A systematic review reveals that the credibility of subgroup claims in low back pain trials was low

The credibility of subgroup analyses reported in stroke trials is low: A systematic review

BACKGROUND

Subgroup analyses are widely used to evaluate the heterogeneity of treatment effects in randomized clinical trials. However, there is a limited investigation of the quality of prespecified and reported subgroup analyses in stroke trials. This study evaluated the credibility of subgroup analyses in stroke trials.

METHODS AND ANALYSIS

We searched Medline/PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the Web of Science from inception to 24 March 2021. Three reviewers screened, extracted, and analyzed the data from the publications. Primary publications of stroke trials that reported at least one subgroup effect and had published corresponding study protocols were included. The Instrument for Assessing the Credibility of Effect Modification Analyses (ICEMAN) was used to examine the quality of the subgroup effects reported, with each subgroup effect assigned a credibility rating ranging from very low to high. Subgroup effects with two or more "definitely no" responses received a low credibility rating. The risk of bias was assessed using the Cochrane Risk-of-Bias tool for randomized trials version 2.

RESULTS

Seventy-four articles met the inclusion criteria and reported a combined total of 647 subgroup effects. The median sample size was 1264 (interquartile range (IQR): 380-3876), and the median number of subgroups prespecified in the protocol was 6 (IQR: 2-10). Sixty-one (82%) studies used the univariate test of interaction. Of the total 647 subgroup effects reported in these studies, 319 (49%) were reported in acute stroke trials, while 423 (65%) had low credibility.

CONCLUSION

The quality of subgroup analysis reporting in stroke trials remains poor. More effort is needed to train trialists on the best methods for designing and performing subgroup analyses, and how to report the results.

TRIAL REGISTRATION NUMBER

We prospectively registered the review with International Prospective Register for Systematic Reviews (registration number: CRD42020223133).

Subgroup analyses in venous thromboembolism trials reporting pharmacological interventions: A systematic review

INTRODUCTION

Randomized controlled trials (RCTs) that conduct subgroup analyses have the potential to provide information on treatment decisions in specific groups of patients from heterogeneous populations. Although we understand several factors can modify the incidence of venous thromboembolism (VTE) and the benefit/risk ratio of anticoagulation treatments, further evidence is warranted to show the heterogeneity of treatment effects in different subgroups of patients.

AIMS

The primary purpose was to evaluate the appropriateness and interpretation of subgroup analysis performed on VTE RCTs reporting pharmacological interventions.

MATERIALS AND METHODS

A systematic review of RCTs published between January 2017 and January 2022 was conducted. Claims of subgroup effects were evaluated with predefined criteria. High-quality claims of subgroup effect were further analyzed and discussed.

RESULTS

Overall, 28 RCTs with a generally low bias risk were included. The purposes of the treatments included pharmacologic thromboprophylaxis (17), therapeutic dose anticoagulation (9), and catheter-directed pharmacologic thrombolysis (2). The evaluated subgroup analyses generally presented: a high number of subgroup analyses reported, a lack of prespecification, and a lack of usage of statistical tests for interaction. The authors reported 13 claims of subgroup effect; only two were considered potentially reliable to represent heterogeneity in the direction or magnitude of treatment effect.

CONCLUSIONS

Subgroup analyses of VTE RCTs reporting pharmacologic interventions are generally methodologically poor. Most claims of subgroup effect did not meet critical criteria and lacked credibility. Clinicians in this field may proceed with scepticism when assessing claims of subgroup effects due to methodological concerns and misleading interpretations.

Demographic and psychometric predictors associated with engagement in risk-associated alternative healthcare behaviours

This paper builds on prior work exploring the use of risk-associated alternative healthcare (RAAH) in Canada. RAAH uptake was surveyed to explore the characteristics of adult RAAH users and the value of established psychometric instruments previously used in alternative healthcare studies in predicting RAAH behaviours: the Control Beliefs Inventory (CBI), the Reward Responsiveness Behavioural Activation System (RBAS) scale, the Positive Attitudes to Science (PAS) scale, the Satisfaction with Orthodox Medicine (SOM) scale, and the brief version of the Susceptibility to Persuasion-II (StP-II-B) scale. Findings suggest RAAH is influenced by gender, age, income, education, employment, chronic illness status, and ethnicity. Engagement in some form of RAAH was common (around 40%) and the most common types of RAAH use reported were physical manipulation and herbal/nutritional supplement use. Other higher-risk AH activities (such as use of toxins and physically invasive procedures) were also reported by about 5% of respondents. The StP-II-B and PAS instruments were predictive of the likelihood of engagement in RAAH behaviours, as illustrated by higher risk tolerance, desire for novelty, positive attitude to advertising and social influence, and positive beliefs about science. The CBI, RBAS, and SOM instruments were not predictive overall. However, the CBI and SOM instruments were predictive of engagement with physical manipulative RAAH activities, while the RBAS was predictive of herbal/nutritional RAAH engagement. These findings can help inform health professionals' understanding of public health-seeking behaviours with respect to risk.

Single-group studies in leading physical therapy journals commonly make inappropriate conclusions regarding treatment effect modifiers. A systematic review

BACKGROUND

Characteristics that identify patients who respond differently to certain interventions are called treatment effect modifiers. Some studies inappropriately report the presence of treatment effect modifiers without adequate study designs.

