How to Interpret Effect Sizes for Biopsychosocial Outcomes and Implications for Current Research.

Biopsychosocial factors are associated with pain, but they can be difficult to compare. One way of comparing them is to use standardized mean differences. Previously, these effects sizes have been termed as small, medium, or large, if they are bigger than or equal to, respectively, .2, .5, or .8. These cut-offs are arbitrary and recent evidence showed that they need to be reconsidered. We argue it is necessary to determine cut-offs for each biopsychosocial factor. To achieve this, we propose 3 potential approaches: 1) examining, for each factor, how the effect size differs depending upon disease severity; 2) using an existing minimum clinically important difference to anchor the large effect size; and 3) define cut-offs by comparing data from people with and without pain. This is important for pain research, as exploring these methodologies has potential to improve comparability of biopsychosocial factors and lead to more directed treatments. We note assumptions and limitations of these methods that should also be considered. PERSPECTIVE: Standardized mean differences can estimate effect sizes between groups and could theoretically allow for comparison of biopsychosocial factors. However, common thresholds to define effect sizes are arbitrary and likely differ based on outcome. We propose methods that could overcome this and be used to derive biopsychosocial outcome-specific effect sizes.

Evidence- and data-driven classification of low back pain via artificial intelligence: Protocol of the PREDICT-LBP study.

In patients presenting with low back pain (LBP), once specific causes are excluded (fracture, infection, inflammatory arthritis, cancer, cauda equina and radiculopathy) many clinicians pose a diagnosis of non-specific LBP. Accordingly, current management of non-specific LBP is generic. There is a need for a classification of non-specific LBP that is both data- and evidence-based assessing multi-dimensional pain-related factors in a large sample size. The "PRedictive Evidence Driven Intelligent Classification Tool for Low Back Pain" (PREDICT-LBP) project is a prospective cross-sectional study which will compare 300 women and men with non-specific LBP (aged 18-55 years) with 100 matched referents without a history of LBP. Participants will be recruited from the general public and local medical facilities. Data will be collected on spinal tissue (intervertebral disc composition and morphology, vertebral fat fraction and paraspinal muscle size and composition via magnetic resonance imaging [MRI]), central nervous system adaptation (pain thresholds, temporal summation of pain, brain resting state functional connectivity, structural connectivity and regional volumes via MRI), psychosocial factors (e.g. depression, anxiety) and other musculoskeletal pain symptoms. Dimensionality reduction, cluster validation and fuzzy c-means clustering methods, classification models, and relevant sensitivity analyses, will classify non-specific LBP patients into sub-groups. This project represents a first personalised diagnostic approach to non-specific LBP, with potential for widespread uptake in clinical practice. This project will provide evidence to support clinical trials assessing specific treatments approaches for potential subgroups of patients with non-specific LBP. The classification tool may lead to better patient outcomes and reduction in economic costs.

Classifying Nonspecific Low Back Pain for Better Clinical Outcomes: Current Challenges and Paths Forward.

SYNOPSIS: Low back pain classification systems are structured assessments used to guide choices of more specific treatments. Classification systems examined in randomized controlled trials have limited effects on pain intensity and disability compared to nonclassified interventions. Potential reasons for the lack of efficacy include (1) failing to assess multidimensional factors that contribute to pain, (2) relying on clinician judgement, (3) low accessibility, and (4) poor classification reliability. Overcoming these limitations is critical to deciding whether classification systems can improve clinical practice. Only once these limitations are addressed, can we feel certain about the efficacy, or lack thereof, of classification systems. This Viewpoint guides the reader through some limitations of common classification approaches and presents a path forward to open-access, reliable, and multidimensional precision medicine for managing low back pain. J Orthop Sports Phys Ther 2023;53(5):1-5. Epub: 5 April 2023. doi:10.2519/jospt.2023.11658.

Adherence to evidence-based practice across healthcare professionals in Germany: results from a cross-sectional, nationwide survey.

