Identifying potential moderators for response to treatment in low back pain: A systematic review

Treatment Effect Modifiers for Return-to-Work in Patients With Musculoskeletal Disorders

Investigating how individual characteristics modify treatment effects can improve understanding, interpretation, and translation of trial findings. The purpose of this secondary analysis was to identify treatment effect modifiers of the MI-NAV trial, a 3 arm, parallel randomized controlled trial which compared motivational interviewing and stratified vocational advice intervention in addition to usual case management (UC), to UC alone. This study included (n = 514) participants with musculoskeletal disorders on sick leave for at least 50% of their contracted work hours for at least 7 consecutive weeks with the Norwegian Labour and Welfare Administration. Sickness absence days was the primary outcome, measured from baseline assessment date until the 6-month follow-up. Potential treatment effect modifiers, identified a priori and informed by expert consultation and literature, were evaluated using linear regression models and statistical interaction tests. For motivational interviewing versus UC, age (mean difference [MD] -.7, 95% confidence interval [CI] -1.5 to .2; P = .13) and self-perceived health status (MD -.3, 95% CI -.7 to .1; P = .19) were identified as potential effect modifiers (P ≤ .2). For stratified vocational advice intervention versus UC, analgesic medication use (MD -26.2, 95% CI -45.7 to -6.7; P = .009) was identified as a treatment effect modifier (P ≤ .05). These findings may assist in more targeted treatment adaptation and translation as well as the planning of future clinical trials. PERSPECTIVE: This secondary analysis of the MI-NAV trial found that analgesic medication use, age, and self-perceived health may modify the effect of 2 vocational interventions on reducing sickness absence in people with musculoskeletal disorders.

EMDR v. other psychological therapies for PTSD: a systematic review and individual participant data meta-analysis

BACKGROUND

This systematic review and individual participant data meta-analysis (IPDMA) examined the overall effectiveness of eye movement desensitization and reprocessing (EMDR) in reducing posttraumatic stress disorder (PTSD) symptoms, achieving response and remission, and reducing treatment dropout among adults with PTSD compared to other psychological treatments. Additionally, we examined available participant-level moderators of the efficacy of EMDR.

METHODS

This study included randomized controlled trials. Eligible studies were identified by a systematic search in PubMed, Embase, PsyclNFO, PTSDpubs, and CENTRAL. The target population was adults with above-threshold baseline PTSD symptoms. Trials were eligible if at least 70% of study participants had been diagnosed with PTSD using a structured clinical interview. Primary outcomes included PTSD symptom severity, treatment response, and PTSD remission. Treatment dropout was a secondary outcome. The systematic search retrieved 15 eligible randomized controlled trials (RCTs); 8 of these 15 were able to be included in this IPDMA (346 patients). Comparator treatments included relaxation therapy, emotional freedom technique, trauma-focused cognitive behavioral psychotherapies, and REM-desensitization.

RESULTS

One-stage IPDMA found no significant difference between EMDR and other psychological treatments in reducing PTSD symptom severity (β = -0.24), achieving response (β = 0.86), attaining remission (β = 1.05), or reducing treatment dropout rates (β = -0.25). Moderator analyses found unemployed participants receiving EMDR had higher PTSD symptom severity at the post-test, and males were more likely to drop out of EMDR treatment than females.

CONCLUSION

The current study found no significant difference between EMDR and other psychological treatments. We found some indication of the moderating effects of gender and employment status.

Machine learning-based identification of determinants for rehabilitation success and future healthcare use prevention in patients with high-grade, chronic, nonspecific low back pain: an individual data 7-year follow-up analysis on 154,167 individuals

ABSTRACT

To individually prescribe rehabilitation contents, it is of importance to know and quantify factors for rehabilitation success and the risk for a future healthcare use. The objective of our multivariable prediction model was to determine factors of rehabilitation success and the risk for a future healthcare use in patients with high-grade, chronic low back pain. We included members of the German pension fund who participated from 2012 to 2019 in multimodal medical rehabilitation with physical and psychological treatment strategies because of low back pain (ICD10:M54.5). Candidate prognostic factors for rehabilitation success and for a future healthcare use were identified using Gradient Boosting Machines and Random Forest algorithms in the R-package caret on a 70% training and a 30% test set. We analysed data from 154,167 patients; 8015 with a second medical rehabilitation measure and 5161 who retired because of low back pain within the study period. The root-mean-square errors ranged between 494 (recurrent rehabilitation) and 523 (retirement) days ( R2 = 0.183-0.229), whereas the prediction accuracy ranged between 81.9% for the prediction of the rehabilitation outcome, and 94.8% for the future healthcare use prediction model. Many modifiable prognostic factors (such as duration of the rehabilitation [inverted u-shaped], type of the rehabilitation, and aftercare measure), nonmodifiable prognostic factors (such as sex and age), and disease-specific factors (such as sick leave days before the rehabilitation [linear positive] together with the pain grades) for rehabilitation success were identified. Inpatient medical rehabilitation programmes (3 weeks) may be more effective in preventing a second rehabilitation measure and/or early retirement because of low back pain compared with outpatient rehabilitation programs. Subsequent implementation of additional exercise programmes, cognitive behavioural aftercare treatment, and following scheduled aftercare are likely to be beneficial.

Covariate Adjustment in Chronic Pain Trials: An Oft-Missed Opportunity

Self-reported pain intensity, frequently used as an outcome in randomized clinical trials (RCTs) of chronic pain, is often highly variable and could be associated with multiple baseline factors. Thus, the assay sensitivity of pain trials (ie, the ability of the trial to detect a true treatment effect) could be improved by including prespecified baseline factors in the primary statistical model. The objective of this focus article was to characterize the baseline factors included in statistical analyses of chronic pain RCTs. Seventy-three RCTs published between 2016 and 2021 that investigated interventions for chronic pain were included. The majority of trials identified a single primary analysis (72.6%; n = 53). Of these, 60.4% (n = 32) included one or more covariates in the primary statistical model, most commonly baseline value of the primary outcome, study site, sex, and age. Only one of the trials reported information regarding associations between covariates and outcomes (ie, information that could inform prioritization of covariates for prespecification in future analyses). These findings demonstrate inconsistent use of covariates in the statistical models in chronic pain clinical trials. Prespecified adjustments for baseline covariates that could increase precision and assay sensitivity should be considered in future clinical trials of chronic pain treatments. PERSPECTIVE: This review demonstrates inconsistent inclusion and potential underutilization of covariate adjustment in analyses of chronic pain RCTs. This article highlights areas for possible improvement in design and reporting related to covariate adjustment to improve efficiency in future RCTs.

Quantifying the association between psychological distress and low back pain in urban Europe: a secondary analysis of a large cross-sectional study

OBJECTIVES

This study aims to estimate the prevalence of low back pain (LBP) in Europe and to quantify its associated mental and physical health burdens among adults in European urban areas.

DESIGN

This research is a secondary analysis of data from a large multicountry population survey.

SETTING

The population survey on which this analysis is based was conducted in 32 European urban areas across 11 countries.

PARTICIPANTS

The dataset for this study was collected during the European Urban Health Indicators System 2 survey. There were a total of 19 441 adult respondents but data from 18 028, 50.2% female (9 050) and 49.8% male (8 978), were included in these analyses.

PRIMARY AND SECONDARY OUTCOME MEASURES

Being a survey, data on the exposure (LBP) and outcomes were collected simultaneously. The primary outcomes for this study are psychological distress and poor physical health.

RESULTS

The overall European prevalence of LBP was 44.6% (43.9-45.3) widely ranging from 33.4% in Norway to 67.7% in Lithuania. After accounting for sex, age, socioeconomic status and formal education, adults in urban Europe suffering LBP had higher odds of psychological distress aOR 1.44 (1.32-1.58) and poor self-rated health aOR 3.54 (3.31-3.80). These associations varied widely between participating countries and cities.

CONCLUSION

Prevalence of LBP, and its associations with poor physical and mental health, varies across European urban areas.

Treatment effect modifiers for individuals with acute low back pain: secondary analysis of the TARGET trial

ABSTRACT

Treatment effect modifiers identify patient characteristics associated with treatment responses. The purpose of this secondary analysis was to identify potential treatment effect modifiers for disability from the TARGET trial that compared usual care (control) with usual care + psychologically informed physical therapy (PIPT). The sample consisted of a STarT Back tool identified high-risk patients with acute low back pain that completed Oswestry Disability Index (ODI) data at index visit and 6 months later (n = 1250). Candidate treatment effect modifiers were identified a priori and informed by the literature. Linear mixed models tested for treatment effect modification through tests of statistical interaction. All statistical interactions ( P ≤ 0.20) were stratified by modifier to inspect for specific effects ( P ≤ 0.05). Smoking was identified as a potential effect modifier (treatment * smoking interaction, P = 0.08). In participants who were smokers, the effect of PIPT was (ODI = 5.5; 95% CI: 0.6-10.4; P = 0.03) compared with usual care. In participants who were nonsmokers, the effect of PIPT was (ODI = 1.5; 95% CI: -1.4 to 4.4; P = 0.31) compared with usual care. Pain medication was also identified as a potential effect modifier (treatment × pain medication interaction, P = 0.10). In participants prescribed ≥3 pain medications, the effect of PIPT was (ODI = 7.1; 95% CI: -0.1 to 14.2; P = 0.05) compared with usual care. The PIPT effect for participants prescribed no pain medication was (ODI = 3.5; 95% CI: -0.4 to 7.4; P = 0.08) and for participants prescribed 1 to 2 pain medications was (ODI = 0.6; 95% CI: -2.5 to 3.7; P = 0.70) when compared with usual care. These findings may be used for generating hypotheses and planning future clinical trials investigating the effectiveness of tailored application of PIPT.