OBJECTIVES

To evaluate what proportion of single-group studies published in leading physical therapy journals inappropriately report treatment effect modifiers, and to assess whether the proportion varies over time or between journals.

METHODS

A systematic review was conducted of studies published in eight leading physical therapy journals since 2000. Eligible studies were single-group studies (e.g., cohort study or secondary analysis of treatment arm of randomised controlled trial) that investigated any condition, treatment or outcome. Studies that suggested participants with certain baseline characteristics responded better/or worse to the treatment, were considered to have reported inappropriately. Studies reporting that participants with certain baseline characteristics had improved outcomes but did not state it was due to the treatment were considered to have reported appropriately. The proportion of inappropriate reporting was compared over time and between journals.

RESULTS

Of the 145 included studies, 73 (50.3%) were categorised as inappropriately reporting treatment effect modifiers. The proportion of inappropriate reporting was highest in the most recent period, 2018 - 2022 (59.6%) and 2006 - 2011 (55.6%). The proportion of inappropriate reporting varied substantially between journals from 0% (Journal of Physiotherapy) to 91.7% (Journal of Neurologic Physical Therapy).

CONCLUSIONS

A large proportion (50.3%) of single-arm studies in leading physical therapy journals inappropriately report treatment effect modifiers. This inappropriate reporting risks misleading clinicians when selecting interventions for individual patients.

Do imaging findings modify the effect of non-surgical treatment in patients with knee and hip osteoarthritis? A systematic literature review

OBJECTIVES

To review the available evidence on diagnostic imaging findings in knee and hip osteoarthritis (OA) as treatment effect modifiers in non-surgical OA interventions.

METHODS

MEDLINE, Embase and The Cochrane Central Register of Controlled Trials were searched from the earliest records published to 22 March 2022. Studies in knee and hip OA reporting subgroup analyses in randomised controlled trials with imaging findings as potential treatment effect modifiers were included. Studies were critically appraised using the Cochrane risk of bias tool and a subgroup analysis quality assessment.

RESULTS

Of 10 014 titles and abstracts screened, eight studies met the inclusion criteria, six on knee OA and two on hip OA. The studies investigated effect modifiers in exercise therapy, intra-articular injections and unloading shoes. Imaging findings assessed as potential treatment effect modifiers were radiographic OA severity, hip effusion (ultrasound), bone marrow lesions and meniscal pathology (MRI). Two studies fulfilled the methodological quality criteria for assessing effect modification. One reported that radiographic knee OA severity modified the effect of unloading shoes on walking pain. Those with more severe radiographic knee OA had a greater response to shoe inserts. One reported no interaction between radiographic OA severity or joint effusion and the effect of intraarticular injections of corticosteroid or hyaluronic acid in hip OA, indicating no difference in response in people with greater hip joint effusion or radiographic OA severity compared with those with less severe joint disease.

CONCLUSION

Overall, methodological limitations and very few studies do not permit conclusions on diagnostic imaging findings as effect modifiers in non-surgical interventions in knee and hip OA.Radiographic severity of knee OA potentially modifies the effect of unloading shoes.

PROSPERO REGISTRATION NUMBER

CRD42020181934.

Public and patient perceptions of diagnostic labels for non-specific low back pain: a content analysis

PURPOSE

An online randomised experiment found that the labels lumbar sprain, non-specific low back pain (LBP), and episode of back pain reduced perceived need for imaging, surgery and second opinions compared to disc bulge, degeneration, and arthritis among 1447 participants with and without LBP. They also reduced perceived seriousness of LBP and increased recovery expectations.

METHODS

In this study we report the results of a content analysis of free-text data collected in our experiment. We used two questions: 1. When you hear the term [one of the six labels], what words or feelings does this make you think of? and 2. What treatment (s) (if any) do you think a person with [one of the six labels] needs? Two independent reviewers analysed 2546 responses.

RESULTS

Ten themes emerged for Question1. Poor prognosis emerged for disc bulge, degeneration, and arthritis, while good prognosis emerged for lumbar sprain, non-specific LBP, and episode of back pain. Thoughts of tissue damage were less common for non-specific LBP and episode of back pain. Feelings of uncertainty frequently emerged for non-specific LBP. Twenty-eight treatments emerged for Question2. Surgery emerged for disc bulge, degeneration, and arthritis compared to lumbar sprain, non-specific LBP, and episode of back pain. Surgery did not emerge for non-specific LBP and episode of back pain.

CONCLUSION

Our results suggest that clinicians should consider avoiding the labels disc bulge, degeneration and arthritis and opt for labels that are associated with positive beliefs and less preference for surgery, when communicating with patients with LBP.

Treatment-based classification for low back pain: systematic review with meta-analysis

OBJECTIVE

To systematically review the effects of treatment-based classification (TBC) in patients with specific and nonspecific acute, subacute and chronic low back pain.

METHODS

The following databases were searched: MEDLINE, EMBASE, PsycINFO, Global Health, CENTRAL, Web of Science, CINAHL, SPORTDiscus, PEDro and WHO from inception up to December 2021. We used the PEDro scale, the TIDieR checklist and the GRADE approach to evaluate the risk of bias, quality on reporting and the certainty of the evidence, respectively.

