Report of the National Institutes of Health Task Force on Research Standards for Chronic Low Back Pain

Objectives

Despite rapidly increasing intervention, functional disability due to chronic low back pain (cLBP) has increased in recent decades. We often cannot identify mechanisms to explain the major negative impact cLBP has on patients' lives. Such cLBP is often termed nonspecific and may be due to multiple biologic and behavioral etiologies. Researchers use varied inclusion criteria, definitions, baseline assessments, and outcome measures, which impede comparisons and consensus. The purpose of this article is to disseminate the report of the National Institutes of Health (NIH) task force on research standards for cLBP.

Methods

The NIH Pain Consortium charged a research task force (RTF) to draft standards for research on cLBP. The resulting multidisciplinary panel developed a 3-stage process, each with a 2-day meeting.

Results

The panel recommended using 2 questions to define cLBP; classifying cLBP by its impact (defined by pain intensity, pain interference, and physical function); use of a minimal data set to describe research subjects (drawing heavily on the Patient Reported Outcomes Measurement Information System methodology); reporting “responder analyses” in addition to mean outcome scores; and suggestions for future research and dissemination. The Pain Consortium has approved these recommendations, which investigators should incorporate into NIH grant proposals.

Conclusions

The RTF believes that these recommendations will advance the field, help to resolve controversies, and facilitate future research addressing the genomic, neurologic, and other mechanistic substrates of cLBP. Greater consistency in reporting should facilitate comparisons among studies and the development of phenotypes. We expect the RTF recommendations will become a dynamic document and undergo continual improvement.     

Definitions of Chronic Low Back Pain From a Scoping Review,and Analyses of Narratives and Self-Reported Health of Adults With Low Back Pain

Among those with low back pain (LBP), individuals with chronic LBP (CLBP) face different treatment recommendations and incur the majority of suffering and costs. However, the way CLBP has been defined varies greatly. This study used a scoping review and qualitative and quantitative analyses of data from LBP patients to explore this variation. CLBP in most recent randomized controlled trials (RCTs) was defined by duration of pain, most commonly ≥3 months. However, individuals with LBP most often define CLBP by frequency. CLBP has also been defined using a combination of duration and frequency (16% of RCTs and 20% of individuals), including 6% of recent RCTs that followed the NIH Pain Consortium research task force (RTF) definition. Although not a defining characteristic of CLBP for individuals, almost 15% of recent RCTs required CLBP to have a healthcare provider diagnosis. In our LBP sample moving from ≥3 months to the RTF definition reduced the CLBP group size by 25% and resulted in a group that used more pain management options and reported worse health across all outcome measures. A pain duration definition offers ease of application. However, refinements to this definition (eg, RTF) can identify those who may be better intervention targets.PerspectiveThis article presents the definitions used for CLBP by researchers and individuals, and the impact of these definitions on pain management and health outcomes. This information may help researchers choose better study inclusion criteria and clinicians to better understand their patients’ beliefs about CLBP.     

悬吊训练对慢性腰痛患者运动皮质区神经网络的影响

目的:研究悬吊训练对慢性腰痛(chronic low back pain,cLBP)患者运动皮质区神经网络的影响.方法:招募20例cLBP患者和与之年龄等特征相匹配的10例健康对照者,对cLBP患者进行2周悬吊训练干预.使用经颅磁刺激技术记录干预前后cLBP患者和健康对照组多裂肌的运动诱发电位,经过数据处理绘制脑部地形...     

Chronic pain in rehabilitation medicine

In this paper the chronicity of pain in non-specific pain syndromes is discussed. Experts in the study of pain with several professional backgrounds in rehabilitation are the authors of this paper. Clinical experience and literature form the basis of the paper. Non-specific low back pain and Complex Regional Pain Syndrome type I (CRPS-I) are discussed in the light of chronic pain. Many definitions of chronic pain exist. Yellow flags are important factors to identify possible chronic pain. In the acute phase of a non-specific pain complaint one should try to identify possible psychosocial inciting risk factors. Behavioural and cognitive treatment seems to be effective for chronic pain patients.     