The Area Deprivation Index Corresponds Effectively With Other Measures of Objective Socioeconomic Status in Adults With Chronic Low Back Pain

Background and Purpose: How the Area Deprivation Index (ADI) performs compared to other measures of socioeconomic status (SES) is unknown. The study purpose is to compare the ADI and other measures of SES in their ability to predict pain severity/interference. Methods: Four measures of SES were compared-ADI, income, education, and subjective social status (SSS). Results: Pain severity/interference correlated positively with ADI (r = .396/r = .33), and negatively with income (r = -.507/r = -.428) and education (r = -.271/r = -.102). Criterion scores of the pain severity model suggest income performs best (AIC = 428.29/BIC = 436.22), followed by ADI (AIC = 437.24/BIC = 445.17), with education performing least well (AIC = 446.35/BIC = 454.29). Similar results were seen for the pain interference model. Conclusions: Neighborhood-level factors warrant consideration along with individual-level factors when attempting to understand the impact of SES on chronic low back pain.

Characteristics of office workers who benefit most from interventions for preventing neck and low back pain: a moderation analysis

Number of working hours, work-related psychological demands, and use of lumbar support moderate the beneficial effects of preventive interventions for neck and low back pain.

Introduction:

Neck and low back pain are significant health problem in sedentary office workers. Active break and postural shift interventions has been proved to reduce the incidence of new onset of both neck and low back pain.

Objectives:

To identify variables that moderate the effects of active breaks and postural shift interventions on the development of neck and low back pain in office workers.

Methods:

Using data from a 3-arm (active break, postural shift, and control group) cluster randomized controlled trial (N = 193), we evaluated the moderating effects of age, job position, education level, sex, perceived psychological work demands, number of working hours, and using a chair with lumbar support on the benefits of 2 interventions designed to prevent the development of neck and low back pain in office workers. Moderation analyses were conducted using the Hayes PROCESS macro, with post hoc Johnson–Neyman techniques and logistic regressions.

Results:

Significant interactions between intervention groups and 3 moderators assessed at baseline emerged. For the prevention of neck pain, the effect of the active break intervention was moderated by the number of working hours and the effect of the postural shift intervention was moderated by the level of perceived psychological work demands and the number of working hours. For the prevention of low back pain, the effect of postural shift intervention was moderated by having or not having a chair with lumbar support.

Conclusions:

The study findings can be used to help determine who might benefit the most from 2 treatments that can reduce the risk of developing neck and low back pain in sedentary workers and may also help us to understand the mechanisms underlying the benefits of these interventions.

The association between patients' illness perceptions and longitudinal clinical outcome in patients with low back pain

Initial perceptions regarding prognosis and treatment effects were prominent perceptions explaining longitudinal outcomes in patients with low back pain, including explaining patients' development of self-management strategies.

Introduction:

Illness perception is suggested to influence outcome in patients with low back pain (LBP). It is unknown if specific illness perceptions are of more importance for longitudinal outcomes, including development of self-management strategies.

Objectives:

This study explores whether patients' initial illness perceptions were associated with disability, pain, health-related quality of life, and self-care enablement outcomes in patients with LBP after 3 and 12 months.

Methods:

Four hundred sixty-seven consecutive patients seeking physiotherapeutic primary care for LBP were eligible to participate in this prospective cohort study, providing data at baseline and after 3 and 12 months (mean age 45 years, 56% women). Multiple linear regression analysis was used to explore whether patients' illness perceptions at baseline were associated with outcome in the Oswestry Disability Index (ODI), Numeric Rating Scale–LBP (NRS-LBP), EuroQol Five Dimensions, and Patient Enablement Instrument (PEI).

Results:

Stronger beliefs that the back problem will last a long time at baseline were associated with worse outcome in ODI, NRS-LBP, and PEI at 3 and 12 months and in EuroQol Five Dimensions at 12 months. Negative beliefs regarding treatment's ability to improve LBP were associated with worse outcome in NRS-LBP and PEI at 3 and 12 months and in ODI at 12 months.

Conclusions:

Illness perceptions regarding prognosis and treatment's ability to improve symptoms were the most prominent perceptions explaining several longitudinal clinical outcomes. These expectations should be addressed in an early stage in the delivery of interventions for LBP. These expectations were also important for patients' development of coping and self-management strategies.

Do recommended interventions widen or narrow inequalities in musculoskeletal health? An equity-focussed systematic review of differential effectiveness

Background

It is unclear whether seven interventions recommended by Public Health England for preventing and managing common musculoskeletal conditions reduce or widen health inequalities in adults with musculoskeletal conditions.

Methods

We used citation searches of Web of Science (date of ‘parent publication’ for each intervention to April 2021) to identify original research articles reporting subgroup or moderator analyses of intervention effects by social stratifiers defined using the PROGRESS-Plus frameworks. Randomized controlled trials, controlled before-after studies, interrupted time series, systematic reviews presenting subgroup/stratified analyses or meta-regressions, individual participant data meta-analyses and modelling studies were eligible. Two reviewers independently assessed the credibility of effect moderation claims using Instrument to assess the Credibility of Effect Moderation Analyses. A narrative approach to synthesis was used (PROSPERO registration number: CRD42019140018).

Results

Of 1480 potentially relevant studies, seven eligible analyses of single trials and five meta-analyses were included. Among these, we found eight claims of potential differential effectiveness according to social characteristics, but none that were judged to have high credibility.

Conclusions

In the absence of highly credible evidence of differential effectiveness in different social groups, and given ongoing national implementation, equity concerns may be best served by investing in monitoring and action aimed at ensuring fair access to these interventions.

[Noninvasive Treatments for Acute and Chronic Back Pain]

Noninvasive Treatments for Acute and Chronic Back Pain Abstract. The therapy of back pain - especially the medication with opioids - can be challenging for the treating physician. Specific back pain can often be diagnosed by imaging and successfully treated by surgery or medication. In contrast, nonspecific back pain can be worsened by inappropriate imaging, questionable surgical indications and uncontrolled drug use. For the therapy of nonspecific back pain, maintaining daily activity and exercise therapy is central. Opioids are effective drugs for short-term use. However, long-term use often leads to opioid-induced hyperalgesia and hormonal dysfunction with decreased quality of life and libido. Furthermore, opioids can lead to abuse and addiction. After an ineffective treatment with non-opioids, opioids may be given for a limited time period (if possible shorter than four weeks) according to international guidelines.

Effectiveness of motor control exercise on non-specific chronic low back pain, disability and core muscle morphological characteristics: A meta-analysis of randomized controlled trials

INTRODUCTION

Chronic low back pain (CLBP) has been recognized as the leading cause of disability. Up to 90% of patients with CLBP are classified as having non-specific CLBP (NSCLBP). Motor control exercise (MCE) is one of the most popular and widespread treatment options, and has many advantages in alleviating pain and disability. This meta-analysis is aimed to investigate the effectiveness of MCE on NSCLBP, disability, and core muscles reported in randomized controlled trials (RCTs).

METHODS

PubMed, Web of Science, and EMBASE were searched from inception to August 2020. Articles were eligible if they were RCTs that evaluated MCE against sham or other treatments in isolation and measured outcomes including pain intensity and disability or core muscles morphologic characteristics.

RESULTS

Two authors independently extracted the data. Eighteen studies of 897 studies with a total of 1333 individuals with NSCLBP were retained for the meta-analysis. Compared with other conservative treatments, MCE was better in reducing pain and disability posttreatment and was better in reducing pain at the 6-month follow-up period. However, it had comparable effects on pain reduction at 12-month and 24-month follow-up period, and on disability at the 6-month, 12-month and 24-month follow-up period. MCE resulted in comparable effects to other treatments in improving the core muscle thickness posttreatment. However, other important outcomes, such as the function, strength and endurance of core muscles, which could hamper a comprehensive understanding of the effects of MCE on NSCLBP.

LIMITATIONS

Publication bias was not assessed in several comparisons due to the scarcity of data in published literature. This might downgrade the strength of the evidence. The protocol of this meta-analysis was reviewed by an expert committee, but was not registered in a public trial registry.

CONCLUSIONS

Low to very low quality of evidence supported that MCE resulted in a greater reduction of pain and disability posttreatment, and a greater reduction of pain at the 6-month follow-up than other treatments for NSCBLP. The findings in this review further support that MCE may be more effective than other treatments at short-term followups, and at least has equivalent long-term effects to other forms of treatments in NSCLBP.

Moderators of the Effect of Spinal Manipulative Therapy on Pain Relief and Function in Patients with Chronic Low Back Pain: An Individual Participant Data Meta-analysis

STUDY DESIGN

Individual participant data (IPD) meta-analysis.

OBJECTIVE

The aim of this study was to identify which participant characteristics moderate the effect of spinal manipulative therapy (SMT) on pain and functioning in chronic LBP.

SUMMARY OF BACKGROUND

The effects of SMT are comparable to other interventions recommended in guidelines for chronic low back pain (LBP); however, it is unclear which patients are more likely to benefit from SMT compared to other therapies.

METHODS

IPD were requested from randomized controlled trials (RCTs) examining the effect of SMT in adults with chronic LBP for pain and function compared to various other therapies (stratified by comparison). Potential patient moderators (n = 23) were a priori based on their clinical relevance. We investigated each moderator using a one-stage approach with IPD and investigated this interaction with the intervention for each time point (1, 3, 6, and 12 months).

