change over time in a sample of 56 individuals with chronic musculoskeletal pain over a 15-day period. Once a day, the participants recorded their level of pain intensity and the degree to which they had engaged in several specific activity patterns. Linear mixed models with random coefficients were used to investigate the rate of change in the activity patterns. Age, sex, pain intensity, and pain duration were controlled. The results show that excessive persistence was the only self-reported activity pattern to show a linear change over the 15-day period. There was a decrease in excessive persistence, and this decrease was slower with higher levels of activity avoidance. However, no significant association was found between sex, age, pain intensity, and pain duration and excessive persistence at baseline or change over time. At baseline, a positive association was found between excessive persistence and pain avoidance, pain-related persistence, and pacing to reduce pain, and a negative association was found between excessive persistence and pacing to save energy for valued activities. This result suggests a profile characterized by alternate periods of high and low activity that, in this study, were unrelated to longitudinal changes in pain intensity.

A Reduction in Pain Intensity Is More Strongly Associated With Improved Physical Functioning in Frustration Tolerant Individuals: A Longitudinal Moderation Study in Chronic Pain Patients

OBJECTIVE

The onset and chronification of pain often has devastating consequences on the physical and mental functioning of individuals. Medical interventions are quite efficacious in reducing pain levels. However, changes in physical and mental health status after medical interventions are not proportional. In the past decades, rational/irrational beliefs, especially catastrophizing, have contributed to a better understanding of the pain experience. This study explores whether pain reduction efforts are more beneficial for individuals scoring high in rational thinking (moderation).

METHODS

The study design was longitudinal. Patients were assessed twice, 2 weeks prior to the start of medical treatment at the pain clinic and 6 months after. A total of 163 patients with heterogeneous pain (mostly low back and neck pain) participated in the study. Their mean age was 58.74 years (SD = 14.28) and 61.3% were female.

RESULTS

Overall, there was a reduction in pain intensity (t = 4.25, p < 0.001, d = 0.32). An improvement in physical functioning (t = 4.02, p < 0.001, d = 0.19), but not mental health (t = -0.66, p = 0.511, d = 0.11) was also observed. In the regression analyses, a decrease in pain intensity was moderately associated with improved physical health (β = 0.87, t = 4.96, p < 0.001, R 2 change = 0.177). This association was found to be moderated by frustration tolerance (β = -0.49, t = -2.80, p = 0.006, R 2 change = 0.039). Specifically, post hoc analyses indicated that changes in pain intensity only correlated with changes in physical health when patients reported high frustration tolerance levels (r = 0.47, p = 0.006, M = 7, n = 32), but not when patients were intolerant to frustration (r = 0.28, p = 0.078, M = 17, n = 41).

CONCLUSION

The results suggest that frustration tolerance may render adaptive by facilitating the positive effect that a reduction in pain intensity has on physical health status. The study findings are discussed in the context of personalized therapy with an emphasis on how to maximize the effectiveness of current interventions for pain.

An observational study of pain self-management strategies and outcomes: does type of pain, age, or gender, matter?

Background and aims Acute pain is differentiated from chronic pain by its sudden onset and short duration; in contrast, chronic pain is characterized by a duration of at least several months, typically considered longer than normal healing time. Despite differences in definition, there is little information on how types of self-management strategies or outcomes differ when pain is chronic rather than acute. Additionally, age and gender are thought to be related to types of strategies used and outcomes. However, strategies used and outcomes can be influenced by level of education, socioeconomic status, occupation, and access to the health care system, which can confound associations to type of pain, age or gender. The purpose of this study was to examine the association of strategies used for pain self-management and outcomes with type of pain, acute or chronic, age, or gender in a socioeconomically homogenous population, pharmacists. Methods Pharmacists with acute or chronic pain and a valid email completed an on-line questionnaire on demographic characteristics, pain characteristics, pharmacological and non-pharmacological strategies for managing pain, and outcomes (e.g. pain intensity). Univariate analysis was conducted by stratifying on type of pain (acute or chronic), then stratifying on gender (men vs. women) and age (younger vs. older). The a priori alpha level was 0.05. Results A total of 366 pharmacists completed the questionnaire, 212 with acute pain (average age=44±12.1; 36% men) and 154 with chronic pain (average age=53±14.0; 48% men). The chronic pain group reported substantially higher levels of pain before treatment, level of post-treatment pain, level of pain at which sleep was possible, and goal pain levels (effect sizes [ES's]=0.37-0.61). The chronic pain group were substantially more likely to use prescription non-steroidal anti-inflammatory medications (NSAIDS), opioids, and non-prescription pain relievers (ES's=0.29-0.80), and non-medical strategies (ES's=0.56-0.77). Participants with chronic pain also were less confident (ES=0.54) and less satisfied (ES=0.52). In contrast, there were no differences within either the acute or chronic pain groups related to gender and outcomes. In the acute pain group, there also were no gender differences related to management strategies. However, younger age in the acute pain group was associated with use of herbal remedies and use of rest. Within the chronic pain group, men were more likely to use NSAIDS and women more likely to use hot/cold packs or massage while older participants were more likely to use massage. Variability in post-treatment level of pain and percent relief was high in all groups (coefficient of variation=25%-100%). Conclusions The differences between acute and chronic pain were substantial and included differences in demographic characteristics, pain characteristics, management strategies used, and outcomes. In contrast, few associations between age and gender with either management strategies or outcomes were identified, although the variability was high. Implications When managing or researching pain management, acute pain should be differentiated from chronic pain. Because of the substantial variability within the gender and age groups, an individual approach to pain management irrespective of age and gender may be most useful.