Patient acceptable symptom state for patient-reported outcomes in people with non-specific chronic low back pain

BackgroundThe patient acceptable symptom state (PASS) is a treatment-response criterion developed to determine the clinical relevance of a treatment effect. Its estimates for some patient-reported outcomes (PROs) in non-specific chronic low back pain (cLBP) are lacking and the stability of PRO estimates between independent cLBP populations is unknown. We hypothesized that these PRO estimates will be stable.ObjectivesTo estimate and compare the PASS for PROs between 2 independent cLBP populations.MethodsWe conducted a secondary analysis of a randomized controlled trial (PREDID) and a cohort of outpatients with non-specific cLBP. Using an anchoring question, participants who self-rated their health as “excellent”, “very good” or “good” at 1 month were considered to have an acceptable symptom state. PASS estimates for 5 PROs were calculated by using the 75th percentile method. Estimates were compared between the 2 populations with bootstrap resampling.ResultsA total of 256 participants with non-specific cLBP were included: 135 patients with cLBP and active discopathy from the PREDID trial and 121 outpatients with cLBP without active discopathy followed up in an independent cohort. Overall, 137/256 (54%) participants had an acceptable symptom state at 1 month. PASS estimates were 47.5 (95% confidence interval [CI] 40.0 to 50.0)/100 for lumbar pain (0, no pain and 100, maximal pain), 30.5 (30.0 to 40.0)/100 for radicular pain, 39.3 (33.6 to 45.3)/100 for Quebec Back Pain Disability score (0, no disability and 100, maximal disability), 10.0 (9.2 to 10.0)/21 for the Hospital Anxiety Depression anxiety subscale (0, no anxiety, and 21, maximal anxiety) and 6.7 (6.0 to 8.0)/21 for the depression subscale (0, no depression, and 21, maximal depression). PASS estimates did not differ between the 2 populations.ConclusionsOur study provides PASS estimates for 5 PROs commonly used in cLBP. Our estimates were stable between 2 independent populations of people with cLBP. The stability of our PASS estimates suggests that they are relevant for interpreting PRO values in clinical trials and practice. ClinicalTrials.gov no. (PREDID trial) NCT00804531.     

Natural course of acute neck and low back pain in the general population: The HUNT study

In this prospective cohort study we aimed to describe the natural course of acute neck and low back pain in a general population of Norway. We screened 9056 subjects aged 20–67 years who participated in a general health survey for a new episode of neck or low back pain the previous month. The screening identified 219 subjects who formed the cohort for this study. Pain intensity was reported on a numeric rating scale (0–10) at 1, 2, 3, 6, and 12 months after start of the new pain episode. The course of pain was described for neck and low back pain, different baseline pain levels, age groups, and number of pain sites at baseline. Use of medication and health care was described and associations between pain intensity and seeking health care were estimated. Pain declined rapidly within 1 month after a new pain episode, with a reduction of 0.91 (95% confidence interval [CI] 0.50–1.32) for neck pain and 1.40 (95% CI 0.82–1.99) for low back pain with little change thereafter. However, pain remained unchanged over the follow-up year for those with equal pain in the neck and low back areas at baseline and for those reporting 4 or more pain sites at baseline. Only 1 in 5 sought health care for their complaints. Still, the course of pain was comparable to effect sizes reported in interventional studies. This study thus contributes natural course reference data for comparisons of pain outcome in clinical trials and practice.     

慢性腰痛患者深层多裂肌EMG信号时频特征变化

目的:采用表面肌电(sEMG)分析系统结合丝电极观察慢性腰痛(cLBP)患者与健康对照者腰部深层多裂肌的肌电活动,比较二者的EMG信号时域和频域特征,探讨腰痛深层多裂肌功能状态变化。方法:选取22例cLBP患者(10男12女)和30例健康对照者(15男15女)采用一次性无菌针头导入不锈钢丝电极(直径0.16mm)至L4水平深层多裂肌后完成改良BST动作,采集多裂肌最大随意收缩时的EMG信号,比较两组平均肌电值(AEMG)、均方根值(RMS)、中位频率(MF)、平均功率频率(MPF)及其频率的特征差异。结果:cLBP腰部深层多裂肌EMG信号时域指标AEMG、RMS明显低于健康对照组(P0.001);频域指标MF、MPF明显高于对照组(P0.05),MFs、MPFs绝对值明显低于对照组(P=0.001/0.001)。结论:最大等长收缩运动中,cLBP患者腰部深层多裂肌电活动异常,可能是持续疼痛刺激引起多裂肌募集能力降低,耐力代偿性增加。     

