Societal beliefs about pain may be more balanced than previously thought. Results of the Guernsey pain survey.

BACKGROUND: Musculoskeletal pain is multidimensional and associated with significant societal impact. Persistent or chronic pain is a public health priority. A step towards high-value care is a contemporary understanding of pain. While pain-related knowledge has been examined in specific conditions (e.g. neck pain) knowledge of the public's broader understanding regarding musculoskeletal pain per se, warrants investigation. This study examined the public's knowledge and beliefs regarding musculoskeletal pain and pain management. METHODS: This observational cohort study was conducted in Guernsey (January 2019-February 2020). Participants (n = 1656; 76.0% female) completed an online questionnaire capturing: demographics, pain experience, work absenteeism, understanding of pain and pain management, multidimensional influences, physical activity, pain catastrophising and healthcare decision-making. Statements were deemed true/false/equivocal and mapped to biopsychosocial/biomedical/neutral perspectives based upon contemporary literature. Descriptive statistics were analysed for each statement. Participants' responses were examined for alignment to a contemporary viewpoint and themes within responses derived using a semi-quantitative approach modelled on direct content analysis. Comparisons between participants with/without pain were examined (χ2-squared/Wilcoxon Rank Sum test). RESULTS: Within the cohort 83.6% reported currently experiencing pain. The overarching theme was perspectives that reflected both biomedical and contemporary, multidimensional understandings of pain. Sub-themes included uncertainty about pain persistence and evidence-based means to reduce recurrence, and reliance upon healthcare professionals for guiding decision-making. Compared to those with pain, those without had a greater belief that psychological interventions may help and lower pain catastrophising. CONCLUSIONS: Participants' understanding of pain demonstrated both biomedical and multidimensional pain understanding consistent with elements of a contemporary understanding of pain.

Interaction analyses: Enhancing understanding of chronic low back pain.

BACKGROUND: Chronic low back pain (CLBP) is complex. Statistical examination of influences of exposures (e.g. characteristics) upon outcomes (e.g. pain) facilitates understanding of complexity and personalized care. Psychological factors may be associated with higher disability following exercise in CLBP. Examining interactions of psychological variables with exercise on disability might further understanding of CLBP. OBJECTIVES: Secondary analysis of data from a CLBP cohort evaluating interactions between psychological variables and exercise on disability. DESIGN: Longitudinal cohort study. METHOD: Variables from a published prognostic model for disability: disability (baseline/one-year follow-up), psychological principal component scores (principal component score two (PC2) - Fear-avoidance beliefs, pain catastrophizing, pain self-efficacy; principal component score three (PC3) - thought suppression, behavioral endurance), exercise (during follow-up), forward-bending time, punishing significant other responses. Differences between exercisers and non-exercisers were assessed using Chi-Squared/Mann-Whitney tests. Multivariable linear regression models for follow-up disability included a term examining interaction between principal component scores and exercise. RESULTS: Exercisers had significantly different scores for PC2 (p = .02) and PC3 (p = .03), lower baseline (p = .005) and follow-up pain intensity (p < .001), follow-up disability (p < .001) and faster forward-bend times (p = .014). There was no significant interaction between exercise and PC2 (p = .92) or PC3 (p = .75). CONCLUSIONS: This study showed no interaction between psychological factors and exercise on disability at follow-up. These findings suggest that the disability outcome of people with CLBP who undertake exercise as an intervention does not differ from those who do not undertake exercise, irrespective of their baseline psychological status.

How do people with chronic low back pain pick a pencil off the floor?