RESULTS

We received IPD from 21 of 46 RCTs (n = 4223). The majority (12 RCTs, n = 2249) compared SMT to recommended interventions. The duration of LBP, baseline pain (confirmatory), smoking, and previous exposure to SMT (exploratory) had a small moderating effect across outcomes and follow-up points; these estimates did not represent minimally relevant differences in effects; for example, patients with <1 year of LBP demonstrated more positive point estimates for SMT versus recommended therapy for the outcome pain (mean differences ranged from 4.97 (95% confidence interval, CI: -3.20 to 13.13) at 3 months, 10.76 (95% CI: 1.06 to 20.47) at 6 months to 5.26 (95% CI: -2.92 to 13.44) at 12 months in patients with over a year LBP. No other moderators demonstrated a consistent pattern across time and outcomes. Few moderator analyses were conducted for the other comparisons because of too few data.

CONCLUSION

We did not identify any moderators that enable clinicians to identify which patients are likely to benefit more from SMT compared to other treatments.Level of Evidence: 2.

What Mediates Treatment Effects in a Presurgery Physiotherapy Treatment in Surgical Candidates With Degenerative Lumbar Spine Disorders? A Mediation and Conditional Process Analysis of the PREPARE Randomized Controlled Trial

OBJECTIVES

Treatment guidelines recommend targeting both physical and psychological factors in interventions for degenerative lumbar spine disorders. Studying the treatment mechanisms gives information on key factors explaining the outcome improvement that can refine treatments. This study explores treatment mediators in a physiotherapy treatment on disability, pain intensity, and health-related quality of life in surgical candidates with degenerative lumbar spine disorders compared with waiting-list controls. An additional aim was to evaluate patients' expectation as a moderator of treatment outcome.

MATERIALS AND METHODS

Data collected from 197 patients in a single-blinded randomized controlled trial comparing 9 weeks of multifaceted physiotherapy with waiting-list controls were used in this conditional process analysis. Analysis was carried out on group differences for change in Oswestry Disability Index, Pain Visual Analog Scale (VAS) back pain, EuroQol-5D, and EuroQol-VAS. The putative moderation role of expectations and mediation role of change in physical variables and psychosocial variables were tested.

RESULTS

Change in self-efficacy mediated improvement in all outcomes. Improvement in Oswestry Disability Index was also mediated by change in depression; VAS was mediated by change in fear-avoidance beliefs; and EuroQol-VAS was mediated by change in activity level and fear avoidance beliefs. Improvements were moderated by patients' treatment expectations.

DISCUSSION

Self-efficacy, fear-avoidance beliefs, physical activity level, and patients' treatment expectations were found to be important factors explaining treatment effects. Self-efficacy was the consistent mediator for effects of the presurgical physiotherapy on disability, back pain intensity, and health-related quality of life.

Identification of subgroup effect with an individual participant data meta-analysis of randomised controlled trials of three different types of therapist-delivered care in low back pain

Background

Proven treatments for low back pain, at best, only provide modest overall benefits. Matching people to treatments that are likely to be most effective for them may improve clinical outcomes and makes better use of health care resources.

Methods

We conducted an individual participant data meta-analysis of randomised controlled trials of three types of therapist delivered interventions for low back pain (active physical, passive physical and psychological treatments). We applied two statistical methods (recursive partitioning and adaptive risk group refinement) to identify potential subgroups who might gain greater benefits from different treatments from our individual participant data meta-analysis.

Results

We pooled data from 19 randomised controlled trials, totalling 9328 participants. There were 5349 (57%) females with similar ratios of females in control and intervention arms. The average age was 49 years (standard deviation, SD, 14).

Participants with greater psychological distress and physical disability gained most benefit in improving on the mental component scale (MCS) of SF-12/36 from passive physical treatment than non-active usual care (treatment effects, 4.3; 95% confidence interval, CI, 3.39 to 5.15). Recursive partitioning method found that participants with worse disability at baseline gained most benefit in improving the disability (Roland Morris Disability Questionnaire) outcome from psychological treatment than non-active usual care (treatment effects, 1.7; 95% CI, 1.1 to 2.31). Adaptive risk group refinement did not find any subgroup that would gain much treatment effect between psychological and non-active usual care. Neither statistical method identified any subgroups who would gain an additional benefit from active physical treatment compared to non-active usual care.

Conclusions

Our methodological approaches worked well and may have applicability in other clinical areas. Passive physical treatments were most likely to help people who were younger with higher levels of disability and low levels of psychological distress. Psychological treatments were more likely to help those with severe disability. Despite this, the clinical importance of identifying these subgroups is limited. The sizes of sub-groups more likely to benefit and the additional effect sizes observed are small. Our analyses provide no evidence to support the use of sub-grouping for people with low back pain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04028-8.

Effect of comorbid migraine on propranolol efficacy for painful TMD in a randomized controlled trial

Introduction

The migraine-preventive drug propranolol is efficacious in reducing pain from temporomandibular disorder, suggesting potential modifying or mediating effects of comorbid migraine.

Methods

In this randomized controlled trial, myofascial temporomandibular disorder patients were treated with propranolol or placebo for 9 weeks. The primary endpoint was change in a facial pain index derived from daily symptom diaries. Linear and logistic regression models tested for a migraine × treatment-group interaction in reducing facial pain index. Counterfactual models explored changes in headache impact and heart rate as mediators of propranolol's efficacy.

Results

Propranolol's efficacy in reducing facial pain index was greater among the 104 migraineurs than the 95 non-migraineurs: For example, for the binary ≥ 30% reduction in facial pain index, odds ratios were 3.3 (95% confidence limits: 1.4, 8.1) versus 1.3 (0.5, 3.2), respectively, although the interaction was statistically non-significant (p = 0.139). Cumulative response curves confirmed greater efficacy for migraineurs than non-migraineurs (differences in area under the curve 26% and 6%, respectively; p = 0.081). While 9% of the treatment effect was mediated by reduced headache impact, 46% was mediated by reduced heart rate.

Conclusions

Propranolol was more efficacious in reducing temporomandibular disorder pain among migraineurs than non-migraineurs, with more of the effect mediated by reduced heart rate than by reduced headache impact.

Study identification and registration

SOPPRANO; NCT02437383; https://clinicaltrials.gov/ct2/show/NCT02437383

Which Chronic Low Back Pain Patients Respond Favorably to Yoga, Physical Therapy, and a Self-care Book? Responder Analyses from a Randomized Controlled Trial

PURPOSE

To identify baseline characteristics of adults with chronic low back pain (cLBP) that predict response (i.e., a clinically important improvement) and/or modify treatment effect across three nonpharmacologic interventions.

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Academic safety net hospital and seven federally qualified community health centers.

SUBJECTS

Adults with cLBP (N = 299).

METHODS

We report patient characteristics that were predictors of response and/or modified treatment effect across three 12-week treatments: yoga, physical therapy [PT], and a self-care book. Using preselected characteristics, we used logistic regression to identify predictors of "response," defined as a ≥30% improvement in the Roland Morris Disability Questionnaire. Then, using "response" as our outcome, we identified baseline characteristics that were treatment effect modifiers by testing for statistical interaction (P < 0.05) across two comparisons: 1) yoga-or-PT vs self-care and 2) yoga vs PT.

RESULTS

Overall, 39% (116/299) of participants were responders, with more responders in the yoga-or-PT group (42%) than the self-care (23%) group. There was no difference in proportion responding to yoga (48%) vs PT (37%, odds ratio [OR] = 1.5, 95% confidence interval = 0.88 - 2.6). Predictors of response included having more than a high school education, a higher income, employment, few depressive symptoms, lower perceived stress, few work-related fear avoidance beliefs, high pain self-efficacy, and being a nonsmoker. Effect modifiers included use of pain medication and fear avoidance beliefs related to physical activity (both P = 0.02 for interaction). When comparing yoga or PT with self-care, a greater proportion were responders among those using pain meds (OR = 5.3), which differed from those not taking pain meds (OR = 0.94) at baseline. We also found greater treatment response among those with lower (OR = 7.0), but not high (OR = 1.3), fear avoidance beliefs around physical activity.

CONCLUSIONS

Our findings revealed important subgroups for whom referral to yoga or PT may improve cLBP outcomes.

Age differences in cognitive-affective processes in adults with chronic pain

BACKGROUND

Chronic pain is associated with significant physical and psychological impairments across the adult lifespan. However, there is a relative gap in knowledge on individual differences that predict pain-related functioning. The current study highlights one important source of individual variation: age.

METHODS

We used cross-sectional data from a large treatment-seeking cohort of 2,905 adults (M age = 46.6 [13.1]; 71.8% women) presenting to a tertiary pain centre in the United Kingdom to determine age differences in cognitive-affective processes (catastrophizing, acceptance, self-efficacy), including their differential patterns and effects on disability and depression.

RESULTS

Older adults (ages 65-75) were found to experience higher pain acceptance and pain self-efficacy compared to both middle-aged (ages 40-64) and young adult (ages 18-39) age groups. Older adults also experienced lower levels of catasophizing compared to middle-age adults. Testing age as a moderator, we found that the relationships of pain self-efficacy and acceptance with depression as well as the relationship between pain self-efficacy and disability were comparatively weakest among older adults and strongest among young adults. Similarly, the relationship between pain catastrophizing and depression was relatively stronger for young and middle-aged adults compared to older adults.