How to explain central sensitization to patients with 'unexplained' chronic musculoskeletal pain: practice guidelines

Central sensitization provides an evidence-based explanation for many cases of ‘unexplained’ chronic musculoskeletal pain. Prior to commencing rehabilitation in such cases, it is crucial to change maladaptive illness perceptions, to alter maladaptive pain cognitions and to reconceptualise pain. This can be accomplished by patient education about central sensitization and its role in chronic pain, a strategy known as pain physiology education. Pain physiology education is indicated when: 1) the clinical picture is characterized and dominated by central sensitization; and 2) maladaptive illness perceptions are present. Both are prerequisites for commencing pain physiology education. Face-to-face sessions of pain physiology education, in conjunction with written educational material, are effective for changing pain cognitions and improving health status in patients with various chronic musculoskeletal pain disorders. These include patients with chronic low back pain, chronic whiplash, fibromyalgia and chronic fatigue syndrome. After biopsychosocial assessment pain physiology education comprises of a first face-to-face session explaining basic pain physiology and contrasting acute nociception versus chronic pain (Session 1). Written information about pain physiology should be provided as homework in between session 1 and 2. The second session can be used to correct misunderstandings, and to facilitate the transition from knowledge to adaptive pain coping during daily life. Pain physiology education is a continuous process initiated during the educational sessions and continued within both the active treatment and during the longer term rehabilitation program.     

Criteria for inclusion in programs of functional restoration for chronic low back pain: Pragmatic Study

BackgroundIndividuals with chronic low back pain (cLBP) may benefit from multimodal functional restoration programs (FRPs).ObjectiveThe aim of this study was to analyze characteristics of individuals with cLBP who were referred or not to an FRP. Because cLBP is a bio-psycho-social disorder, medical and social parameters were analysed.MethodsThis was an observational cross-sectional study performed in 2017 in 6 tertiary centres in France. Consecutive individuals with cLBP visiting a rheumatologist or physical medicine and rehabilitation physician were included. Individuals referred or not to an FRP were compared by demographic characteristics, duration of sick leave over the past year, self-reported physical activity > 1 h/week, pain (numeric rating scale 0–10), anxiety/depression (Hospital Anxiety and Depression Scale), disability (Oswestry Disability Index) and kinesiophobia (Tampa Kinesiophobia Scale). Univariate and multivariate logistic regression analyses were performed, estimating odds ratios (ORs) and 95% confidence intervals (CIs).ResultsWe included 147 individuals with cLBP. The mean (SD) age was 49 (12) years and 88 (60%) were women; 58 (38%) were referred to an FRP. On multivariate analysis, referral to an FRP was associated with reduced pain level (OR: 0.95, 95% CI: 0.91–0.99, for each 1-point increase in pain score), self-reported lack of physical activity (OR: 0.84, 95% CI: 0.72–0.98) and longer sick leave (OR: 1.03, 95% CI: 1.01–1.05, for 30 more days of sick leave).ConclusionIn this multicentric observational study, referral to an FRP was linked to pain, self-reported physical activity and sick leave but not medical characteristics assessed. These findings confirm the bio-psycho-social approach of FRPs for cLBP.     

Are childhood adversities relevant in patients with chronic low back pain?