BACKGROUND: Picking objects off the floor is provocative for people with chronic low back pain (CLBP). There are no clinically applicable methods evaluating movement strategies for this task. The relationship between strategy and multidimensional profiles is unknown. OBJECTIVE: Develop a movement evaluation tool (MET) to examine movement strategies in people with CLBP (n = 289) picking a pencil off the floor. Describe those movement strategies, and determine reliability of the MET. Explore differences across multidimensional profiles and movement strategies. METHODS: An MET was developed using literature and iterative processes, and its inter-rater agreement determined. Latent class analysis (LCA) derived classes demonstrating different strategies using six movement parameters as indicator variables. Differences between classes across multidimensional profiles were investigated using analysis of variance, Kruskal-Wallis, or chi-squared tests. RESULTS: Six movement parameters were evaluated. There was substantial inter-rater agreement (Cohen's Kappa = 0.39-0.79) across parameters. LCA derived three classes with different strategies: Class 1 (71.8%) intermediate trunk inclination/knee flexion; Class 2 (24.5%) greater forward trunk inclination, lower knee flexion; Class 3 (3.7%) lower forward trunk inclination, greater knee flexion. Pain duration differed across all classes (p ≤ .001). Time taken to complete forward bends differed between Class 3 and other classes (p = .024). CONCLUSIONS: Movement strategies can be reliably assessed using the MET. Three strategies for picking lightweight objects off the floor were derived, which differed across pain duration and speed of movement.

Effect of Graded Sensorimotor Retraining on Pain Intensity in Patients With Chronic Low Back Pain: A Randomized Clinical Trial.

Importance: The effects of altered neural processing, defined as altering neural networks responsible for perceptions of pain and function, on chronic pain remains unclear. Objective: To estimate the effect of a graded sensorimotor retraining intervention (RESOLVE) on pain intensity in people with chronic low back pain. Design, Setting, and Participants: This parallel, 2-group, randomized clinical trial recruited participants with chronic (>3 months) nonspecific low back pain from primary care and community settings. A total of 276 adults were randomized (in a 1:1 ratio) to the intervention or sham procedure and attention control groups delivered by clinicians at a medical research institute in Sydney, Australia. The first participant was randomized on December 10, 2015, and the last was randomized on July 25, 2019. Follow-up was completed on February 3, 2020. Interventions: Participants randomized to the intervention group (n = 138) were asked to participate in 12 weekly clinical sessions and home training designed to educate them about and assist them with movement and physical activity while experiencing lower back pain. Participants randomized to the control group (n = 138) were asked to participate in 12 weekly clinical sessions and home training that required similar time as the intervention but did not focus on education, movement, and physical activity. The control group included sham laser and shortwave diathermy applied to the back and sham noninvasive brain stimulation. Main Outcomes and Measures: The primary outcome was pain intensity at 18 weeks, measured on an 11-point numerical rating scale (range, 0 [no pain] to 10 [worst pain imaginable]) for which the between-group minimum clinically important difference is 1.0 point. Results: Among 276 randomized patients (mean [SD] age, 46 [14.3] years; 138 [50%] women), 261 (95%) completed follow-up at 18 weeks. The mean pain intensity was 5.6 at baseline and 3.1 at 18 weeks in the intervention group and 5.8 at baseline and 4.0 at 18 weeks in the control group, with an estimated between-group mean difference at 18 weeks of -1.0 point ([95% CI, -1.5 to -0.4]; P = .001), favoring the intervention group. Conclusions and Relevance: In this randomized clinical trial conducted at a single center among patients with chronic low back pain, graded sensorimotor retraining, compared with a sham procedure and attention control, significantly improved pain intensity at 18 weeks. The improvements in pain intensity were small, and further research is needed to understand the generalizability of the findings. Trial Registration: ANZCTR Identifier: ACTRN12615000610538.

Is low intensity exercise sufficient to induce exercise-induced pain threshold modulation in people with persistent pain?

OBJECTIVES: We investigated whether a 12-min walk test (12MWT) yielded exercise-induced pain threshold modulation (EIPM) within people with persistent pain and whether baseline self-report and pain sensitivity measures differed according to these responses. DESIGN: Cross-sectional study. METHODS: Two cohorts (tertiary/community) (n = 88) with persistent pain underwent pressure pain threshold (PPT) testing before and after a 12MWT to determine exercise-induced pain threshold modulation responses. Baseline self-report (pain severity, pain distribution, psychological distress, sleep) and baseline widespread pain sensitivity (WPS) (high/low) were recorded. Within and between-group differences were analysed using paired t-tests and repeated measure analyses of covariance. Individual EIPM responses were categorised as hyperalgesic, no change and hypoalgesic responses. Differences in baseline self-report and pain sensitivity measures between EIPM categories were investigated. RESULTS: No significant within- or between-group differences in PPT following the 12MWT were detected (p > 0.05). Individual responses showed that up to 30% of the community and 44% of the tertiary cohort demonstrated >20% change in PPT (in either direction). Significant differences were shown in pain distribution (p = 0.002) and baseline WPS (p = 0.001) between people with hyperalgesic, no change, hypoalgesic responses. People with 4-5 pain regions were more likely hyperalgesic (χ2 = 9.0, p = 0.003); people with low baseline WPS were more likely to demonstrate no change (p = 0.002). CONCLUSION: Low or self-selected intensity exercise was insufficient to induce exercise-induced pain modulation at group level. Individual responses were variable with pain distribution and baseline WPS differing between responses. Future research could evaluate responses and associated factors in larger samples with high baseline pain sensitivity specifically.