BACKGROUND: Adherence to evidence-based practice (EBP) is considered a key competence to improve healthcare quality. In this study, we aimed to describe the EBP adherence of healthcare professionals working in Germany and to explore barriers and facilitators regarding the implementation of EBP in clinical practice. METHODS: A nationwide online survey was performed among healthcare professionals in Germany from January to April 2018 using the German version of the Evidence-based Practice Inventory (EBPI) questionnaire for a comprehensive assessment of adherence to EBP. Univariate logistic regression analyses were performed to explore the association between demographic and professional determinants and each EBPI dimension. RESULTS: We analysed data of 889 participants, including 318 physical therapists, 154 occupational therapists, 137 midwifes and 280 participants of six other healthcare professions. Approximately 70% of the participants generally demonstrated a positive attitude towards EBP and believed that EBP was useful in clinical practice. Broadly, 80% of the respondents evaluated themselves as being able to enact EBP behaviour in clinical practice. In contrast, less than 70% preferred to use quantitative information instead of their intuition to inform their habitual clinical behaviour. Still, 20 to 30% reported that EBP did not sufficiently account for their clinical experience and differences between patients. The strongest facilitators to EBP adherence across at least three dimensions of the EBPI were the availability of ≥ 60 min for scientific literature at work (OR: 9.67; 95% CI: 5.86; 16.30), followed by a master or higher academic degree (OR: 9.09, 95% CI: 5.86; 14.28) and the involvement in ≥ 1 scientific publication (OR: 7.06, 95% CI: 5.10; 9.85). CONCLUSIONS: This study showed that healthcare professionals in Germany in general had a positive attitude towards EBP although they currently do not consider EBP principles in its entirety. The most important determinant positively influencing a healthcare professional's decision to perform EBP was the time available for scientific literature at work. German healthcare professionals experience similar barriers towards the implementation of EBP in clinical practice compared to other international healthcare settings. These barriers should be targeted by future research. TRIAL REGISTRATION: German Clinical Trials Register (DRKS00013792). Registered 19 January 2018.

Interventions for promoting evidence-based guideline-consistent surgery in low back pain: a systematic review and meta-analysis of randomised controlled trials.

PURPOSE: Examine the effectiveness of interventions to approach guideline-adherent surgical referrals for low back pain assessed via systematic review and meta-analysis. METHODS: Five databases (10 September 2021), Google Scholar, reference lists of relevant systematic reviews were searched and forward and backward citation tracking of included studies were implemented. Randomised controlled/clinical trials in adults with low back pain of interventions to optimise surgery rates or referrals to surgery or secondary referral were included. Bias was assessed using the Cochrane ROB2 tool and evidence certainty via Grading of Recommendations Assessment, Development and Evaluation (GRADE). A random effects meta-analysis with a Paule Mandel estimator plus Hartung-Knapp-Sidik-Jonkman method was used to calculate the odds ratio and 95% confidence interval, respectively. RESULTS: Of 886 records, 6 studies were included (N = 258,329) participants; cluster sizes ranged from 4 to 54. Five studies were rated as low risk of bias and one as having some concerns. Two studies reporting spine surgery referral or rates could only be pooled via combination of p values and gave evidence for a reduction (p = 0.021, Fisher's method, risk of bias: low). This did not persist with sensitivity analysis (p = 0.053). For secondary referral, meta-analysis revealed a non-significant odds ratio of 1.07 (95% CI [0.55, 2.06], I2 = 73.0%, n = 4 studies, Grading of Recommendations Assessment, Development and Evaluation [GRADE] evidence certainty: very low). CONCLUSION: Few RCTs exist for interventions to improve guideline-adherent spine surgery rates or referral. Clinician education in isolation may not be effective. Future RCTs should consider organisational and/or policy level interventions. PROSPERO REGISTRATION: CRD42020215137.

Low test-retest reliability of a protocol for assessing somatosensory cortex excitability generated from sensory nerves of the lower back.