Previous studies have found a high number of childhood adversities in patients with chronic low back pain, particularly in patients reporting persisting problems after back surgery. Our aim was to reproduce these results.Within the framework of a comprehensive diagnostic assessment and psychometric evaluation, 109 inpatients who had been treated for low back pain were examined in the orthopedics department of a German university hospital. Five risk factors investigated by Schofferman and his staff (Schofferman et al., 1993) were re-assessed in all of our patients using a structured biographical interview. The German chronic low back pain group was also compared with an age- and gender-matched control group of 109 non-chronic pain patients with respect to these childhood adversities and additional ones.Only approximately 11% of the German chronic low back pain sample demonstrated three or more risk factors, compared with more than 50% in Schofferman's sample, and 47.7% showed none of the five risk factors, compared to only 11% in the Schofferman sample. Moreover, no significant differences in distribution either in terms of the individual risk factors or their cumulative frequency were found in the German chronic low back pain group compared with an age and gender-matched control group without chronic pain.Childhood adversities do not occur frequently in a non-selected group of patients with chronic low back pain. Earlier results showing an increased likelihood of the occurrence of psychosocial risk factors could not be confirmed. As a consequence, further psychic or psychosomatic diagnostics of patients with chronic low back pain are needed to define diagnostic subgroups.     

Research Agenda for the Prevention of Pain and Its Impact: Report of the Work Group on the Prevention of Acute and Chronic Pain of the Federal Pain Research Strategy

After the 2011 Institute of Medicine report on chronic pain, the Interagency Pain Research Coordinating Committee (IPRCC) was created to enhance research efforts among federal agencies. The IPRCC and Office of Pain Policy at the National Institutes of Health collaborated to identify gaps in knowledge and address them via a Federal Pain Research Strategy (FPRS). Interdisciplinary work groups (WGs) were established to make research recommendations in 5 areas: prevention of acute and chronic pain, acute pain and acute pain management, transition from acute to chronic pain, chronic pain and chronic pain management, and disparities in pain and pain care; cross-cutting issues were also considered. The objective was to provide guidance on current research and to make recommendations about addressing identified gaps. Findings from the Prevention of Acute and Chronic Pain WG are summarized in this article. The WG created subgroups to develop recommendations on specific aspects of prevention of acute and chronic pain, including: public education, primary prevention, secondary prevention, tertiary prevention, transition from acute to chronic pain, and cross-cutting mediators. No formal literature review was conducted; however, external advisors were available and consulted as needed. Seven key research priorities were identified. The one deemed “greatest near-term value” was to optimize public health strategies to educate patients on managing pain; that deemed “most impactful” was to determine an association between patient and intervention factors. Other recommendations were related to the epidemiology of acute pain from health care procedures, the epidemiology of acute pain from work-related injuries, safety and effectiveness of management of pain associated with health care procedures, optimizing approaches to acute postsurgical pain, and safety and effectiveness of early interventions for tertiary prevention. Stakeholders, including federally sponsored research programs, researchers, health care providers, policy makers, patients, and others should work together to implement recommendations and address important gaps.

A prognostic approach to defining chronic pain: application to knee pain in older adults

A prognostic approach to defining chronic pain has been proposed as an alternative to traditional definitions based on retrospective duration of pain. While this new approach performs well in low back pain (LBP), headache and orofacial pain, it is not known whether it translates to regional pain syndromes with an underlying pathological component, such as osteoarthritis (OA). We investigated the performance of this approach in a population-based cohort of older adults reporting knee pain, with a spectrum of radiographic knee OA. 676 adults (50 years+) attended a research clinic and were followed up at 18 months and 3 years. Risk scores were calculated using pain intensity, pain duration, pain-related activity, number of pain sites and depressive symptoms, measured at baseline and at 18 months. These scores were used to determine the probability of future clinically significant knee pain, defined as Chronic Pain Grade II-IV, at 18 months and at 3 years using logistic regression. Cut-points on the risk score were applied to determine groups at intermediate (probability >or=0.2), possible (>or=0.5) and probable (>or=0.8) risk of clinically significant knee pain. Discriminative ability of the risk scores, determined by area under the ROC curve, was high (0.78-0.82), varied little by radiographic severity and was superior to pain duration alone. The derived cut-points suggested a lower threshold for each of the risk groups than the previous LBP work. This prognostic approach to defining chronic pain appears to translate well to knee pain. Different cut-points for defining risk groups may be needed for different pain syndromes.     