Significant other interactions in people with chronic low back pain: Subgrouping and multidimensional profiles.

Background: Back pain is complex. Social support and significant other interactions influence the pain experience. Purpose: To statistically derive subgroups of people with chronic low back pain based upon their interactions with significant others, and profile subgroups across multidimensional variables. Research Design: Longitudinal cohort study. Study Sample: People with chronic axial low back pain (n = 262). Data Collection and Analysis: Latent class analysis of significant other interaction data was used to derive subgroups of people with chronic low back pain. Subgroups were profiled across baseline multidimensional variables and one-year follow-up pain intensity, disability and bothersomeness. Results: Three clusters were identified: Cluster 1 (7.6%) characterised by the lowest distracting, punishing and solicitous interactions. Cluster 2 (16.0%) characterised by the highest distracting and solicitous responses and social support. Cluster 3 (76.3%) characterised by the highest punishing and lowest social support. Cluster 1 reported less disability than Clusters 2 and 3. Mindfulness was significantly different across all subgroups with Cluster 1 being most mindful and Cluster 3 least mindful. Depression, anxiety and stress were significantly higher in Cluster 3 than Cluster 1. Pain catastrophising was higher for Cluster 2 than Clusters 1 and 3. Cluster 2 had lower pressure pain threshold than Clusters 1 and 3. Conclusions: These results support the association between significant other interactions and the experience of back pain. Considering significant other interactions in clinical practice may be important for managing some people's presentation.

"I Don't Know Why I've Got this Pain!" Allostasis as a Possible Explanatory Model.

Explaining the onset and maintenance of pain can be challenging in many clinical presentations. Allostasis encompasses the mechanisms through which humans adapt to stressors to maintain physiological stability. Due to related neuro-endocrine-immune system effects, allostasis and allostatic load (the cumulative effects on the brain and body that develop through the maintenance of physiological stability) offer the potential to explain the development and maintenance of musculoskeletal pain in certain cases. This paper outlines the concept of allostatic load, highlights the evidence for allostatic load in musculoskeletal pain conditions to date, and discusses mechanisms through which allostatic load influences pain, with particular focus on hypothalamic-pituitary-adrenal axis and sympathetic nervous system function and central, brain-driven governance of these systems. Finally, through case examples, consideration is given as to how allostatic load can be integrated into clinical reasoning and how it can be used to help explain pain to individuals and guide clinical decision-making. IMPACT: Awareness of the concept of allostatic load, and subsequent assessment of physical and psychological stressors potentially contributing to allostatic load, may facilitate a broader understanding of the multidimensional presentations of many people with pain, both acute and persistent. This may facilitate discussion between clinicians and their patients regarding broader influences on their presentations and drive more targeted and inclusive pain management strategies.

Do chronic low back pain subgroups derived from dynamic quantitative sensory testing exhibit differing multidimensional profiles?