RESULTS

Twenty-three trials (pooled n = 2,649) met the inclusion criteria. We have identified a total of 22 comparisons and 134 estimates of treatment effects. There was a very large heterogeneity with regards to the comparison groups. Most of individual trials had low risk of bias with a mean score of 6.8 (SD = 1.3) on a 0-10 scale. The certainty of evidence for most comparisons was low, which indicates that more high quality and robust trials are needed. We were able to pool the data using a meta-analysis approach for only two comparisons (TBC versus mobility exercises in patients with acute low back pain and traction for patients with sciatica). In general, the TBC approach seems to be useful for patients with acute low back pain, sciatica and with spinal stenosis. We strongly suggest readers to carefully read our summary of findings table for further details on each comparison.

CONCLUSION

The TBC approach seems to be useful for patients with acute low back pain, sciatica and with spinal stenosis.

Subgroup Analysis in Pulmonary Hypertension-Specific Therapy Clinical Trials: A Systematic Review

Pulmonary hypertension (PH) treatment decisions are driven by the results of randomized controlled trials (RCTs). Subgroup analyses are often performed to assess whether the intervention effect will change due to the patient’s characteristics, thus allowing for individualized decisions. This review aimed to evaluate the appropriateness and interpretation of subgroup analyses performed in PH-specific therapy RCTs published between 2000 and 2020. Claims of subgroup effects were evaluated with prespecified criteria. Overall, 30 RCTs were included. Subgroup analyses presented: a high number of subgroup analyses reported, lack of prespecification, and lack of interaction tests. The trial protocol was not available for most RCTs; significant differences were found in those articles that published the protocol. Authors reported 13 claims of subgroup effect, with 12 claims meeting four or fewer of Sun’s criteria. Even when most RCTs were generally at low risk of bias and were published in high-impact journals, the credibility and general quality of subgroup analyses and subgroup claims were low due to methodological flaws. Clinicians should be skeptical of claims of subgroup effects and interpret subgroup analyses with caution, as due to their poor quality, these analyses may not serve as guidance for personalized care.

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.

Peripheral and Central Pathological Mechanisms of Chronic Low Back Pain: A Narrative Review

Chronic low back pain (CLBP), lasting >3 months, is the end result of multiple pathogenic factors. Unfortunately, little is known about CLBP pathogenesis, which limits its advancements in clinical therapy and disease management. This paper summarizes the known pathological axes of CLBP, involving both peripheral and central systems. In particular, this paper details injurious nerve stimulation, inflammation-induced peripheral pathway, and central sensitization. Lumbar components, such as intervertebral disc (IVD), facet joints, muscles, fascia, ligaments, and joint capsules, contain pain receptors called nociceptors. Degeneration of the aforementioned lumbar components activates inflammatory pathways, which can directly damage nerves, lower nociceptor threshold to fire action potentials (AP), and cause pain. Additionally, damaged lumbar IVDs and endplates can also lead to the pathologic invasion of nerve growth and innervation, followed by the compression of herniated IVDs on nerve roots, thereby causing traumatic neuropathic pain. The central mechanism of CLBP involves alteration of the sensory processing of the brain and malfunction of the descending pain modulatory system, which facilitates pain amplification in the center nervous system (CNS). Lastly, abnormalities in the brain biochemical metabolism, activation of glial cells, and subsequent inflammation also play important roles in CLBP development. Taken together, inflammation plays an important role in both peripheral and central sensitization of CLBP. Due to the heterogeneity of CLBP, its pathological mechanism remains complex and difficult to understand. Therefore, it is a worthy field for future research into the subcomponents of CLBP pathogenesis, in order to distinguish the specific form of the disease, identify its origins, and develop corresponding highly effective comprehensive therapy against CLBP.

Self-reported prognostic factors in adults reporting neck or low back pain: An umbrella review

BACKGROUND

Numerous systematic reviews have attempted to synthesize evidence on prognostic factors for predicting future outcomes such as pain, disability and return-to-work/work absence in neck and low back pain populations.

DATABASES AND DATATREATMENT

An umbrella review of systematic reviews was conducted to summarize the magnitude and quality of the evidence for each prognostic factor investigated. Searches were limited to the last 10 years (2008-11th April 2018, updated 28th September 2020). A two-stage approach was undertaken: in stage one, data on prognostic factors was extracted from systematic reviews identified from the systematic search that met the inclusion criteria. Where a prognostic factor was investigated in ≥1 systematic review and where 50% or more of those reviews found an association between the prognostic factor and one of the outcomes of interest, it was taken forward to stage two. In stage two, additional information extracted included the strength of association found, consistency of effects and risk of bias. The GRADE approach was used to grade confidence in the evidence.

RESULTS

Stage one identified 41 reviews (90 prognostic factors), with 35 reviews (25 prognostic factors) taken forward to stage two. Seven prognostic factors (disability/activity limitation, mental health; pain intensity; pain severity; coping; expectation of outcome/recovery and fear-avoidance) were judged as having moderate confidence for robust findings.