CONCLUSIONS

Age-related differences in psychological mechanisms that influence pain-related functioning present unique challenges and opportunities for scientists and clinicians to improve our understanding and treatment of pain across the lifespan. Additional work is needed to refine our knowledge of age-related differences in cognitive-affective, biopsychosocial dimensions of chronic pain and to develop and test the efficacy of age-tailored interventions.

SIGNIFICANCE

Our cross-sectional analysis of 2,905 treatment-seeking adults with chronic pain presenting to a tertiary care center in the United Kingdom revealed distinct age differences in cognitive-affective linked to disability and depression. This study contributes to the limited knowledge on age-related variance in psychological mechanisms underlying adjustment to chronic pain. Promising avenues for future research include refining our understanding of age-related differences in cognitive-affective, biopsychosocial dimensions of chronic pain and elucidating the most salient treatment targets among different age groups.

Psychosocial Moderators and Mediators of Sensorimotor Exercise in Low Back Pain: A Randomized Multicenter Controlled Trial

The effects of exercise interventions on unspecific chronic low back pain (CLBP) have been investigated in many studies, but the results are inconclusive regarding exercise types, efficiency, and sustainability. This may be because the influence of psychosocial factors on exercise induced adaptation regarding CLBP is neglected. Therefore, this study assessed psychosocial characteristics, which moderate and mediate the effects of sensorimotor exercise on LBP. A single-blind 3-arm multicenter randomized controlled trial was conducted for 12-weeks. Three exercise groups, sensorimotor exercise (SMT), sensorimotor and behavioral training (SMT-BT), and regular routines (CG) were randomly assigned to 662 volunteers. Primary outcomes (pain intensity and disability) and psychosocial characteristics were assessed at baseline (M1) and follow-up (3/6/12/24 weeks, M2-M5). Multiple regression models were used to analyze whether psychosocial characteristics are moderators of the relationship between exercise and pain, meaning that psychosocial factors and exercise interact. Causal mediation analysis were conducted to analyze, whether psychosocial characteristics mediate the exercise effect on pain. A total of 453 participants with intermittent pain (mean age = 39.5 ± 12.2 years, f = 62%) completed the training. It was shown, that depressive symptomatology (at M4, M5), vital exhaustion (at M4), and perceived social support (at M5) are significant moderators of the relationship between exercise and the reduction of pain intensity. Further depressive mood (at M4), social-satisfaction (at M4), and anxiety (at M5 SMT) significantly moderate the exercise effect on pain disability. The amount of moderation was of clinical relevance. In contrast, there were no psychosocial variables which mediated exercise effects on pain. In conclusion it was shown, that psychosocial variables can be moderators in the relationship between sensorimotor exercise induced adaptation on CLBP which may explain conflicting results in the past regarding the merit of exercise interventions in CLBP. Results suggest further an early identification of psychosocial risk factors by diagnostic tools, which may essential support the planning of personalized exercise therapy. Level of Evidence: Level I. Clinical Trial Registration: DRKS00004977, LOE: I, MiSpEx: grant-number: 080102A/11-14. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00004977.

Improving Veteran Access to Integrated Management of Back Pain (AIM-Back): Protocol for an Embedded Pragmatic Cluster-Randomized Trial

BACKGROUND

Coordinated efforts between the National Institutes of Health, the Department of Defense, and the Department of Veterans Affairs have built the capacity for large-scale clinical research investigating the effectiveness of nonpharmacologic pain treatments. This is an encouraging development; however, what constitutes best practice for nonpharmacologic management of low back pain (LBP) is largely unknown.

DESIGN

The Improving Veteran Access to Integrated Management of Back Pain (AIM-Back) trial is an embedded pragmatic cluster-randomized trial that will examine the effectiveness of two different care pathways for LBP. Sixteen primary care clinics will be randomized 1:1 to receive training in delivery of 1) an integrated sequenced-care pathway or 2) a coordinated pain navigator pathway. Primary outcomes are pain interference and physical function (Patient-Reported Outcomes Measurement Information System Short Form [PROMIS-SF]) collected in the electronic health record at 3 months (n=1,680). A subset of veteran participants (n=848) have consented to complete additional surveys at baseline and at 3, 6, and 12 months for supplementary pain and other measures.

SUMMARY

AIM-Back care pathways will be tested for effectiveness, and treatment heterogeneity will be investigated to identify which veterans may respond best to a given pathway. Health care utilization patterns (including opioid use) will also be compared between care pathways. Therefore, the AIM-Back trial will provide important information that can inform the future delivery of nonpharmacologic treatment of LBP.

Tourniquet use for knee replacement surgery

BACKGROUND

Many surgeons prefer to perform total knee replacement surgery with the aid of a tourniquet. A tourniquet is an occlusive device that restricts distal blood flow to help create a bloodless field during the procedure. A tourniquet may be associated with increased risk of pain and complications.

OBJECTIVES

To determine the benefits and harms of tourniquet use in knee replacement surgery.

SEARCH METHODS

We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) up to 26 March 2020. We searched clinicaltrials.gov, the World Health Organization trials portal, and several international registries and joint registries up to March 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing knee replacement with use of a tourniquet versus without use of a tourniquet and non-randomised studies with more than 1000 participants. Major outcomes included pain, function, global assessment of success, health-related quality of life, serious adverse events (including venous thromboembolism, infection, re-operation, and mortality), cognitive function, and survival of the implant. Minor outcomes included blood loss, economic outcomes, implant stability, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors screened abstracts and full texts, extracted data, performed risk of bias assessments, and assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 41 RCTs with 2819 participants. Trials included from 20 to 199 participants. Mean age ranged between 58 and 84 years. More than half of the RCTs had unclear risk of selection bias and unclear risk of performance and detection bias due to absence of blinding of participants and surgeons. Major outcomes Pain: at postoperative day 1, pain (on a scale from zero to 10, with higher scores indicating worse pain) was ranked at 4.56 points after surgery without a tourniquet and at 1.25 points (MD) higher (95% CI 0.32 higher to 2.19 higher) with a tourniquet (8 studies; 577 participants), for an absolute difference of 12.5% higher pain scores (95% CI 3.2% higher to 21.9% higher) and a relative difference of 19% higher pain scores (95% CI 3.4% higher to 49% higher) with a tourniquet. Evidence for these findings was of moderate certainty, downgraded due to risk of bias. Knee replacement with a tourniquet probably led to higher postoperative pain scores at day 1, although this difference may or may not be noticeable to patients (based on a minimal clinically important difference (MCID) of 1.0). Function: at 12 months, tourniquet use probably makes little or no difference to function, based on an MCID of 5.3 for Knee Society Score (KSS) and 5.0 for Oxford Knee Score (OKS). Mean function (on a scale from 0 to 100, with higher scores indicating better outcomes) was 90.03 points after surgery without a tourniquet and was 0.29 points worse (95% CI 1.06 worse to 0.48 better) on a 0 to 100 scale, absolute difference was 0.29% worse (1.06% worse to 0.48% better), with a tourniquet (5 studies; 611 participants). This evidence was downgraded to moderate certainty due to risk of bias. Global assessment of success: low-certainty evidence (downgraded due to bias and imprecision) indicates that tourniquet use may have little or no effect on success. At six months, 47 of 50 (or 940 per 1000) reported overall successful treatment after surgery without a tourniquet and 47 of 50 (or 940 per 1000) with a tourniquet (risk ratio (RR) 1.0, 95% CI 0.91 to 1.10) based on one study with 100 participants. Health-related quality of life: at six months, tourniquet may have little or no effect on quality of life. The 12-Item Short Form Survey (SF-12) score (mental component from zero to 100 (100 is best)) was 54.64 after surgery without a tourniquet and 1.53 (MD) better (95% CI 0.85 worse to 3.91 better) with a tourniquet (1 study; 199 participants); absolute difference was 1.53% better (0.85% worse to 3.91% better). Evidence was of low certainty, downgraded due to risk of bias and small number of participants. Serious adverse events: the risk of serious adverse events was probably higher with tourniquet; 26 of 898 (29 per 1000) reported events following surgery without a tourniquet compared to 53 of 901 (59 per 1000) with a tourniquet (RR 1.73, 95% CI 1.10 to 2.73) in 21 studies (1799 participants). Twenty-nine more per 1000 patients (95% CI 3 to 50 more per 1000 patients) had a serious adverse event with a tourniquet. Forty-eight (95% CI 20 to 345) participants would need to have surgery without a tourniquet to avoid one serious adverse event. This evidence was downgraded to moderate certainty due to risk of bias. Cognitive function: one study reported cognitive function as an outcome; however the data were incompletely reported and could not be extracted for analysis. Survival of implant: it is uncertain if tourniquet has an effect on implant survival due to very low certainty evidence (downgraded for bias, and twice due to very low event rates); 2 of 107 (19 per 1000) required revision surgery in the surgery with a tourniquet group compared to 1 of 107 (9 per 1000) without a tourniquet group at up to two years' follow-up (RR 1.44, 95% CI 0.23 to 8.92). This equates to a 0.4% (0.7% lower to 7% more) increased absolute risk in surgery with a tourniquet.

AUTHORS' CONCLUSIONS

Moderate certainty evidence shows that knee replacement surgery with a tourniquet is probably associated with an increased risk of serious adverse events. Surgery with a tourniquet is also probably associated with higher postoperative pain, although this difference may or may not be noticeable to patients. Surgery with a tourniquet does not appear to confer any clinically meaningful benefit on function, treatment success or quality of life. Further research is required to explore the effects of tourniquet use on cognitive function and implant survival, to identify any additional harms or benefits. If a tourniquet continues to be used in knee replacement surgery, patients should be informed about the potential increased risk of serious adverse events and postoperative pain.