Relationships between forward head posture and lumbopelvic sagittal alignment in older adults with chronic low back pain

BackgroundAbnormal posture creates abnormal stress and strain in many spinal structures which are considered predisposing factors for chronic mechanical low back pain.PurposeTo examine the relationships among pain intensity, forward head posture (decreased craniovertebral angle) and lumbopelvic sagittal alignment (pelvic incidence, pelvic tilt, sacral slope, and lumbar lordosis) in chronic mechanical low back pain patients.MethodsA cross-section correlational study was conducted on one hundred patients. A numerical-pain-rating scale was used to determine pain intensity. Standardized standing lateral radiographs were analyzed to measure the spinopelvic angles. Reported data were analyzed using correlation coefficients, and regression analyses.ResultsLumbar lordosis had very strong positive correlations with each pain intensity and sacral slope. Pain intensity had a strong positive correlation with sacral slope. Moderate positive correlations highlighted between pelvic tilt and craniovertebral angle. Moreover, the pelvic incidence had weak positive correlations with each sacral slope and pelvic tilt. Negative correlations were strong between pelvic tilt and each of pain intensity, lumbar lordosis and sacral slope. Craniovertebral angle had moderate negative correlations with each of pain, lumbar lordosis, and sacral slope. However, the pelvic incidence had no relations with pain, craniovertebral angle lumbar lordosis. Overall, an association of demographic data and measured variables had a significant effect on the pain multi-regression equation prediction model. They accounted for 76.60% of the variation in pain.ConclusionAbnormal spinopelvic posture relates to chronic mechanical low back pain. There are significant associations among pain intensity, FHP and lumbopelvic sagittal alignment in chronic mechanical low back pain patients.     

An integrated care pathway for the management of low back pain

Low back pain is a disabling condition that is responsible for a considerable amount of health service expenditure [HMSO, London, 1994, p. 1; The Back Pain Revolution. Churchill Livingstone, London, 1999]. Following national recommendations from the Clinical Standards Advisory Group [HMSO, London, 1994, p. 1] and the Royal College of General Practitioner Guidelines [Royal College of General Practice, London, 1996, 1999], local initiatives have attempted to integrate this advice into care pathways for low back pain. This paper will detail the background development, construction and audit of an integrated care pathway for the management of patients with acute low back pain in North Staffordshire.     

Factorial validity of the short-form McGill pain questionnaire (SF-MPQ).

Although widely used, there have been few investigations of the factorial validity of the short-form McGill Pain Questionnaire (SF-MPQ; Melzack, 1987). Confirmatory factor analysis was performed on item responses to the SF-MPQ obtained from 188 patients with chronic back pain. Consistent with the original structure proposed by Melzack (1987), results indicated that the SF-MPQ is best represented by a two-factor solution. However, these findings are contrary to results obtained by Burckhardt and Bjelle (1994) who, using their Swedish version of the SF-MPQ, obtained a three-factor solution. Potential explanations for the disparity between the results of the two studies are explored and recommendations for continuing clinical and research applications are offered.     

Effectiveness of massage therapy for chronic, non-malignant pain: a review

Previous reviews of massage therapy for chronic, non-malignant pain have focused on discrete pain conditions. This article aims to provide a broad overview of the literature on the effectiveness of massage for a variety of chronic, non-malignant pain complaints to identify gaps in the research and to inform future clinical trials. Computerized databases were searched for relevant studies including prior reviews and primary trials of massage therapy for chronic, non-malignant pain. Existing research provides fairly robust support for the analgesic effects of massage for non-specific low back pain, but only moderate support for such effects on shoulder pain and headache pain. There is only modest, preliminary support for massage in the treatment of fibromyalgia, mixed chronic pain conditions, neck pain and carpal tunnel syndrome. Thus, research to date provides varying levels of evidence for the benefits of massage therapy for different chronic pain conditions. Future studies should employ rigorous study designs and include follow-up assessments for additional quantification of the longer-term effects of massage on chronic pain.     

Health care providers' orientations towards common low back pain predict perceived harmfulness of physical activities and recommendations regarding return to normal activity.