CONCLUSIONS

Although there was conflicting evidence for the strength of association with outcome, these factors may be used for identifying vulnerable subgroups or people able to self-manage. Further research can investigate the impact of using such prognostic information on treatment/referral decisions and patient outcomes.

Effectiveness of treatments for acute and subacute mechanical non-specific low back pain: a systematic review with network meta-analysis

Objective

To assess the effectiveness of interventions for acute and subacute non-specific low back pain (NS-LBP) based on pain and disability outcomes.

Design

A systematic review of the literature with network meta-analysis.

Data sources

Medline, Embase and CENTRAL databases were searched from inception until 17 October 2020.

Eligibility criteria for selecting studies

Randomised clinical trials (RCTs) involving adults with NS-LBP who experienced pain for less than 6 weeks (acute) or between 6 and 12 weeks (subacute).

Results

Forty-six RCTs (n=8765) were included; risk of bias was low in 9 trials (19.6%), unclear in 20 (43.5%), and high in 17 (36.9%). At immediate-term follow-up, for pain decrease, the most efficacious treatments against an inert therapy were: exercise (standardised mean difference (SMD) −1.40; 95% confidence interval (CI) −2.41 to –0.40), heat wrap (SMD −1.38; 95% CI −2.60 to –0.17), opioids (SMD −0.86; 95% CI −1.62 to –0.10), manual therapy (SMD −0.72; 95% CI −1.40 to –0.04) and non-steroidal anti-inflammatory drugs (NSAIDs) (SMD −0.53; 95% CI −0.97 to –0.09). Similar findings were confirmed for disability reduction in non-pharmacological and pharmacological networks, including muscle relaxants (SMD -0.24; 95% CI -0.43 to -0.04). Mild or moderate adverse events were reported in the opioids (65.7%), NSAIDs (54.3%) and steroids (46.9%) trial arms.

Conclusion

With uncertainty of evidence, NS-LBP should be managed with non-pharmacological treatments which seem to mitigate pain and disability at immediate-term. Among pharmacological interventions, NSAIDs and muscle relaxants appear to offer the best harm–benefit balance.

The quality of subgroup analyses in chronic pain randomized controlled trials: a methodological review

The quality of subgroup analyses (SGAs) in chronic non-cancer pain trials is uncertain. The purpose of this study was to address this issue. We conducted a comprehensive search in MEDLINE and EMBASE from January 2012 to September 2018 to identify eligible trials. Two pairs of reviewers assessed the quality of the SGAs and the credibility of subgroup claims using the 10 criteria developed by Sun et al. in 2012. The associations between the quality of the SGAs and the studies' characteristics including risk of bias, funding sources, sample size, and the latest impact factor, were assessed using multivariable logistic regression. Our search retrieved 3,401 articles of which 66 were eligible. The total number of SGAs was 177 of which 52 (29.4%) made a subgroup claim. Of these, only 15 (8.5%) were evaluated as being of high quality. Among the 30 SGAs that claimed subgroup effects using an appropriate method of performing interaction tests, the credibility of only 5 were assessed as high. None of the subgroup claims met all the credibility criteria. No significant association was found between the quality of SGAs and the studies' characteristics. The quality of the SGAs performed in chronic pain trials was poor. To enhance the quality of SGAs, scholars should consider the developed criteria when designing and conducting trials, particularly those which need to be specified a priori .

Subgroup analysis in haematologic malignancies phase III clinical trials: A systematic review

AIMS

To assess the appropriateness of the use and interpretation of subgroup analysis in haematology randomized clinical trials (RCTs).

METHOD

A systematic review of Medline, including haematology phase III RCTs published between January 2013 and October 2019, was carried out to identify reported subgroup analysis. Information related to trial characteristics, subgroup analysis and claims of subgroup difference were collected.

RESULTS

The initial search identified 1622 studies. A total of 98 studies reporting subgroup analyses were identified. Of those, 24 RCT reported 46 claims of subgroup difference. Among them, 44 were claims for the primary outcome, of which 25 were considered strong claims and 17 were considered suggestions of a possible effect. Authors included subgroup variables for the primary outcome measured at baseline for 38 claims (n = 86.36%), used a subgroup variable as a stratification factor at randomization for 15 (34.09%), clearly prespecified their hypothesis for 11 (25%), the subgroup effect was one of a small number of hypothesised effects tested (≤ 5) for 17 (38.64%), carried out a test of interaction that provide statistically significant for 18 (40.91%), documented replication of a subgroup effect with previously related studies for 11 (25%), identified the consistency of a subgroup effect across related outcome for 10 (22.72%) and provided a biological rationale for the effect for 8 (18.18%). Of the 44 claims for the primary outcome, 34 (77.27%) met four or fewer of the 10 credibility criteria.

CONCLUSION

The subgroup claims reported in haematology RCTs lack credibility, even when the claims are strong. Information about subgroup difference should be interpreted cautiously.

Analgesic medicines for adults with low back pain: protocol for a systematic review and network meta-analysis

BACKGROUND

There is limited evidence for the comparative effectiveness of analgesic medicines for adults with low back pain. This systematic review and network meta-analysis aims to determine the analgesic effect, safety, acceptability, effect on function, and relative rank according to analgesic effect, safety, acceptability, and effect on function of a single course of [an] analgesic medicine(s) or combination of these medicines for people with low back pain.