A multisite longitudinal evaluation of patient characteristics associated with a poor response to non-surgical multidisciplinary management of low back pain in an advanced practice physiotherapist-led tertiary service

BACKGROUND

Non-surgical multidisciplinary management is often the first pathway of care for patients with chronic low back pain (LBP). This study explores if patient characteristics recorded at the initial service examination have an association with a poor response to this pathway of care in an advanced practice physiotherapist-led tertiary service.

METHODS

Two hundred and forty nine patients undergoing non-surgical multidisciplinary management for their LBP across 8 tertiary public hospitals in Queensland, Australia participated in this prospective longitudinal study. Generalised linear models (logistic family) examined the relationship between patient characteristics and a poor response at 6 months follow-up using a Global Rating of Change measure.

RESULTS

Overall 79 of the 178 (44%) patients completing the Global Rating of Change measure (28.5% loss to follow-up) reported a poor outcome. Patient characteristics retained in the final model associated with a poor response included lower Formal Education Level (ie did not complete school) (Odds Ratio (OR (95% confidence interval)) (2.67 (1.17-6.09), p = 0.02) and higher self-reported back disability (measured with the Oswestry Disability Index) (OR 1.33 (1.01-1.77) per 10/100 point score increase, p = 0.046).

CONCLUSIONS

A low level of formal education and high level of self-reported back disability may be associated with a poor response to non-surgical multidisciplinary management of LBP in tertiary care. Patients with these characteristics may need greater assistance with regard to their comprehension of health information, and judicious monitoring of their response to facilitate timely alternative care if no benefits are attained.

A tool to improve functional outcome assessment of a multimodal program for patients with chronic low back pain: A study on walk tests (at comfortable and fast speed)

BACKGROUND

Tools for functional assessment of chronic low back pain (LBP) are lacking.

OBJECTIVE

To determine the correlations and the responsiveness of the 400 m comfortable walk test (400 mCWT) and the 200 m fast-walk test (200 mFWT) in the functional assessment of a multimodal program.

METHODS

One hundred and twenty-seven participants (68 females) with LBP and with or without radicular pain completed a Quebec Back Pain Disability Scale, a Sorensen test, a Shirado test, a 400 mCWT and a 200 mFWT, at baseline and at the end of the program.

RESULTS

No significant side effect was reported during walk tests. Walking speed was significantly increased after the program (0.18 ± 0.15 m.s-1 for the 400 mCWT and 0.17 ± 0.17 m.s-1 for the 200 mFWT). Clinical parameters were also significantly improved (82.02 ± 83.1 seconds for the Shirado, 92.1 ± 100.1 seconds for the Sorensen, -14.0 ± 12.9 for the Quebec scale). A significant relationship was found between the increase in walking speed for the two walk tests and the improvement of the Quebec scale. The gait speed improvement was close to the minimal clinically important change (95% confidence interval: 0.14-0.22) determined from the Quebec scale threshold (minimum detectable change).

CONCLUSIONS

Both 400 mCWT and 200 mFWT are correlated with functional parameters and are responsive for the functional assessment of LBP.

Brief Acceptance and Commitment Therapy for Fibromyalgia: Feasibility and Effectiveness of a Replicated Single-Case Design

Objective

Overall, the literature on the effectiveness of psychological treatments in general and those for fibromyalgia in particular has been dominated by research designs that focus on large groups and explore changes on average, so the treatment impact at the individual level remains unclear. In this quasi-experimental, replicated single-case design, we will test the feasibility and effectiveness of a brief acceptance and committed therapy intervention using ecological momentary assessment supported by technology.

Methods

The sample comprised 7 patients (3 in the individual condition and 4 in the group condition) who received a brief, 5-week psychological treatment. Patient evolution was assessed one week prior to treatment onset and during the whole study with a smartphone app. Because ecological momentary assessment and the use of an app are not frequent practices in routine care, we also evaluated the feasibility of this assessment methodology (i.e., compliance with the app). Change was investigated with a nonoverlap of all pairs index. Outcomes were pain interference with sleep and social activities, fatigue, sadness, and pain intensity.

Results

Patient change was not uniform across outcomes. Four patients (two in each condition) showed relatively moderate levels of change (approximately 60% nonoverlap in several outcomes). The remaining patients showed more modest improvements which affected a reduced number of outcomes. Based on nonoverlapping indices, there was no clear evidence in favor of any treatment format.

Conclusions

An alternative design to large-scale trials, one that focuses on the individual change, exists and it can be implemented in pain research. The use of technology (e.g., smartphones) simplifies such designs by facilitating ecological momentary assessment. Based on our findings showing that changes were not homogeneous across patients or outcomes, more single-case designs and patient-centered analyses (e.g., responder and moderation analyses) are required.

Psychological interventions for chronic non-specific low back pain: protocol of a systematic review with network meta-analysis

INTRODUCTION

Psychological factors such as fear avoidance beliefs, depression, anxiety, catastrophic thinking and familial and social stress, have been associated with high disability levels in people with chronic low back pain (LBP). Guidelines endorse the integration of psychological interventions in the management of chronic LBP. However, uncertainty surrounds the comparative effectiveness of different psychological approaches. Network meta-analysis (NMA) allows comparison and ranking of numerous competing interventions for a given outcome of interest. Therefore, we will perform a systematic review with a NMA to determine which type of psychological intervention is most effective for adults with chronic non-specific LBP.

METHODS AND ANALYSIS

We will search electronic databases (MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, Web of Science, SCOPUS and CINAHL) from inception until 22 August 2019 for randomised controlled trials comparing psychological interventions to any comparison interventions in adults with chronic non-specific LBP. There will be no restriction on language. The primary outcomes will include physical function and pain intensity, and secondary outcomes will include health-related quality of life, fear avoidance, intervention compliance and safety. Risk of bias will be assessed using the Revised Cochrane risk-of-bias tool for randomised trials (RoB 2) tool and confidence in the evidence will be assessed using the Confidence in NMA (CINeMA) framework. We will conduct a random-effects NMA using a frequentist approach to estimate relative effects for all comparisons between treatments and rank treatments according to the mean rank and surface under the cumulative ranking curve values. All analyses will be performed in Stata.

ETHICS AND DISSEMINATION

No ethical approval is required. The research will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019138074.

Is intrinsic lumbar spine shape associated with lumbar disc degeneration? An exploratory study

Background

Lumbar disc degeneration (LDD) is a condition associated with recurrent low back pain (LBP). Knowledge regarding effective management is limited. As a step towards the identification of risk, prognostic or potentially modifiable factors in LDD patients, the aim of this study was to explore the hypothesis that intrinsic lumbar spine shape is associated with LDD and clinical outcomes in symptomatic adults.

Methods

3 T MRI was used to acquire T2-weighted sagittal images (L1-S1) from 70 healthy controls and LDD patients (mean age 49 years, SD 11, range 31–71 years). Statistical Shape Modelling (SSM) was used to describe lumbar spine shape. SSM identified variations in lumbar shape as ‘modes’ of variation and quantified deviation from the mean. Intrinsic shape differences were determined between LDD groups using analysis of variance with post-hoc comparisons. The relationship between intrinsic shape and self-reported function, mental health and quality of life were also examined.

Results

The first 7 modes of variation explained 91% of variance in lumbar shape. Higher LDD sum scores correlated with a larger lumbar lordosis (Mode 1 (55% variance), P = 0.02), even lumbar curve distribution (Mode 2 (12% variance), P = 0.05), larger anterior-posterior (A-P) vertebral diameter (Mode 3 (10% variance), P = 0.007) and smaller L4-S1 disc spaces (Mode 7 (2% variance), P ≤ 0.001). In the presence of recurrent LBP, LDD was associated with a larger A-P vertebral diameter (Mode 3) and a more even lumbar curvature with smaller L5/S1 disc spaces (Mode 4), which was significantly associated with patient quality of life (P = 0.002–0.04, r_p = 0.43–0.61)).

Conclusions

This exploratory study provides new evidence that intrinsic shape phenotypes are associated with LDD and quality of life in patients. Longitudinal studies are required to establish the potential role of these risk or prognostic shape phenotypes.

Efficacy and acceptability of pharmacological and non-pharmacological interventions for non-specific chronic low back pain: a protocol for a systematic review and network meta-analysis

BACKGROUND

Despite the enormous financial and humanistic burden of chronic low back pain (CLBP), there is little consensus on what constitutes the best treatment options from a multitude of competing interventions. The objective of this network meta-analysis (NMA) is to determine the relative efficacy and acceptability of primary care treatments for non-specific CLBP, with the overarching aim of providing a comprehensive evidence base for informing treatment decisions.

METHODS

We will perform a systematic search to identify randomised controlled trials of interventions endorsed in primary care guidelines for the treatment of non-specific CLBP in adults. Information sources searched will include major bibliographic databases (MEDLINE, Embase, CENTRAL, CINAHL, PsycINFO and LILACS) and clinical trial registries. Our primary outcomes will be patient-reported pain ratings and treatment acceptability (all-cause discontinuation), and secondary outcomes will be functional ability, quality of life and patient/physician ratings of overall improvement. A hierarchical Bayesian class-based NMA will be performed to determine the relative effects of different classes of pharmacological (NSAIDs, opioids, paracetamol, anti-depressants, muscle relaxants) and non-pharmacological (exercise, patient education, manual therapies, psychological therapy, multidisciplinary approaches, massage, acupuncture, mindfulness) interventions and individual treatments within a class (e.g. NSAIDs: diclofenac, ibuprofen, naproxen). We will conduct risk of bias assessments and threshold analysis to assess the robustness of the findings to potential bias. We will compute the effect of different interventions relative to placebo/no treatment for both short- and long-term efficacy and acceptability.