OBJECTIVES: The relationship of pain sensitivity with pain and disability in low back pain (LBP) is complicated. It has been suggested increased understanding of dynamic quantitative sensory testing (QST) might be useful in increasing understanding of these relationships. This study aimed to create subgroups based on participant responses to dynamic QST, profile these subgroups based on multidimensional variables (including clinical measures of pain and disability, psychological and lifestyle variables and static QST), and investigate the association of subgroup membership with levels of pain intensity, LBP-related disability and disability risk at 12-month follow up. METHODS: Participants (n=273) with dominant axial chronic non-specific LBP with duration of pain >3 months were included in this study. At baseline, eligible participants completed a self-report questionnaire to collect demographic, clinical, psychological and lifestyle data prior to dynamic and static QST. Dynamic QST measures were conditioned pain modulation (CPM) and temporal summation (TS). At 12-months follow up, clinical data were collected, including pain intensity and LBP-related disability. Sub-groups were formed by cross-tabulation. Analysis was undertaken to profile dynamic QST subgroup on demographic, clinical, psychological, lifestyle and static QST measures. Associations between dynamic QST subgroups and follow-up clinical variables were examined. RESULTS: Based on dynamic QST, participants were allocated into four subgroups; normal CPM and normal TS (n=34, 12.5%); normal CPM and facilitated TS (n=6, 2.2%); impaired CPM and normal TS (n=186, 68.1%); impaired CPM and facilitated TS (n=47, 17.2%). At baseline no differences were demonstrated between subgroups across most clinical variables, or any psychological or lifestyle measures. The two subgroups with impaired CPM were more likely to have a higher number of painful body areas. Cold pain sensitivity was heightened in both the subgroups with facilitated TS. Subgroups did not differ across pain intensity, LBP-related disability and disability risk stratification at follow-up. CONCLUSIONS: The profiles of people with axial LBP did not vary significantly across dynamic QST subgroups, save for those in groups with impaired CPM being more likely to have more widespread symptoms and those with facilitated TS having heightened cold pain sensitivity. Further, subgroup membership was not related to future pain and disability. The role of dynamic QST profiles in LBP remains unclear. Further work is required to understand the role of pain sensitivity in LBP. The utility of dynamic QST subgrouping might not be in determining of future disability. Future research might focus on treatment modifying effects of dynamic QST subgroups.

Masterclass: A pragmatic approach to pain sensitivity in people with musculoskeletal disorders and implications for clinical management for musculoskeletal clinicians.

INTRODUCTION: Research on musculoskeletal disorders indicates that pain sensitivity can be an important consideration for musculoskeletal clinicians in the holistic view of a patient presentation. However, diversity in research findings in this field can make this a difficult concept for clinicians to navigate. Limited integration of the concept of pain sensitivity into clinical practice for musculoskeletal clinicians has been noted. PURPOSE: The purpose of this masterclass is to provide a framework for the consideration of pain sensitivity as a contributing factor in the presentation of people with musculoskeletal pain. It provides pragmatic synthesis of the literature related to pain sensitivity through a lens of how this information can inform clinical practice for musculoskeletal clinicians. Guidance is provided in a 'how to' format for integration of this knowledge into the clinical encounter to facilitate personalised care. IMPLICATIONS: The relationship of pain sensitivity with pain and disability is not clear or linear. The real importance of pain sensitivity in a clinical presentation may be: (1) the potential for pain sensitivity to modify the effect of common treatments utilised by musculoskeletal clinicians, or (2) the effect of pain sensitivity on the prognosis/course of a disorder. Screening tools and subjective features have been highlighted to indicate when physical assessment of pain sensitivity should be prioritised in the physical examination. A pragmatic blueprint for specific assessment related to pain sensitivity has been outlined. A framework for integrating assessment findings into clinical reasoning to formulate management plans for the pain sensitive patient is provided.

Development and preliminary validation of the Chronic Pain Acceptance Questionnaire for Clinicians.

Background and Aims Higher chronic pain acceptance is associated with lower pain and disability. Clinician beliefs are associated with patients' beliefs. This study therefore aimed to develop the Chronic Pain Acceptance Questionnaire for Clinicians (CPAQ-C) to measure clinicians' beliefs regarding the importance of levels of acceptance in patients with chronic pain, and to examine the questionnaire's psychometric properties. Methods Phase one: the CPAQ-C was adapted from the Chronic Pain Acceptance Questionnaire. Data on 162 completed questionnaires were analysed using Rasch analysis. Phase Two: the cohort completed the Healthcare Providers Pain and Impairment Relationship Scale, and the association (Pearson's correlation co-efficient) between these questionnaires examined to assist CPAQ-C validation. Twenty-four participants completed the CPAQ-C one-week later. Test re-test reliability was examined using intraclass correlation co-efficient (2,1) and standard error of measurement. Phase Three: to examine responsiveness 17 clinicians attending a workshop on Acceptance and Commitment Therapy completed the CPAQ-C before and immediately after the workshop, and six-months later. The Skillings Mack test was used to determine whether CPAQ-C scores differed across different timepoints. Results Rasch analysis supported two subscales: activity engagement and pain willingness. Five poorly functioning items were excluded. There was good correlation between the CPAQ-C and Healthcare Providers Pain and Impairment Relationship Scale (-.54). The CPAQ-C demonstrated good reliability (ICC (2,1): .81; standard error of measurement: 4.76). There was significant improvement in CPAQ-C scores following the workshop (p=<.001). Conclusions The CPAQ-C appears a valid, reliable and responsive measure of clinicians' beliefs regarding the importance of levels of acceptance in patients with chronic pain. Implications Where the CPAQ-C reveals that clinicians have low perceived levels of importance regarding acceptance in patients with chronic pain those clinicians may benefit from specific education, however, this requires further examination.