METHODS

We will include published and unpublished randomised trials written in any language that compare an analgesic medicine to either another medicine, placebo/sham, or no intervention in adults with low back pain, grouped according to pain duration: acute (fewer than 6 weeks), sub-acute (6 to 12 weeks), and chronic (greater than 12 weeks). The co-primary outcomes are pain intensity following treatment and safety (adverse events). The secondary outcomes are function and acceptability (all-cause dropouts). We will perform a network meta-analysis to compare and rank analgesic medicines. We will form judgements of confidence in the results using the Confidence in Network Meta-Analysis (CINeMA) methodology.

DISCUSSION

This network meta-analysis will establish which medicine, or combination of medicines, is most effective for reducing pain and safest for adults with low back pain.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019145257.

Characteristics and interpretation of subgroup analyses based on tumour characteristics in randomised trials testing target-specific anticancer drugs: design of a systematic survey

BACKGROUND

Target-specific anticancer drugs are under rapid development. Little is known, however, about the risk of administering target-specific drugs to patients who have tumours with molecular alterations or other characteristics that can make the drug ineffective or even harmful. An increasing number of randomised clinical trials (RCTs) investigating target-specific anticancer drugs include subgroup analyses based on tumour characteristics. Such subgroup analyses have the potential to be more credible and influential than subgroup analyses based on traditional factors such as sex or tumour stage. In addition, they may more frequently lead to qualitative subgroup effects, that is, show benefit in one but harm in another subgroup of patients (eg, if the tumour characteristic makes the drug ineffective or even enhance tumour growth). If so, subgroup analyses based on tumour characteristics would be highly relevant for patient safety. The aim of this study is to systematically assess the frequency and characteristics of subgroup analyses based on tumour characteristics, the frequency of qualitative subgroup effects, their credibility, and the interpretations that investigators and guidelines developers report.

METHODS AND ANALYSIS

We will perform a systematic survey of 433 RCTs testing the effect of target-specific anticancer drugs. Teams of methodologically trained investigators and oncologists will identify eligible studies, extract relevant data and assess the credibility of putative subgroup effects using a recently developed formal instrument. We will systematically assess how trial investigators interpret apparent subgroup effects based on tumour characteristics and the extent to which they influence subsequent practice guidelines. Our results will provide empirical data characterising an increasingly used type of subgroup analysis in cancer trials and its potential impact on precision medicine to predict benefit or harm.

ETHICS AND DISSEMINATION

Formal ethical approval is not required for this study. We will disseminate the findings in a peer-reviewed and open-access journal publication.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Exercise treatment effect modifiers in persistent low back pain: an individual participant data meta-analysis of 3514 participants from 27 randomised controlled trials

Background

Low back pain is one of the leading causes of disability worldwide. Exercise therapy is widely recommended to treat persistent non-specific low back pain. While evidence suggests exercise is, on average, moderately effective, there remains uncertainty about which individuals might benefit the most from exercise.

Methods

In parallel with a Cochrane review update, we requested individual participant data (IPD) from high-quality randomised clinical trials of adults with our two primary outcomes of interest, pain and functional limitations, and calculated global recovery. We compiled a master data set including baseline participant characteristics, exercise and comparison characteristics, and outcomes at short-term, moderate-term and long-term follow-up. We conducted descriptive analyses and one-stage IPD meta-analysis using multilevel mixed-effects regression of the overall treatment effect and prespecified potential treatment effect modifiers.

Results

We received IPD for 27 trials (3514 participants). For studies included in this analysis, compared with no treatment/usual care, exercise therapy on average reduced pain (mean effect/100 (95% CI) −10.7 (−14.1 to –7.4)), a result compatible with a clinically important 20% smallest worthwhile effect. Exercise therapy reduced functional limitations with a clinically important 23% improvement (mean effect/100 (95% CI) −10.2 (−13.2 to –7.3)) at short-term follow-up. Not having heavy physical demands at work and medication use for low back pain were potential treatment effect modifiers—these were associated with superior exercise outcomes relative to non-exercise comparisons. Lower body mass index was also associated with better outcomes in exercise compared with no treatment/usual care. This study was limited by inconsistent availability and measurement of participant characteristics.

Conclusions

This study provides potentially useful information to help treat patients and design future studies of exercise interventions that are better matched to specific subgroups.

Protocol publication

https://doi.org/10.1186/2046-4053-1-64

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.

A systematic survey identified 36 criteria for assessing effect modification claims in randomized trials or meta-analyses

OBJECTIVE

The objective of the study was to systematically survey the methodological literature and collect suggested criteria for assessing the credibility of effect modification and associated rationales.

STUDY DESIGN AND SETTING

We searched MEDLINE, Embase, and WorldCat up to March 2018 for publications providing guidance for assessing the credibility of effect modification identified in randomized trials or meta-analyses. Teams of two investigators independently identified eligible publications and extracted credibility criteria and authors' rationale, reaching consensus through discussion. We created a taxonomy of criteria that we iteratively refined during data abstraction.