DISCUSSION

While many factors are important in selecting an appropriate intervention for an individual patient, evidence for the analgesic effects and acceptability of a treatment are key factors in guiding this selection. Thus, this NMA will provide an important source of evidence to inform treatment decisions and future clinical guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registry number: CRD42019138115.

Family History Influences the Effectiveness of Home Exercise in Older People With Chronic Low Back Pain: A Secondary Analysis of a Randomized Controlled Trial

OBJECTIVE

To investigate whether a family history of low back pain (LBP) influences patient outcomes and treatment effects following home exercises in older people with chronic LBP.

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Local community.

PARTICIPANTS

People older than 55 years with chronic LBP (N=60).

INTERVENTIONS

Participants in the intervention group completed video game exercises for 60 minutes 3 times per week for 8 weeks. Participants in the control group were instructed to maintain their usual levels of activity and care seeking behaviors.

MAIN OUTCOMES MEASURES

Participants indicated whether any of their immediate family members had a history of "any" LBP or "activity-limiting" LBP at baseline. We collected self-reported measures of pain, function, pain self-efficacy, care seeking, physical activity, disability, fear of movement and/or reinjury, and falls efficacy at baseline, 8 weeks, 3 months, and 6 months. We performed regression analyses to determine whether a family history of LBP predicted patient outcomes and moderated the effects of home exercise.

RESULTS

Participants with a family history of any LBP were less likely to be highly active than those without a family history (odds ratio, 0.08; 95% CI, 0.01-0.42; P=.003). Home-based video game exercises led to improvements in function in those without a family history of activity-limiting LBP (β=1.78; 95% CI, 0.56-3.00; P=.006) but not in those with a family history (β=-0.17; 95% CI, -2.56 to 2.21; P=.880) (interaction P=.049). A family history of LBP did not influence the remaining patient outcomes or treatment effects.

CONCLUSIONS

A family history of LBP appears to negatively influence physical activity levels in older people with chronic LBP. Further, home-based video game exercises appear to be beneficial for older people with chronic LBP that do not have a family history of LBP.

Potential treatment effect modifiers for manipulative therapy for children complaining of spinal pain.Secondary analyses of a randomised controlled trial

Background

In children, spinal pain is transitory for most, but up to 20% experience recurrent and bothersome complaints. It is generally acknowledged that interventions may be more effective for subgroups of those affected with low back pain. In this secondary analysis of data from a randomized clinical trial, we tested whether five indicators of a potential increased need for treatment might act as effect modifiers for manipulative therapy in the treatment of spinal pain in children. We hypothesized that the most severely affected children would benefit more from manipulative therapy.

Method

This study was a secondary analysis of data from a randomised controlled trial comparing advice, exercises and soft tissue treatment with and without the addition of manipulative therapy in 238 Danish school children aged 9-15 years complaining of spinal pain. A text message system (SMS) and clinical examinations were used for data collection (February 2012 to April 2014).Five pre-specified potential effect modifiers were explored: Number of weeks with spinal pain 6 months prior to inclusion, number of weeks with co-occurring musculoskeletal pain 6 months prior to inclusion, expectations of the clinical course, pain intensity, and quality of life.Outcomes were number of recurrences of spinal pain, number of weeks with pain, length of episodes, global perceived effect, and change in pain intensity. To explore potential effect modification, various types of regression models were used depending on the type of outcome, including interaction tests.

Results

We found that children with long duration of spinal pain or co-occurring musculoskeletal pain prior to inclusion as well as low quality of life at baseline tended to benefit from manipulative therapy over non-manipulative therapy, whereas the opposite was seen for children reporting high intensity of pain. However, most results were statistically insignificant.

Conclusions

This secondary analysis indicates that children more effected by certain baseline characteristics, but not pain intensity, have a greater chance to benefit from treatment that include manipulative therapy. However, these analyses were both secondary and underpowered, and therefore merely exploratory. The results underline the need for a careful choice of inclusion criteria in future investigations of manipulative therapy in children.

Trial registration

NCT01504698; results.

Factors associated with persistently high-cost health care utilization for musculoskeletal pain

BACKGROUND

Musculoskeletal pain conditions incur high costs and produce significant personal and public health consequences, including disability and opioid-related mortality. Persistence of high-cost health care utilization for musculoskeletal pain may help identify system inefficiencies that could limit value of care. The objective of this study was to identify factors associated with persistent high-cost utilization among individuals seeking health care for musculoskeletal pain.

METHODS

This was a retrospective cohort study of Medical Expenditure Panel Survey data (2008-2013) that included a non-institutionalized, population-based sample of individuals seeking health care for a musculoskeletal pain condition (n = 12,985). Expenditures associated with musculoskeletal pain conditions over two consecutive years were analyzed from prescribed medicine, office-based medical provider visits, outpatient department visits, emergency room visits, inpatient hospital stays, and home health visits. Persistent high-cost utilization was defined as being in the top 15th percentile for annual musculoskeletal pain-related expenditures over 2 consecutive years. We used multinomial regression to determine which modifiable and non-modifiable sociodemographic, health, and pain-related variables were associated with persistent high-cost utilization.

RESULTS

Approximately 35% of direct costs for musculoskeletal pain were concentrated among the 4% defined as persistent high-cost utilizers. Non-modifiable variables associated with expenditure group classification included age, race, poverty level, geographic region, insurance status, diagnosis type and total number of musculoskeletal pain diagnoses. Modifiable variables associated with increased risk of high expenditure classification were higher number of missed work days, greater pain interference, and higher use of prescription medication for pain, while higher self-reported physical and mental health were associated with lower risk of high expenditure classification.

CONCLUSIONS

Health care delivery models that prospectively identify these potentially modifiable factors may improve the costs and value of care for individuals with musculoskeletal pain prone to risk for high-cost care episodes.

Associations between psychological symptoms and treatment outcomes of a massage therapy intervention: Secondary analyses of a randomized controlled trial

Massage therapy (MT) may be more effective for certain subgroups of advanced cancer patients, but this is not well-studied. Psychological symptoms are one potential moderator of MT outcomes, as they occur frequently in MT patients. Therefore, we conducted a secondary analysis of data from a multi-site study which compared MT to simple touch in 380 adults with advanced cancer. We examined whether the presence of depression or baseline psychological symptom frequency moderated outcomes of change in pain, interference of pain, quality of life, 60-second heart and respiratory rates, and physical distress. We found significant main effects of depression and baseline psychological symptom frequency on changes in pain, 60-second heart and respiratory rates, quality of life, and physical distress for both MT and simple touch, but did not find differential responses between groups in moderator analyses. Results imply that psychological interventions could be targeted to patients with cancer who are receiving any type of touch therapy to improve outcomes.

The Evolving Case Supporting Individualised Physiotherapy for Low Back Pain

Low-back pain (LBP) is one of the most burdensome health problems in the world. Guidelines recommend simple treatments such as advice that may result in suboptimal outcomes, particularly when applied to people with complex biopsychosocial barriers to recovery. Individualised physiotherapy has the potential of being more effective for people with LBP; however, there is limited evidence supporting this approach. A series of studies supporting the mechanisms underpinning and effectiveness of the Specific Treatment of Problems of the Spine (STOPS) approach to individualised physiotherapy have been published. The clinical and research implications of these findings are presented and discussed. Treatment based on the STOPS approach should also be considered as an approach to individualised physiotherapy in people with LBP.

Acceptance and commitment therapy for chronic pain: protocol of a systematic review and individual participant data meta-analysis

BACKGROUND

Acceptance and commitment therapy (ACT) can be effective in treating chronic pain. Despite evidence supporting the effectiveness of ACT, uncertainties remain regarding which subgroups in the chronic pain population are likely to benefit most and least. This protocol describes the application for two meta-analytic approaches, one at the level of individual participant data and the other at the level of aggregated data, from randomized controlled trials of ACT for chronic pain (ACT-CP-MA).

METHODS

We will systematically conduct literature searches in CENTRAL, MEDLINE, EMBASE, PsycINFO, and trial registers. Two reviewers will independently select studies for inclusion and data extraction. ACT-CP-MA will include randomized controlled trials with ACT for chronic pain compared to control conditions for adults (≥ 18 years) with chronic pain (> 3 months). We will invite the authors of all eligible trials to share individual participant data. Outcomes will include standardized measures of pain interference, pain intensity, depression, anxiety, health-related quality of life, participants' rating of overall improvement, and ACT-related process variables. Using the Cochrane Collaboration's tool and GRADE, reviewers will independently check for risk of bias, quality of evidence, and strength of recommendations. In the individual participant data meta-analysis, we will use a one-step approach where participants are clustered with studies and data from all studies are modeled simultaneously. For analyses, we will use mixed-effects models. Additionally, we will employ a meta-analysis with aggregate data and compare the results of both meta-analyses.