External rotator strength deficits in non-athletic people with rotator cuff related shoulder pain are not associated with pain intensity or disability levels.

BACKGROUND: Strength deficits are often reported in people with rotator cuff related shoulder pain. However, these have mainly been tested in athletic populations and pain interference with testing has not been considered. OBJECTIVES: To examine strength without pain interference in non-athletic people with rotator cuff related shoulder pain and its association with pain intensity and disability. DESIGN: Cross-sectional study. METHODS: Sixty-seven participants with rotator cuff related shoulder pain were assessed for isometric strength of shoulder external rotator and internal rotator muscles without pain interference with a hand-held dynamometer. Strength was normalized (%body weight). Differences in external and internal rotation strength and external:internal rotator strength ratio between symptomatic and asymptomatic sides were examined (Independent t-tests, Wilcoxon rank sum tests). Spearman's rank correlation coefficients were used to examine associations between strength and pain and disability levels. RESULTS: There was no significant difference in internal rotator strength normalized to body weight between symptomatic and asymptomatic sides. There was a significant difference in external rotator strength normalized to body weight (p < .001) and external:internal ratio (p < .001) between sides. No significant correlations were found between strength and pain or disability levels. CONCLUSION: Non-athletic people with rotator cuff related shoulder pain had external rotator strength deficits without pain interference during strength testing, which were not associated with pain and disability levels.

Is rotator cuff related shoulder pain a multidimensional disorder? An exploratory study.

Background and aims Rotator cuff related shoulder pain has been associated with factors from multiple dimensions such as strength changes, psychosocial measures, comorbidities and level of education. However, to date little research has been undertaken to evaluate which factors explain the greatest variance in pain and disability levels in people with rotator cuff related shoulder pain. The objective of this study was therefore to evaluate which multidimensional examination findings were associated with higher pain and disability in a primary care cohort with rotator cuff related shoulder pain. Methods This was an exploratory cross-sectional cohort study. Sixty-seven participants with rotator cuff related shoulder pain were assessed for: pain intensity, disability; demographic, psychological, social and lifestyle characteristics, and isometric strength of shoulder internal and external rotator muscles. Univariable associations between pain intensity/disability and each variable were assessed using linear regression. Variables with univariable associations (p < 0.1) were entered into backwards stepwise multivariable regression models. Results The multivariable model for pain intensity included sleep and perceived persistence and explained 46.5% of the variance (37.6% uniquely by sleep, 5.4% uniquely by perceived persistence). The multivariable model for disability included sleep and sex and explained 26.8% of the variance (4.5% shared by predictors, 16.4% uniquely by sleep, 5.9% uniquely by sex). Conclusions Rotator cuff-related shoulder pain and disability are associated with sleep disturbance, perceived symptom persistence and sex. Rotator cuff related shoulder pain may be considered a multidimensional disorder. Implications Clinicians need to evaluate sleep and perceived symptom persistence in people with rotator cuff related shoulder pain. Future research may examine whether management strategies for RCRSP directed towards these factors afford improved treatment outcomes.

Changing the Narrative in Diagnosis and Management of Pain in the Sacroiliac Joint Area.