RESULTS

We identified 150 eligible publications that provided 36 criteria and associated rationales. Frequent criteria included significant test for interaction (n = 54), a priori hypothesis (n = 49), providing a causal explanation (n = 47), accounting for multiplicity (n = 45), testing a small number of effect modifiers (n = 38), and prespecification of analytic details (n = 39). For some criteria, we found more than one rationale; some criteria were connected through a common rationale. For some criteria, experts disagreed regarding their suitability (e.g., added value of stratified randomization; trustworthiness of biologic rationales).

CONCLUSION

Methodologists have expended substantial intellectual energy providing criteria for critical appraisal of apparent effect modification. Our survey highlights popular criteria, expert agreement and disagreement, and where more work is needed, including testing criteria in practice.

Association Between Clinical Tests Related to Motor Control Dysfunction and Changes in Pain and Disability After Lumbar Stabilization Exercises in Individuals With Chronic Low Back Pain

OBJECTIVE

To investigate whether clinical tests used to detect motor control dysfunction can predict improvements in pain and disability in patients with chronic nonspecific low back pain (LBP) who have undergone an 8-week lumbar stabilization exercise program.

STUDY DESIGN

A prospective cohort study.

SETTING

Outpatient physical therapy university clinic.

PARTICIPANTS

Seventy people with chronic nonspecific LBP were recruited, and 64 completed the exercise program (N=64).

INTERVENTIONS

The lumbar stabilization program was provided twice a week for 8 weeks.

MAIN OUTCOME MEASURES

Pain intensity (11-point numerical rating scale) and disability (Roland Morris Disability Questionnaire) and clinical tests, such as the Deep Muscle Contraction (DMC) scale, Clinical Test of Thoracolumbar Dissociation (CTTD), and Passive Lumbar Extension (PLE) test. Univariate and multivariate linear regression models were used in the prediction analysis.

RESULTS

Mean changes in pain intensity and disability following the 8-week stabilization program were -3.8 (95% confidence interval [CI], -3.2 to -4.4) and -7.4 (95% CI, -6.3 to -8.5), respectively. Clinical test scores taken at baseline did not predict changes in pain and disability at 8-week follow-up.

CONCLUSION

Our findings revealed that the DMC scale, CTTD, PLE test, clinical tests used to assess motor control dysfunction, do not predict improvements in pain and disability in patients with chronic nonspecific LBP following an 8-week lumbar stabilization exercise program.

An international survey of the comprehensiveness of the McKenzie classification system and the proportions of classifications and directional preferences in patients with spinal pain

BACKGROUND

Classification of spinal pain has been a key goal identified in the research. However it is not clear if existing classification systems are comprehensive.

OBJECTIVE

To examine the comprehensiveness and distribution of classifications within the McKenzie classification system (MDT), and the directional preference in consecutive patients with spine pain.

STUDY DESIGN

Prospective, observational study.

METHODS

Clinicians with a Diploma in MDT provided data on patients that they had assessed, classified, managed, and then confirmed their classification at discharge. They provided data on the spinal area, the MDT classification, and the loading strategy used in management.

RESULTS

Fifty-four clinicians from at least 15 different countries provided data on 750 patients: lumbar 64.8%, cervical 29.6%, thoracic 5.6%. The distribution of classifications was as follows: Derangement 75.4%, OTHER 22.8%, Dysfunction 1.7%, Postural syndrome 0.1%. In Derangements 82.5% had a directional preference for extension, 12.9% for lateral forces, and 4.6% for flexion. Those patients classified as one of the OTHER subgroups were given specific classifications.

CONCLUSION

Derangement was the most common classification and extension was by far the most common directional preference. A substantial proportion were classified as OTHER subgroups, for whom management is less straightforward.

Guideline recommendations on the pharmacological management of non-specific low back pain in primary care - is there a need to change?

INTRODUCTION

Analgesic drugs are often prescribed to patients with non-specific low back pain (NSLBP). Recommendations for non-invasive pharmacological management of NSLBP from recent clinical practice guidelines were compared with each other and with the best available evidence on drug efficacy. Areas covered: Recommendations concerning opioids, non-steroidal anti-inflammatory drugs (NSAIDs), paracetamol, antidepressants, anticonvulsants and muscle relaxants from national primary care guidelines published within the last 3 years were included in this review. For each pharmacological treatment, the most recent systematic review was included as the best available evidence on drug efficacy and common adverse effects were summarized. Expert opinion: Although differences exist between guidelines, publications are universally moving away from pharmacotherapy due to the limited efficacy and the risk of adverse effects. NSAIDs have replaced paracetamol as the first choice analgesics for NSLBP in many guidelines. Opioids are generally considered to be a last resort, but opioid prescriptions have been increasing over recent years. Upcoming guideline updates should explicitly shift their focus from pain to function and from pharmacotherapy to non-pharmacological treatments; patient education is important to make sure NSLBP patients accept these changes. To improve the quality of NSLBP care, the evidence-practice gap should be closed through guideline implementation strategies.