In people with chronic low back pain (CLBP), maladaptive structural and functional changes on a cortical level have been identified. On a functional level, somatosensory cortical excitability has been shown to be reduced in chronic pain conditions, resulting in cortical disinhibition. The occurrence of structural and/or functional maladaptive cortical changes in people with CLBP could play a role in maintaining the pain. There is currently no measurement protocol for cortical excitability that employs stimulation directly to the lower back. We developed a protocol for the measurement of single pulse somatosensory evoked potential (SEP) waveforms and paired-pulse behavior (PPB) generated from sensory nerves of the lower back and quantified its test-retest reliability in a sample of 30 healthy individuals to gain insights into the normal variability of cortical responses, which could then be compared to results from people with CLBP. We investigated cortical excitability by measuring SEPs and PPB. PPB was defined as the ratio of the amplitude of the second cortical response (A2s) divided by the first cortical response (A1). A2s was determined by subtracting the response to single-pulse stimuli from the paired pulse stimuli response to account for linear superposition effects. The test-retest reliability of the protocol was very poor with no evidence of systematic bias but a high amount of random variability between sessions. There was no significant difference in the right side PPB for session 1 (Mean ratio A2s/A1 = 0.66, SD = 0.54) and session 2 (Mean ratio A2s/A1 = 0.94, SD = 1.56); mean session difference [(95% CI) = -0.44 (-1.23 to 0.34); t (22) = -1.17, p = 0.26]. The ICC3.1 (absolute agreement) for the outlier-removed right side PPB were 0.19 (95% CI: -0.84 to 0.66) and 0.43 for left side PPB (95% CI: -0.37 to 0.76). This finding potentially has wider implications for PPB protocols. If these findings were replicated in other groups and other nerves, it would question the validity of this measure more generally. However, these findings are restricted to healthy people and sensory nerves of the lower back and may not be generalizable.

[Adherence to and influencing factors of evidence-based practice in physiotherapeutic care in Germany: a cross-sectional study]. / Adhärenz und Einflussfaktoren evidenzbasierter Praxis in der physiotherapeutischen Versorgung in Deutschland ­ eine Querschnittstudie.

BACKGROUND: The implementation of evidence-based practice (EBP) is a central goal in health care. As in other areas, the transfer of scientific knowledge into clinical practice is very delayed or incomplete in physiotherapy. The primary aim of the present study is to describe the adherence to EBP among physiotherapists working in Germany. The secondary goal is the exploratory analysis of selected factors influencing the implementation of EBP. METHODS: The present exploratory analysis is based on the data of physiotherapists who participated in a cross-sectional study on the use of EBP by health care professionals (study registration no.: DRKS00013792). The participants in the online survey completed the "Evidence-based Practice Inventory", a questionnaire with five dimensions used to quantify the adherence to EBP. Univariable and multivariable regression analysis was used to examine the associations between various sociodemographic characteristics and EBP. RESULTS: 318 physiotherapists participated in the survey (age: 37±12 years; 60 % female; professional experience: 14±11 years). Approximately 70-80 % of the participants, in principle, had a positive attitude towards EBP and perceived EBP as helpful and useful in clinical practice. About 60 % of the respondents felt able to apply the principles of the EBP (e. g., acquisition, appraisal and application of external evidence). However, the data also showed that the implementation of EBP in clinical physiotherapeutic care is insufficient. For example, only 20 % of the respondents reported that their facility paid great attention to applying the principles of the EBP in decision-making, and only about a third of the respondents said that they frequently searched for or used external evidence. The strongest facilitators of EBP include the participation in scientific publications and more than one hour per week to read scientific literature at work. CONCLUSION: In principle, physiotherapists in Germany have a positive attitude towards EBP, but currently do not adequately take into account the principles of EBP. These factors should be further analyzed and targeted through effective interventions.

Validation and investigation of cross cultural equivalence of the Fremantle back awareness questionnaire - German version (FreBAQ-G).

BACKGROUND: Disrupted self-perception of the low back might contribute to chronic non-specific low back pain. The Fremantle back awareness questionnaire is a simple questionnaire to assess back specific self-perception. The questionnaire has recently been translated to German (FreBAQ-G). The aim was to further investigate the psychometric properties of the FreBAQ-G, to evaluate its cross cultural validity in patients with chronic non-specific LBP and to explore potential relationships between body perception, pain, disability and back pain beliefs. METHODS: In this cross-sectional multicentre study, sample data were merged with data from the validation sample of the original English version to examine cross-cultural validity. Item Response Theory was used to explore psychometric properties and differential item function (DIF) to evaluate cross-cultural validity and item invariance. Correlations and multiple linear regression analyses were used to explore the relationship between altered back specific self- perception and back pain parameters. RESULTS: Two hundred seventy-two people with chronic low back pain completed the questionnaires. The FreBAQ-G showed good internal consistency (Cronbach's alpha = 0.84), good overall reliability (r = 0.84) and weak to moderate scalability (Loevinger Hj between 0.34 and 0.48). The questionnaire showed unidimensional properties with factor loadings between 0.57 and 0.80 and at least moderate correlations (r > 0.35) with pain intensity, pain related disability and fear avoidance beliefs (FABQ total - and subscores). Item and test properties of the FreBAQ-G are given. Only item 7 showed uniform DIF indicating acceptable cross-cultural validity. CONCLUSIONS: Our results indicate that the FreBAQ-G is a suitable questionnaire to measure back specific self-perception, and has comparable properties to the English-language version.