DISCUSSION

This collaborative meta-analysis of individual participant data from randomized controlled trials of ACT for chronic pain versus control conditions will demonstrate how the known benefits of ACT for chronic pain vary across different subtypes of the chronic pain population. The results of the meta-analyses will be based on a comprehensive search of multiple databases and will help to inform future clinical trials and decision-making on the use of ACT in chronic pain and improve the quality, design, and reporting of future trials in this field.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019120901.

Advancing Psychologically Informed Practice for Patients With Persistent Musculoskeletal Pain: Promise, Pitfalls, and Solutions

There has been growing interest in psychologically oriented pain management over the past 3 to 4 decades, including a 2011 description of psychologically informed practice (PIP) for low back pain. PIP requires a broader focus than traditional biomechanical and pathology-based approaches that have been traditionally used to manage musculoskeletal pain. A major focus of PIP is addressing the behavioral aspects of pain (ie, peoples' responses to pain) by identifying individual expectations, beliefs, and feelings as prognostic factors for clinical and occupational outcomes indicating progression to chronicity. Since 2011, the interest in PIP seems to be growing, as evidenced by its use in large trials, inclusion in scientific conferences, increasing evidence base, and expansion to other musculoskeletal pain conditions. Primary care physicians and physical therapists have delivered PIP as part of a stratified care approach involving screening and targeting of treatment for people at high risk for continued pain-associated disability. Furthermore, PIP is consistent with recent national priorities emphasizing nonpharmacological pain management options. In this perspective, PIP techniques that range in complexity are described, considerations for implementation in clinical practice are offered, and future directions that will advance the understanding of PIP are outlined.

Serious Gaming to Support Exercise Therapy for Patients with Chronic Nonspecific Low Back Pain: A Feasibility Study

OBJECTIVE

To investigate the feasibility of a functional exercise program supported by serious gaming for patients with chronic nonspecific low back pain (LBP).

METHODS

Ten patients with chronic nonspecific LBP and an underlying motor control impairment were recruited. Subjects performed a partially supervised exercise program (36 sessions, 18 weeks) that included 30 minutes of general conditioning and 90 minutes of individually tailored functional motor control exercises (MCEs). Serious games (SGs) were used to (1) improve thoracolumbar dissociation and (2) to provide postural feedback during functional MCEs. The SGs were also available at home.

RESULTS

Treatment satisfaction and the scores on the credibility/expectancy questionnaire were good and did not change throughout the intervention. Patients remained motivated throughout the rehabilitation program and no serious adverse events were reported. Overall, participants indicated that the SGs helped them to perform the home exercises more correctly, and as a consequence, they felt more confident doing them. However, the time needed to set up the games was a barrier for home use and participants would have found it useful to receive postural feedback during daily life activities.

CONCLUSIONS

It is feasible to support a functional exercise program with SGs for patients with chronic nonspecific LBP, both in a supervised and a home environment. Time-efficiency and the integration of SGs in daily life activities are challenges that need to be addressed in the future.

Physiotherapists' views of implementing a stratified treatment approach for patients with low back pain in Germany: a qualitative study

Background

The STarT-Back-Approach (STarT: Subgroups for Targeted Treatment) was developed in the UK and has demonstrated clinical and cost effectiveness. Based on the results of a brief questionnaire, patients with low back pain are stratified into three treatment groups. Since the organisation of physiotherapy differs between Germany and the UK, the aim of this study is to explore German physiotherapists’ views and perceptions about implementing the STarT-Back-Approach.

Methods

Three two-hour think-tank workshops with physiotherapists were conducted. Focus groups, using a semi-structured interview guideline, followed a presentation of the STarT-Back-Approach, with discussions audio recorded, transcribed and qualitatively analysed using content analysis.

Results

Nineteen physiotherapists participated (15 female, mean age 41.2 (SD 8.6) years). Three main themes emerged, each with multiple subthemes: 1) the intervention (15 subthemes), 2) the healthcare context (26 subthemes) and 3) individual characteristics (8 subthemes). Therapists’ perceptions of the extent to which the STarT-Back intervention would require changes to their normal clinical practice varied considerably. They felt that within their current healthcare context, there were significant financial disincentives that would discourage German physiotherapists from providing the STarT-Back treatment pathways, such as the early discharge of low-risk patients with supported self-management materials. They also discussed the need for appropriate standardised graduate and post-graduate skills training for German physiotherapists to treat high-risk patients with a combined physical and psychological approach (e.g., communication skills).

Conclusions

Whilst many German physiotherapists are positive about the STarT-Back-Approach, there are a number of substantial barriers to implementing the matched treatment pathways in Germany. These include financial disincentives within the healthcare system to early discharge of low-risk patients. Therapists also highlighted the need for solutions in respect of scalable physiotherapy training to gain skills in combined physical and psychological approaches.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-2991-3) contains supplementary material, which is available to authorized users.

Who Benefits Most From Individualized Physiotherapy or Advice for Low Back Disorders? A Preplanned Effect Modifier Analysis of a Randomized Controlled Trial

STUDY DESIGN

A preplanned effect modifier analysis of the Specific Treatment of Problems of the Spine randomized controlled trial.

OBJECTIVE

To identify characteristics associated with larger or smaller treatment effects in people with low back disorders undergoing either individualized physical therapy or guideline-based advice.

SUMMARY OF BACKGROUND DATA

Identifying subgroups of people who attain a larger or smaller benefit from particular treatments has been identified as a high research priority for low back disorders.

METHODS

The trial involved 300 participants with low back pain and/or referred leg pain (≥6 wk, ≤6 mo duration), who satisfied criteria to be classified into five subgroups (with 228 participants classified into three subgroups relating to disc-related disorders, and 64 classified into the zygapophyseal joint dysfunction subgroup). Participants were randomly allocated to receive either two sessions of guideline based advice (n = 144), or 10 sessions of individualized physical therapy targeting pathoanatomical, psychosocial, and neurophysiological factors (n = 156). Univariate and multivariate linear mixed models determined the interaction between treatment group and potential effect modifiers (defined a priori) for the primary outcomes of back pain, leg pain (0-10 Numeric Rating Scale) and activity limitation (Oswestry Disability Index) over a 52-week follow-up.

RESULTS

Participants with higher levels of back pain, higher Örebro scores (indicative of higher risk of persistent pain) or longer duration of symptoms derived the largest benefits from individualized physical therapy relative to advice. Poorer coping also predicted larger benefits from individualized physical therapy in the univariate analysis.

CONCLUSION

These findings suggest that people with low back disorders could be preferentially targeted for individualized physical therapy rather than advice if they have higher back pain levels, longer duration of symptoms, or higher Örebro scores.

LEVEL OF EVIDENCE

2.

Assessing physical functioning on pain management programmes: the unique contribution of directly assessed physical performance measures and their relationship to self-reports

Physical functioning is a recommended outcome domain for pain management programmes. It can be assessed by self-report and by direct assessment of performance. Although physical performance measures may provide unique and useful information about patient functioning over and above self-report measures, it is not entirely clear which of the many possible performances to assess. This study investigated a battery of three directly assessed physical performance measures and their relationship to three currently used self-report measures of general health and functioning. The three performance measures were sensitive to treatment; patients performed significantly better on all three measures following completion of the pain management programme. The three performance measures were shown to represent a single underlying dimension, and there was a significant degree of overlap between them. The performance measures were shown to be relevant in explaining variation in the self-report measures, as well as to offer a clinically relevant different dimension of assessment to self-report. Future research could focus on developing performance-based measures that capture quality of movement and that are sensitive to relevant processes of therapeutic change.

Rational and design of an individual participant data meta-analysis of spinal manipulative therapy for chronic low back pain-a protocol

BACKGROUND

Chronic low back pain (LBP) is the leading cause of pain and disability, resulting in a major socioeconomic impact. The Cochrane Review which examined the effect of spinal manipulative therapy (SMT) for chronic LBP concluded that SMT is moderately effective, but was based on conventional meta-analysis of aggregate data. The use of individual participant data (IPD) from trials allows for a more precise estimate of the treatment effect and has the potential to identify moderators and/or mediators. The aim is (1) to assess the overall treatment effect of SMT for primary and secondary outcomes in adults with chronic LBP, (2) to determine possible moderation of baseline characteristics on treatment effect, (3) to identify characteristics of intervention (e.g., manipulation/mobilization) that influence the treatment effect, and (4) to identify mediators of treatment effects.

METHODS

All trials included in the Cochrane Review on SMT for chronic LBP will be included which were published after the year 2000, and the search will be updated. No restrictions will be placed on the type of comparison or size of the study. Primary outcomes are pain intensity and physical functioning. A dataset will be compiled consisting of individual trials and variables included according to a predefined coding scheme. Variables to be included are descriptive of characteristics of the study, treatment, comparison, participant characteristics, and outcomes at all follow-up periods. A one-stage approach with a mixed model technique based on the intention-to-treat principle will be used for the analysis. Subsequent analyses will focus on treatment effect moderators and mediators.

DISCUSSION

We will analyze IPD for LBP trials in which SMT is one of the interventions. IPD meta-analysis has been shown to be more reliable and valid than aggregate data meta-analysis, although this difference might also be attributed to the number of studies that can be used or the amount of data that can be utilized. Therefore, this project may identify important gaps in our knowledge with respect to prognostic factors of treatment effects.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015025714.

Development of a repository of individual participant data from randomized controlled trials of therapists delivered interventions for low back pain

Background

Individual patient data (IPD) meta‐analysis of existing randomized controlled trials (RCTs) is a promising approach to achieving sufficient statistical power to identify sub‐groups. We created a repository of IPD from multiple low back pain (LBP) RCTs to facilitate a study of treatment moderators. Due to sparse heterogeneous data, the repository needed to be robust and flexible to accommodate millions of data points prior to any subsequent analysis.