Effect of subgroup-specific multimodal therapy on chronic spinal back pain and function-a prospective inpatient multicentre clinical trial in Germany

Treatment modalities of spinal pain patients are discussed diversely, and different multimodal therapy programs have been developed. Purpose of the present study was to evaluate therapy outcome and effectiveness of an inpatient interdisciplinary and multimodal treatment program.This prospective multicentre clinical trial has been performed with patients from orthopedic hospitals receiving a functional musculoskeletal therapy pathway. Outcome measures were pain intensity and back-specific function (Oswestry Disability Index) before (T1) and after the intervention (T2) as well as after 6 and 12 months (T3, T4). Statistical approach included parametric (t test) and nonparametric (Wilcoxon-test) tests and the calculation of effect sizes. Additionally, a statistical subgroup analysis based on selected parameters (degree of pain chronicity, gender, and age) was performed using linear mixed models.In total, 249 patients (42.6% men, 57.4% women) with spinal pain were included, 133 patients were accessible for follow-up at T3 and 106 patients at T4.Average pain (AP) reduced significantly (P <.001) from T1 to T4 with an effect size of 0.99. Back-specific function also improved (P <.001) over all measuring time points (TP) (effect size: 0.63). Furthermore, the statistical subgroup analysis demonstrated the efficacy of the treatment concept within the subgroup parameters chronicity degree and age.A functional musculoskeletal therapy pathway including treatment of musculoskeletal dysfunctions appears to be beneficial in terms of treating pain and function. Pain chronicity and age seems to be factors influencing therapy outcome. Further studies are needed to examine the superiority of these inpatient programs for back pain including control groups.

Credibility of subgroup analyses by socioeconomic status in public health intervention evaluations: An underappreciated problem?

There is increasing interest amongst researchers and policy makers in identifying the effect of public health interventions on health inequalities by socioeconomic status (SES). This issue is typically addressed in evaluation studies through subgroup analyses, where researchers test whether the effect of an intervention differs according to the socioeconomic status of participants. The credibility of such analyses is therefore crucial when making judgements about how an intervention is likely to affect health inequalities, although this issue appears to be rarely considered within public health. The aim of this study was therefore to assess the credibility of subgroup analyses in published evaluations of public health interventions. An established set of 10 credibility criteria for subgroup analyses was applied to a purposively sampled set of 21 evaluation studies, the majority of which focussed on healthy eating interventions, which reported differential intervention effects by SES. While the majority of these studies were found to be otherwise of relatively high quality methodologically, only 8 of the 21 studies met at least 6 of the 10 credibility criteria for subgroup analysis. These findings suggest that the credibility of subgroup analyses conducted within evaluations of public health interventions' impact on health inequalities may be an underappreciated problem.

Is osteoarthritis one disease or a collection of many?

OA is a multifaceted and heterogeneous syndrome that may be amenable to tailored treatment. There has been an increasing focus within the OA research community on the identification of meaningful OA phenotypes with potential implications for prognosis and treatment. Experimental and clinical data combined with sophisticated statistical approaches have been used to characterize and define phenotypes from the symptomatic and structural perspectives. An improved understanding of the existing phenotypes based on underlying disease mechanisms may shed light on the distinct entities that make up the disease. This narrative review provides an updated summary of the most recent advances in this field as well as limitations from previous approaches that can be addressed in future studies.

Knee osteoarthritis phenotypes and their relevance for outcomes: a systematic review

OBJECTIVE

To systematically review the literature for studies investigating knee osteoarthritis (OA) phenotypes to examine what OA characteristics are relevant for phenotyping.

METHODS

A comprehensive search was performed in Medline, EMBASE, Web of Sciences, CINAHL, and Scopus databases from inception to September 2016. Inclusion was limited to observational studies of individuals with symptomatic knee OA that identified phenotypes based on any OA characteristics and assessed their association with clinically important outcomes. A descriptive synthesis of the data was performed.

RESULTS

Of the 2777 citations retrieved, 34 studies were included. Clinical phenotypes were investigated most frequently, followed by laboratory, imaging and aetiologic phenotypes. Eight studies defined subgroups based on outcome trajectories (pain, function and radiographic progression trajectories). Most studies used a single patient or disease characteristic to identify patients subgroups while five included characteristics from multiple domains. We found evidence from multiple studies suggesting that pain sensitization, psychological distress, radiographic severity, body mass index (BMI), muscle strength, inflammation and comorbidities are associated with clinically distinct phenotypes. Gender, obesity and other metabolic abnormalities, the pattern of cartilage damage, and inflammation may be implicated in delineating distinct structural phenotypes. Only a few studies investigated the external validity of the phenotypes or their prospective validity using longitudinal outcomes.

CONCLUSIONS

There is marked heterogeneity in the data selected by the studies investigating knee OA phenotypes. We identified the phenotypic characteristics that can be considered for a comprehensive phenotype classification in future studies. A framework for the investigation of phenotypes could be useful for future studies.

PROTOCOL REGISTRATION

PROSPERO CRD42016036220.

Physical Therapy Management of Patients With Chronic Low Back Pain and Hip Abductor Weakness

BACKGROUND AND PURPOSE

Hip abductor dysfunction is common in individuals with chronic low back pain (CLBP). Previous research investigating abductor strengthening in the heterogeneous CLBP population is sparse and has failed to target those patients most likely to benefit. The aim of the current case series was to describe the physical therapy management and outcomes of 3 patients with CLBP matching a previously identified subgroup characterized by substantial hip abductor weakness.