The sacroiliac joint (SIJ) is often considered to be involved when people present for care with low back pain where SIJ is located. However, determining why the pain has arisen can be challenging, especially in the absence of a specific cause such as pregnancy, disease, or trauma, when the SIJ might be identified as a source of symptoms with the help of manual clinical tests. Nonspecific SIJ-related pain is commonly suggested to be causally associated with movement problems in the SIJ(s)-a diagnosis traditionally derived from manual assessment of movements of the SIJ complex. Management choices often consist of patient education, manual treatment, and exercise. Although some elements of management are consistent with guidelines, this Perspective article argues that the assumptions on which these diagnoses and treatments are based are problematic, particularly if they reinforce unhelpful, pathoanatomical beliefs. This article reviews the evidence regarding the clinical detection and diagnosis of SIJ movement dysfunction. In particular, it questions the continued use of assessing movement dysfunction despite mounting evidence undermining the biological plausibility and subsequent treatment paradigms based on such diagnoses. Clinicians are encouraged to align their assessment methods and explanatory models with contemporary science to reduce the risk of their diagnoses and choice of intervention negatively affecting clinical outcomes.

Chronic low back pain is highly individualised: patterns of classification across three unidimensional subgrouping analyses.

BACKGROUND AND AIMS: Chronic low back pain (CLBP) is a complex disorder where central and peripheral nociceptive processes are influenced by factors from multiple dimensions associated with CLBP (e.g. movement, pain sensitivity, psychological). To date, outcomes for treatments matched to unidimensional subgroups (e.g. psychologically-based) have been poor. Therefore, unidimensional subgrouping may not reflect the complexity of CLBP presentations at an individual level. The aim of this study was therefore to explore patterns of classification at an individual level across the three previously-published, data-driven, within-dimension subgrouping studies. METHODS: Cross-sectional, multidimensional data was collected in 294 people with CLBP. Statistical derivation of subgroups within each of three clinically-important dimensions (pain sensitivity, psychological profile, pain responses following repeated spinal bending) was briefly reviewed. Patterns of classification membership were subsequently tabulated across the three dimensions. RESULTS: Of 27 possible patterns across these dimensions, 26 were represented across the cohort. CONCLUSIONS: This result highlights that while unidimensional subgrouping has been thought useful to guide treatment, it is unlikely to capture the full complexity of CLBP. The amount of complexity important for best patient outcomes is currently untested. IMPLICATIONS: For clinicians this study highlights the high variability of presentations of people with CLBP at the level of the individual. For example, clinician's should not assume that those with high levels of pain sensitivity will also have high psychological distress and have pain summation following repeated spinal bending. A more flexible, multidimensional, clinically-reasoned approach to profile patient complexity may be required to inform individualised, patient-centred care. Such individualised care might improve treatment efficacy. This study also has implications for researchers; highlighting the inadequacy of unidimensional subgrouping processes and methodological difficulties in deriving subgroups across multidimensional data.

STarT Back Tool risk stratification is associated with changes in movement profile and sensory discrimination in low back pain: A study of 290 patients.

BACKGROUND: Investigation of movement and sensory profiles across STarT Back risk subgroups. METHODS: A chronic low back pain cohort (n = 290) were classified as low, medium or high risk using the STarT Back Tool, and completed a repeated spinal bending task and quantitative sensory testing. Pain summation, time taken and the number of protective behaviours with repeated bending were measured. Sensory tests included two-point discrimination, temporal summation, pressure/thermal pain thresholds and conditioned pain modulation. Subgroups were profiled against movement and sensory variables. RESULTS: The high-risk subgroup demonstrated greater pain summation following repeated forward bending (p < 0.001). The medium-risk subgroup demonstrated greater pain summation following repeated backward bending (p = 0.032). Medium- and high-risk subgroups demonstrated greater forward/backward bend time compared to the low-risk subgroup (p = 0.001, p = 0.005, respectively). Medium- and high-risk subgroups demonstrated a higher number of protective behaviours per forward bend compared to the low-risk subgroup (p = 0.008). For sensory variables, only two-point discrimination differed between subgroups, with medium- and high-risk subgroups demonstrating higher thresholds (p = 0.016). CONCLUSIONS: This study showed altered movement characteristics and sensory discrimination across SBT risk subgroups in people with CLBP. Membership of the high SBT risk subgroup was associated with greater pain and disability levels, greater pain summation following repeated bending, slower bending times, a greater number of protective behaviours during forward bending, and a higher TPD threshold. Treatment outcomes for higher risk SBT subgroups may be enhanced by interventions specifically targeting movement and sensory alterations. SIGNIFICANCE: In 290 people with chronic low back pain movement profile and two-point discrimination threshold differed across risk subgroups defined by the STarT Back Tool. Conversely, pain sensitivity did not differ across these subgroups. These findings may add further guidance for targeted care in these subgroups.