The Pain Attitudes and Beliefs Scale for Physiotherapists (PABS-PT) differentiates between a biomedical versus a biopsychosocial treatment orientation with regard to common low back pain. This study re-examined the factor structure and psychometric properties of the PABS-PT, along with the relationship between PABS-PT scores and the perceived harmfulness of physical activities and treatment recommendations for common low back pain. Two hundred and ninety-seven paramedical therapists completed the PABS-PT and questionnaires measuring related concepts, rated the perceived harmfulness of 41 daily physical activities depicted in photographs and gave recommendations for return to normal activity for three patients with low back pain. Analysis revealed two factors labelled 'biomedical' and 'biopsychosocial treatment orientation'. Furthermore, scores on both factors of the PABS-PT were related to measures of related concepts (statistically significant Pearson correlation coefficients between 0.30 and 0.65) such as the HC-PAIRS and a therapist version of the TSK. Regression analyses revealed that both factors were consistent predictors of judgements of the harmfulness of physical activities (PHODA) and of recommendations for return to work and normal activity.     

Are localized low back pain and generalized back pain similar entities? Results of a longitudinal community based study

Purpose. To compare subjects with localized low back pain (LBP) and with generalized back pain (BP) with regard to baseline characteristics and long-term outcomes.

Methods. A community-based longitudinal study. All inhabitants aged 22 - 70 of a single town were asked to complete self-administered questionnaires regarding back and neck pain and lifestyle characteristics. Those reporting LBP during the previous month were followed up after one year. Data were stratified by sites of pain with respect to 'localized LBP' and to 'LBP with additional sites of BP'. Among LBP measures were the Roland and Morris Disability scale and Pain symptoms indices.

Results. Nearly 30% of the total population (602) experienced LBP during the previous month, of whom more than half (336) reported 'localized LBP' and the rest LBP + neck and or upper back pain (Generalized BP). Both subgroups differed from those free of BP, however, those reported 'Generalized BP' comprised more females, were less educated, smoked more, were less engaged in sporting activities and reported higher level of LBP measures than those reported 'localized LBP'. After one year, both subgroups were similar with regard to lifestyle but remained different with regard to some of the LBP measures.

Conclusions. Subjects with 'localized LBP' presented healthier lifestyle than subjects with 'Generalized BP'. The latter experienced higher degree of pain measures. It seems that 'Generalized BP' is not a different entity than 'localized LBP' but rather a more severe one.     

An evidence map of yoga for low back pain

ObjectiveYoga is being increasingly studied as a treatment strategy for a variety of different clinical conditions, including low back pain (LBP). We set out to conduct an evidence map of yoga for the treatment, prevention and recurrence of acute or chronic low back pain (cLBP).MethodsWe searched Medline, Cochrane Database of Systematic Reviews, EMBASE, Allied and Complementary Medicine Database and ClinicalTrials.gov for randomized controlled trials (RCT), systematic reviews or planned studies on the treatment or prevention of acute back pain or cLBP. Two independent reviewers screened papers for inclusion, extracted data and assessed the quality of included studies.ResultsThree eligible systematic reviews were identified that included 10 RCTs (n = 956) that evaluated yoga for non-specific cLBP. We did not identify additional RCTs beyond those included in the systematic reviews. Our search of ClinicalTrials.gov identified one small (n = 10) unpublished trial and one large (n = 320) planned clinical trial. The most recent good quality systematic review indicated significant effects for short- and long-term pain reduction (n = 6 trials; standardized mean difference [SMD] −0.48; 95% CI, −0.65 to −0.31; I² = 0% and n = 5; SMD −0.33; 95% CI, −0.59 to −0.07; I² = 48%, respectively). Long-term effects for back specific disability were also identified (n = 5; SMD −0.35; 95% CI, −0.55 to −0.15; I² = 20%). No studies were identified evaluating yoga for prevention or treatment of acute LBP.ConclusionEvidence suggests benefit of yoga in midlife adults with non-specific cLBP for short- and long-term pain and back-specific disability, but the effects of yoga for health-related quality of life, well- being and acute LBP are uncertain. Without additional studies, further systematic reviews are unlikely to be informative.