Effects of a movement control and tactile acuity training in patients with nonspecific chronic low back pain and control impairment - a randomised controlled pilot study.

BACKGROUND: Nonspecific chronic low back pain (NSCLBP) is a heterogeneous condition that is associated with complex neuromuscular adaptations. Exercise is a widely administered treatment, but its effects are small to moderate. Tailoring patient-specific exercise treatments based on subgroup classification may improve patient outcomes. OBJECTIVE: In this randomised controlled pilot study, our objective was to compare the feasibility and possible effects of a specific sensorimotor treatment (SMT) with those of a general exercise (GE) programme on patients with NSCLBP and control impairment (CI). METHODS: Patients with NSCLBP and CI were randomised into an SMT or a GE programme spanning 6 sessions each. The feasibility criteria included the study design, assessments, interventions and magnitudes of effects, and costs. Adverse events were documented. Primary (pain, physical function, and quality of life) and secondary outcomes were assessed three times: twice at baseline (t1a and t1b) to estimate parameter stability and once after the intervention (t2). RESULTS: Two-hundred and twenty-seven patients were screened to include 34 participants with NSCLBP and CI. Both treatment programmes and the assessments seemed feasible because their durations and contents were perceived as adequate. The total cost per participant was €321. Two adverse events occurred (one not likely related to the SMT, one likely related to the GE intervention). The SMT showed a tendency for superior effects in terms of pain severity (SMT t1a 3.5, t2 1.1; GE t1a 3.0, t2 2.0), pain interference (SMT t1a 1.9, t2 0.4; GE t1a 1.5, t2 0.9), physical component of quality of life (SMT t1a 39, t2 46; GE t1a 45, t2 48), and movement control. CONCLUSIONS: The SMT approach proposed in this study is feasible and should be tested thoroughly in future studies, possibly as an addition to GE. To ensure the detection of differences in pain severity between SMT and GE in patients with NSCLBP with 80% power, future studies should include 110 patients. If the current results are confirmed, SMT should be considered in interventions for patients with NSCLBP and CI. TRIAL REGISTRATION: Registered in the German Register for Clinical Trials (Trial registration date: November 11, 2016; Trial registration number: DRKS00011063 ; URL of trial registry record); retrospectively registered.

Cross-cultural adaptation, internal consistency, test-retest reliability and feasibility of the German version of the evidence-based practice inventory.

BACKGROUND: A psychometrically robust measurement instrument is prerequisite to tailor and monitor interventions aiming to improve evidence-based practice (EBP). The recently developed "Evidence-based Practice Inventory" (EBPI) questionnaire (five dimensions) provides a sound inventory for a comprehensive assessment of adherence to EBP, and identification of barriers and facilitators for EBP. The aims of this study were to establish a German language version of the EBPI and to examine the instrument's reliability in a diverse sample of healthcare professionals. METHODS: The English version of the EBPI was translated, adopted and subsequently test-retest reliability of the German language EBPI was examined in a nationwide online survey. Participants working in Germany were invited to complete the questionnaire twice. For each EBPI dimension, internal consistency reliability (Cronbach's alpha) and the relative test-retest reliability (intraclass correlation coefficient, ICC) were calculated. The standard error of measurement, limits of agreement and minimal detectable change values were estimated to quantify measurement error. RESULTS: A German language version of the EBPI was established. In the online survey, the EBPI was initially completed by 889 healthcare professionals. At follow-up, 344 individuals (39%) completed the questionnaire (74% female; mean work experience: 13.6 years). The ICCs for the five dimensions varied between 0.78 and 0.86. The standard error of measurement varied between 6.5 and 8.8% of the respective dimension scale range, and the limits of agreement between 24 and 37%. For internal consistency reliability, alpha varied between 0.64 and 0.90. There were neither floor nor ceiling effects, nor any other relevant feasibility issues. CONCLUSIONS: The German language EBPI can be used to assess EBP adherence of healthcare professionals in clinical practice, and to identify barriers and facilitators for an EBP conform behaviour. Results on test-retest reliability indicate that the EBPI produces reliable scores when used for group comparisons, but the questionnaire seems insufficiently reliable for individual measurements over time. Methods of item response theory or Rasch measurement theory should be used for further evaluation and revision of the EBPI, informed by the results of this study. TRIAL REGISTRATION: German Clinical Trials Register ( DRKS00013792 ). Registered 19 January 2018.