Methods

We systematically identified RCTs of therapist delivered intervention for inclusion to the repository. Some were obtained through project publicity. We requested both individual items and aggregate scores of all baseline characteristics and outcomes for all available time points. The repository is made up of a hybrid database: entity‐attribute‐value and relational database which is capable of storing sparse heterogeneous datasets. We developed a bespoke software program to extract, transform and upload the shared data.

Results

There were 20 datasets with more than 3 million data points from 9328 participants. All trials collected covariates and outcomes data at baseline and follow‐ups. The bespoke standardized repository is flexible to accommodate millions of data points without compromising data integrity. Data are easily retrieved for analysis using standard statistical programs.

Conclusions

The bespoke hybrid repository is complex to implement and to query but its flexibility in supporting datasets with varying sets of responses and outcomes with different data types is a worthy trade off. The large standardized LBP dataset is also an important resource useable by other LBP researchers.

Significance

A flexible adaptive database for pain studies that can easily be expanded for future researchers to map, transform and upload their data in a safe and secure environment. The data are standardized and harmonized which will facilitate future requests from other researchers for secondary analyses.

Identifying Treatment Effect Modifiers in the STarT Back Trial: A Secondary Analysis

Identification of patient characteristics influencing treatment outcomes is a top low back pain (LBP) research priority. Results from the STarT Back trial support the effectiveness of prognostic stratified care for LBP compared with current best care, however, patient characteristics associated with treatment response have not yet been explored. The purpose of this secondary analysis was to identify treatment effect modifiers within the STarT Back trial at 4-month follow-up (n = 688). Treatment response was dichotomized using back-specific physical disability measured using the Roland-Morris Disability Questionnaire (≥7). Candidate modifiers were identified using previous literature and evaluated using logistic regression with statistical interaction terms to provide preliminary evidence of treatment effect modification. Socioeconomic status (SES) was identified as an effect modifier for disability outcomes (odds ratio [OR] = 1.71, P = .028). High SES patients receiving prognostic stratified care were 2.5 times less likely to have a poor outcome compared with low SES patients receiving best current care (OR = .40, P = .006). Education level (OR = 1.33, P = .109) and number of pain medications (OR = .64, P = .140) met our criteria for effect modification with weaker evidence (.20 > P ≥ .05). These findings provide preliminary evidence for SES, education, and number of pain medications as treatment effect modifiers of prognostic stratified care delivered in the STarT Back Trial.

PERSPECTIVE

This analysis provides preliminary exploratory findings about the characteristics of patients who might least likely benefit from targeted treatment using prognostic stratified care for LBP.

Current and future perspectives on lumbar degenerative disc disease: a UK survey exploring specialist multidisciplinary clinical opinion

OBJECTIVES

Despite lumbar degenerative disc disease (LDDD) being significantly associated with non-specific low back pain and effective treatment remaining elusive, specialist multidisciplinary clinical stakeholder opinion remains unexplored. The present study examines the views of such experts.

DESIGN

A reliable and valid electronic survey was designed to establish trends using theoretical constructs relating to current assessment and management practices. Clinicians from the Society of Back Pain Research (SBPR) UK were invited to take part. Quantitative data were collated and coded using Bristol Online Surveys (BOS) software, and content analysis was used to systematically code and categorise qualitative data.

SETTING

Specialist multidisciplinary spinal interest group in the UK.

PARTICIPANTS

38/141 clinically active, multidisciplinary SBPR members with specialist spinal interest participated. Among them, 84% had >9 years postgraduate clinical experience.

INTERVENTIONS

None.

OUTCOME MEASURES

Frequency distributions were used to establish general trends in quantitative data. Qualitative responses were coded and categorised in relation to each theme and percentage responses were calculated.

RESULTS

LDDD symptom recurrence, in the absence of psychosocial influence, was associated with physical signs of joint stiffness (26%), weakness (17%) and joint hypermobility (6%), while physical factors (21%) and the ability to adapt (11%) were postulated as reasons why some experience pain and others do not. No one management strategy was supported exclusively or with consensus. Regarding effective modalities, there was no significant difference between allied health professional and medic responses (p=0.1-0.8). The future of LDDD care was expressed in terms of improvements in patient communication (35%), patient education (38%) and treatment stratification (24%).

CONCLUSIONS

Results suggest that multidisciplinary expert spinal clinicians appear to follow UK-based assessment guidelines with regard to recurrent LDDD; there are, however, inconsistencies in the management approaches supported. This reflects the current literature and the lack of specific, formalised guidance. LDDD treatment stratification and further research are explicitly supported.

Identifying back pain subgroups: developing and applying approaches using individual patient data collected within clinical trials

Background

There is good evidence that therapist-delivered interventions have modest beneficial effects for people with low back pain (LBP). Identification of subgroups of people with LBP who may benefit from these different treatment approaches is an important research priority.

Aim and objectives

To improve the clinical effectiveness and cost-effectiveness of LBP treatment by providing patients, their clinical advisors and health-service purchasers with better information about which participants are most likely to benefit from which treatment choices. Our objectives were to synthesise what is already known about the validity, reliability and predictive value of possible treatment moderators (patient factors that predict response to treatment) for therapist-delivered interventions; develop a repository of individual participant data from randomised controlled trials (RCTs) testing therapist-delivered interventions for LBP; determine which participant characteristics, if any, predict clinical response to different treatments for LBP; and determine which participant characteristics, if any, predict the most cost-effective treatments for LBP. Achieving these objectives required substantial methodological work, including the development and evaluation of some novel statistical approaches. This programme of work was not designed to analyse the main effect of interventions and no such interpretations should be made.

Methods

First, we reviewed the literature on treatment moderators and subgroups. We initially invited investigators of trials of therapist-delivered interventions for LBP with > 179 participants to share their data with us; some further smaller trials that were offered to us were also included. Using these trials we developed a repository of individual participant data of therapist-delivered interventions for LBP. Using this data set we sought to identify which participant characteristics, if any, predict response to different treatments (moderators) for clinical effectiveness and cost-effectiveness outcomes. We undertook an analysis of covariance to identify potential moderators to apply in our main analyses. Subsequently, we developed and applied three methods of subgroup identification: recursive partitioning (interaction trees and subgroup identification based on a differential effect search); adaptive risk group refinement; and an individual participant data indirect network meta-analysis (NWMA) to identify subgroups defined by multiple parameters.

Results

We included data from 19 RCTs with 9328 participants (mean age 49 years, 57% females). Our prespecified analyses using recursive partitioning and adaptive risk group refinement performed well and allowed us to identify some subgroups. The differences in the effect size in the different subgroups were typically small and unlikely to be clinically meaningful. Increasing baseline severity on the outcome of interest was the strongest driver of subgroup identification that we identified. Additionally, we explored the application of Bayesian indirect NWMA. This method produced varying probabilities that a particular treatment choice would be most likely to be effective for a specific patient profile.

Conclusions

These data lack clinical effectiveness or cost-effectiveness justification for the use of baseline characteristics in the development of subgroups for back pain. The methodological developments from this work have the potential to be applied in other clinical areas. The pooled repository database will serve as a valuable resource to the LBP research community.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme. This project benefited from facilities funded through Birmingham Science City Translational Medicine Clinical Research and Infrastructure Trials Platform, with support from Advantage West Midlands (AWM) and the Wolfson Foundation.

Validation of the German version of the STarT-Back Tool (STarT-G): a cohort study with patients from primary care practices

Background

Current research emphasizes the high prevalence and costs of low back pain (LBP). The STarT Back Tool was designed to support primary care decision making for treatment by helping to determine the treatment prognosis of patients with non-specific low back pain. The German version is the STarT-G. The cross-cultural translation of the tool followed a structured and widely accepted process but to date it was only partially validated with a small sample.

The aim of the study was to test the psychometric properties construct validity, discriminative ability, internal consistency and test-retest-reliability of the STarT-G and to compare them with values given for the original English version.

Methods

A consecutive cohort study with a two-week retest was conducted among patients with non-specific LBP, aged 18 to 60 years, from primary care practices. Questionnaires were collected before the first consultation, and two weeks later by post, using the following reference standards: the Roland and Morris disability questionnaire, the Tampa Scale of Kinesiophobia, the Pain Catastrophizing Scale and the Hospital Anxiety and Depression Scale. Psychometric properties examined included the tool’s discriminative abilities, whether the psychosocial subscale was one factor, internal consistency, item redundancy, test-retest reliability and floor and ceiling effects.

Results

There were 228 patients recruited with a mean age of 42.2 (SD 11.0) years, and 53 % were female. The areas under the curve (AUC) for discriminative ability ranged from 0.70 (STarT-G Subscale - Pain Catastrophizing Scale; CI95 0.63, 0.78) to 0.77 (STarT-G Total - Composite reference standard, CI95 0.60, 0.94). Factor loadings ranged from 0.49 to 0.74. Cronbach’s alpha testing the internal consistency and redundancy for the total/subscale scores were α = 0.52/0.55 respectively. The STarT-G test-retest reliability Kappa values for the total/subscale scores were 0.67/0.68 respectively. No floor or ceiling effects were present.

Conclusions

The STarT-G shows acceptable psychometric properties although not in exact agreement with the original English version. The items previously regarded as a psychosocial subscale may be better seen as an index of different individual psychosocial constructs. The relevance of using the tool at the point of consultation should be further examined.