CASE DESCRIPTION

Three nonconsecutive patients with CLBP-a 77-year-old man, a 78-year-old woman, and an 85-year-old woman-were treated in an outpatient physical therapy clinic. All 3 patients matched a previously identified CLBP subgroup characterized by substantial hip abductor weakness.

INTERVENTION

Patients were treated using a targeted exercise approach consisting mostly of hip abductor strengthening for 11 to 17 visits over 8 to 10 weeks. Patients received additional treatments including heel lift and pain neuroscience education when indicated.

OUTCOMES

By discharge, all patients had made clinically important improvements in pain (3- to 7-point reduction on the Numeric Pain Rating Scale), function (10- to 16-point change on the Modified Oswestry Disability Index), and perceived improvement (6-7 on Global Rating of Change Scale). Lumbar range of motion was painless, and hip abductor strength was improved from 2+/5 to 3+/5 in all 3 patients. These gains were maintained at 3-month follow-up.

DISCUSSION

The current case series describes the use of a targeted exercise approach consisting mostly of hip abductor strengthening in a group of patients with CLBP and hip abductor weakness. The results indicated that this approach may be effective in reducing pain and improving function, particularly for older patients.

Reconceptualising manual therapy skills in contemporary practice

With conflicting evidence regarding the effectiveness of manual therapy calls have arisen within some quarters of the physiotherapy profession challenging the continued use of manual skills for assessment and treatment. A reconceptualisation of the importance of manual examination findings is put forward, based upon a contemporary understanding of pain science, rather than considering these skills only in terms of how they should "guide" manual therapy interventions. The place for manual examination findings within complex, multidimensional presentations is considered using vignettes describing the presentations of five people with low back pain. As part of multidimensional, individualised management, the balance of evidence relating to the effectiveness, mechanisms of action and rationale for manual skills is discussed. It is concluded that if manual examination and therapeutic skills are used in a manner consistent with a contemporary understanding of pain science, multidimensional patient profiles and a person-centred approach, their selective and judicious use still has an important role.

March 2017 Letters to the Editor-in-Chief

Letters to the Editor-in-Chief of JOSPT as follows: "Regarding 'Unraveling the Complexity of Low Back Pain'" with Authors' Response "Beall's List Has Vanished: What Next?" with Editor-in-Chief Response J Orthop Sports Phys Ther 2017;47(3):219-223. doi:10.2519/jospt.2017.0202.

Outcomes of Patients With Acute Low Back Pain Stratified by the STarT Back Screening Tool: Secondary Analysis of a Randomized Trial

BACKGROUND

The impact of physical therapy on the outcomes of patients with acute low back pain (LBP) stratified by the STart Back Screening Tool (SBST) is unclear.

OBJECTIVE

The purpose of this study was to compare the outcomes of patients with acute LBP who were stratified as medium or high risk.

DESIGN

This was a secondary analysis of a randomized trial.

SETTING

Patients were recruited between March 2011 and November 2013 from primary care clinics in Salt Lake City, Utah.

PARTICIPANTS

One hundred eighty-one participants with acute LBP who were stratified as medium risk (n = 120) or high risk (n = 61) by the SBST were included. They were aged 18 through 60 years, with duration of symptoms less than 16 days, no symptoms below the knee, no treatment for LBP in the past 6 months, and an Oswestry Disability Index (ODI) score of 20% or greater.

INTERVENTION

After participants received education on how to manage their LBP, they were randomized to receive usual care (n = 97) by their primary care provider or early intervention (n = 84) by a physical therapist.

MEASUREMENTS

The primary (3-month ODI score) outcome measure was obtained at baseline and at 4 weeks, 3 months, and 1 year.

RESULTS

No differences were detected in the effect of intervention between participants stratified as medium or high risk. For the high-risk subgroup, there was a significant difference between the early intervention and usual care groups for the 3-month ODI (mean difference = -5.87 [95% CI = -11.24, -0.50]) favoring early intervention.

LIMITATIONS

The primary study was not designed to examine the SBST.

CONCLUSIONS

Patients with acute LBP stratified as high risk seem likely to respond well to one session of education. They may experience additional benefit by 3 months from evidence-based physical therapy treatments. These effects disappear at 1 year.

Subgrouping Patients With Nonspecific Low Back Pain: Hope or Hype?

Clinicians and clinical researchers share a common goal of achieving better outcomes for patients with low back pain (LBP). For that, randomized controlled trials and systematic reviews are the most reliable study designs to determine the effects of interventions. Subgroup analyses in these research designs have been used to examine treatment-effect modification across subgroups defined by patient characteristics. In this Viewpoint, the authors present supporting and opposing arguments for the subgrouping approach in nonspecific LBP, considering the progress made so far in the LBP field and the relevant literature in adjacent fields. J Orthop Sports Phys Ther 2017;47(2):44-48. doi:10.2519/jospt.2017.0602.

February 2017 Letter to the Editor-in-Chief

Letter to the Editor-in-Chief of JOSPT as follows: "Regarding the Complexity of Low Back Pain" with Authors' Response J Orthop Sports Phys Ther 2017;47(2):126-129. doi:10.2519/jospt.2017.0201.