The translation, validity and reliability of the German version of the Fremantle Back Awareness Questionnaire.

BACKGROUND: The Fremantle Back Awareness Questionnaire (FreBAQ) claims to assess disrupted self-perception of the back. The aim of this study was to develop a German version of the FreBAQ (FreBAQ-G) and assess its test-retest reliability, its known-groups validity and its convergent validity with another purported measure of back perception. METHODS: The FreBaQ-G was translated following international guidelines for the transcultural adaptation of questionnaires. Thirty-five patients with non-specific CLBP and 48 healthy participants were recruited. Assessor one administered the FreBAQ-G to each patient with CLBP on two separate days to quantify intra-observer reliability. Assessor two administered the FreBaQ-G to each patient on day 1. The scores were compared to those obtained by assessor one on day 1 to assess inter-observer reliability. Known-groups validity was quantified by comparing the FreBAQ-G score between patients and healthy controls. To assess convergent validity, patient's FreBAQ-G scores were correlated to their two-point discrimination (TPD) scores. RESULTS: Intra- and Inter-observer reliability were both moderate with ICC3.1 = 0.88 (95%CI: 0.77 to 0.94) and 0.89 (95%CI: 0.79 to 0.94), respectively. Intra- and inter-observer limits of agreement (LoA) were 6.2 (95%CI: 5.0-8.1) and 6.0 (4.8-7.8), respectively. The adjusted mean difference between patients and controls was 5.4 (95%CI: 3.0 to 7.8, p<0.01). Patient's FreBAQ-G scores were not associated with TPD thresholds (Pearson's r = -0.05, p = 0.79). CONCLUSIONS: The FreBAQ-G demonstrated a degree of reliability and known-groups validity. Interpretation of patient level data should be performed with caution because the LoA were substantial. It did not demonstrate convergent validity against TPD. Floor effects of some items of the FreBAQ-G may have influenced the validity and reliability results. The clinimetric properties of the FreBAQ-G require further investigation as a simple measure of disrupted self-perception of the back before firm recommendations on its use can be made.

A systematic review and meta-analysis of the reliability and validity of sensorimotor measurement instruments in people with chronic low back pain.

BACKGROUND: Deficits in the sensorimotor system and its peripheral and central processing of the affected body part might be a contributing factor to chronic low back pain (CLBP). Hence, sensorimotor assessment is important. Valid and reliable sensorimotor measurement instruments are needed. OBJECTIVE: To investigate the reliability and validity of sensorimotor measurement instruments for people with chronic low back pain (CLBP). DESIGN: Systematic review and meta-analysis. METHODS: The review was undertaken using the COSMIN guidelines. Databases were searched for studies investigating the clinimetric properties of sensorimotor tests in people with CLBP. The methodological study quality was rated by two independent reviewers using the COSMIN 4-point rating checklist. RESULTS: Ten studies were included covering six sensorimotor measurement instruments with findings for reliability/measurement error, known-groups validity and convergent validity. The methodological quality ranged from poor to good, with only one study rated as good. There was insufficient evidence of enough quality to assess reliability/measurement error or convergent validity. Two-point discrimination, laterality judgement and movement control tests had moderate evidence supporting their ability to distinguish between healthy people and those with CLBP. CONCLUSIONS: Two-point discrimination, laterality judgment and movement control tests demonstrate the greatest level of known-groups validity for people with CLBP. However, as the reliability of these measurement tools has yet to be established, this validity data should be interpreted cautiously. Further research is warranted to investigate the clinimetric properties of these sensorimotor techniques.