The predictive ability of the STarT Back Tool was limited in people with chronic low back pain: a prospective cohort study.

QUESTIONS: In people with chronic non-specific low back pain (LBP), what is the predictive and discriminative validity of the STarT Back Tool (SBT) for pain intensity, self-reported LBP-related disability, and global self-perceived change at 1-year follow-up? What is the profile of the SBT risk subgroups with respect to demographic variables, pain intensity, self-reported LBP-related disability, and psychological measures? DESIGN: Prospective cohort study. PARTICIPANTS: A total of 290 adults with dominant axial LBP of≥3months' duration recruited from the general community, and private physiotherapy, psychology, and pain-management clinics in Western Australia. OUTCOME MEASURES: The 1-year follow-up measures were pain intensity, LBP-related disability, and global self-perceived change. RESULTS: Outcomes were collected on 264 participants. The SBT categorised 82 participants (28%) as low risk, 116 (40%) as medium risk, and 92 (32%) as high risk. The risk subgroups differed significantly (p<0.05) on baseline pain, disability, and psychological scores. The SBT's predictive ability was strongest for disability: RR was 2.30 (95% CI 1.28 to 4.10) in the medium-risk group and 2.86 (95% CI 1.60 to 5.11) in the high-risk group. The SBT's predictive ability was weaker for pain: RR was 1.25 (95% CI 1.04 to 1.51) in the medium-risk group and 1.26 (95% CI 1.03 to 1.52) in the high-risk group. For the SBT total score, the AUC was 0.71 (95% CI 0.64 to 0.77) for disability and 0.63 (95% CI 0.55 to 0.71) for pain. CONCLUSION: This was the first large study to investigate the SBT in a population exclusively with chronic LBP. The SBT provided an acceptable indication of 1-year disability, had poor predictive and discriminative ability for future pain, and was unable to predict or discriminate global perceived change. In this cohort with chronic non-specific LBP, the SBT's predictive and discriminative abilities were restricted to disability at 1year. [Kendell M, Beales D, O'Sullivan P, Rabey M, Hill J, Smith A (2018) The predictive ability of the STarT Back Tool was limited in people with chronic low back pain: a prospective cohort study. Journal of Physiotherapy 64: 107-113].

Multidimensional Prognostic Modelling in People With Chronic Axial Low Back Pain.

OBJECTIVES: To derive prognostic models for people with chronic low back pain (CLBP) (n=294) based upon an extensive array of potentially prognostic multidimensional factors. MATERIALS AND METHODS: This study entered multidimensional data (demographics, pain characteristics, pain responses to movement, behaviors associated with pain, pain sensitivity, psychological, social, health, lifestyle) at baseline, and interventions undertaken, into prognostic models for pain intensity, disability, global rating of change and bothersomeness at 1-year. RESULTS: The prognostic model for higher pain intensity (explaining 23.2% of the variance) included higher baseline pain intensity and punishing spousal interactions, and lower years in education, while participating in exercise was prognostic of lower pain intensity. The model for higher disability (33.6% of the variance) included higher baseline disability, longer forward bending time, psychological principal component scores representing negative pain-related cognitions and punishing spousal interactions; while exercising was prognostic of lower disability. The odds of reporting global rating of change much/very much improved were increased by participating in exercise, having leg pain as well as CLBP and having greater chronic pain acceptance. The receiver operating characteristic area under the curve was 0.72 indicating acceptable discrimination. The odds of reporting very/extremely bothersome CLBP were increased by having higher baseline pain intensity, longer forward bending time and receiving injection(s); while higher age, more years in education and having leg pain decreased the odds (receiver operating characteristic area under the curve, 0.80; acceptable discrimination). DISCUSSION: The variance explained by prognostic models was similar to previous reports, despite an extensive array of multidimensional baseline variables. This highlights the inherent multidimensional complexity of CLBP.