Health And Performance Promotion in Youth (HAPPY) hybrid effectiveness-implementation cluster randomised trial: comparison of two strategies to implement an injury prevention exercise programme in Danish youth handball.

OBJECTIVE: To investigate if a combination of an online and onsite implementation strategy was superior to an online-only strategy in enhancing the use of an injury prevention exercise programme (IPEP) and in reducing the risk of shoulder, knee and ankle injuries in youth community handball players (age 11-17) over a handball season. METHODS: In this 30-week hybrid effectiveness-implementation cluster randomised type 3 study, 20 youth handball clubs were randomly assigned 1:1 to either a combined online and onsite implementation strategy (coach workshop using the health action process approach behaviour change model and health service provider (HSP) support) or an online-only strategy (control group). The primary implementation outcome was coach-reported adherence, measured as the average IPEP exercise usage by the team over 30 weeks. The primary effectiveness outcome was player-reported handball playing time to any new handball-related shoulder, knee and ankle injuries, reported weekly using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. RESULTS: We enrolled 63 coaches (27% women) and 945 players (mean age 14.5 years, 55% girls). Intention-to-treat analyses showed no statistically significant difference between implementation strategies in adherence (between-group difference 1.4, 95% CI -0.5 to 3.4) or in cumulative injury risk (between-group difference 5.5% points, 95% CI -2.2 to 13.1). CONCLUSION: Our findings demonstrate that in youth community handball, a combined online and onsite implementation strategy, including a coach workshop and HSP support, was not superior to an online-only strategy regarding adherence to an IPEP or in reducing shoulder, knee and ankle injury risk. TRIAL REGISTRATION NUMBER: NCT05294237.

Characteristics and outcomes of patients with low back pain with and without radiating leg pain following the GLA:D back program.

BACKGROUND: Some patients with low back pain (LBP) also report radiating leg pain which is a prognostic factor for poorer clinical outcomes. We aimed: 1) to compare the baseline characteristics of patients with LBP with - (LBP + leg pain) and without radiating leg pain (LBP - alone); 2) to investigate whether patients with LBP + leg pain show similar post-treatment outcomes as compared to LBP - alone, after participation in an exercise and patient education program, i.e. the GLA:D Back program. METHODS: The patient sample included 3508 patients in the GLA:D Back program between March 2018 and August 2022. The outcomes were mean changes in LBP intensity, back-related activity limitation, self-efficacy and fear of movement measured from baseline to 3, 6 and 12 months. Baseline characteristics were compared with descriptive statistics, and linear mixed models were used to estimate group differences in changes from baseline to 3-, 6- and 12 months. RESULTS: 1915 (55%) of the patients were in the group LBP- alone and 1593 (45%) in the LBP + leg pain. The LBP + leg pain group displayed higher STarT back classification (greater risk of chronicity) compared to the LBP-alone. The LBP + leg pain group showed almost similar improvements in all outcomes compared to LBP - alone after the GLA:D Back program. CONCLUSION: In long-lasting (chronic) LBP patients, the LBP + leg pain group improved to the same extent as LBP - alone regarding LBP intensity, disability, and fear of movement following an exercise and patient education program, GLA:D Back.

Usual care for low back pain and barriers to best practice: A cross-sectional study in Danish general practice.

OBJECTIVES: To describe the current content of low back pain (LBP) care in Danish general practice, the patients' self-management activities, and the clinicians' experienced barriers to providing best practice care. METHODS: This cross-sectional observational study included adults with LBP seeking care in Danish general practice from August 2022 to June 2023. Patient-reported information included demographics, pain intensity, medical history, treatments, and self-management strategies. Clinicians provided data specific to each consultation, detailing the content of these consultations, and barriers to best practice in the specific cases. RESULTS: The study involved 71 clinicians from 42 general practice clinics, with patient-reported data from 294 patients, and clinician-reported data from 283 (95%) consultations. The mean age for the included patients was 53 years, 56% were female, and 31% had been on sick leave for LBP during the previous 3 months. Moreover, 44% had seen two or more healthcare professionals in the previous month, 55% had previously undergone diagnostic imaging for LBP, 81% reported using any type of analgesics, and 14% reported using opioids. The majority (91%) reported engaging in self-management activities to alleviate pain. Consultations typically included a physical examination (84%), information about the cause of the pain (74%), and management advice (68%), as reported by clinicians or patients. In general, clinicians reported consultation elements more frequently than patients. Clinicians reported providing best practice care in 84% of cases, with time constraints (23%) and patient expectations (10%) being the most common barriers. CONCLUSIONS: This study provides detailed insights into the management of LBP in Danish general practice. It reveals a complex landscape of patient engagement, varying management strategies, and differing perceptions of care content between patients and clinicians. Patients were often engaged in self-management activities and clinicians reported few barriers to providing best practice care.

Pain trajectories over 12 months following conservative care consultation in patients with lumbar spinal stenosis.

OBJECTIVE: To investigate symptom trajectories in chiropractic patients with lumbar spinal stenosis (LSS). METHODS: Patients diagnosed with LSS were recruited from chiropractic clinics and self-reported questionnaires were collected at baseline and 1-year follow-up. Patients received weekly text messages about low back pain (LBP) and leg symptoms for 1 year. Group-based trajectory modelling was performed to identify symptom trajectory groups. The groups were compared based on patient characteristics, LBP and leg pain intensity, Oswestry Disability Index (ODI) and Zurich Claudication Questionnaire (ZCQ). RESULTS: A total of 90 patients were included in the analysis. A three-group trajectory model was chosen: 'improving' (16%), 'fluctuating/improving' (30%), and 'persistent' (54%). The 'persistent' group had a higher proportion of women [71% (95% CI 57-82%)] than the 'improving' group 29% (95% CI 11-56%), and a higher ODI score at both baseline [34.2 (95% CI 29.7-38.8) vs. 22.8 (16.4-29.1)] and 1-year follow-up [28.1 (95% CI 23.2-33.0) vs. 4.8 (0.1-9.4)]. Similar differences were observed for ZCQ symptom and function scores. CONCLUSIONS: Pain symptoms in people with LSS followed distinctly different trajectories. Half of the sample had a pattern of consistently severe symptoms over a year, while the other half either improved rapidly or experienced fluctuating symptoms with some improvement.

Prospective Back Pain Trajectories or Retrospective Recall-Which Tells Us Most About the Patient?

In patients with low back pain (LBP), a visually identified retrospective pain trajectory often mismatches with a trajectory derived from prospective repeated measures. To gain insight into the clinical relevance of the 2 trajectory types, we investigated which showed a higher association with clinical outcomes. Participants were 724 adults seeking care for LBP in Danish chiropractic primary care. They answered weekly short-message-services on pain intensity and frequency over 52 weeks, which we translated into 8 trajectory classes. After 52 weeks, participants selected a retrospective visual pain trajectory from the same 8 trajectory classes. Clinical outcomes included disability, back/leg pain intensity, back beliefs, and work ability. The patient-selected pain trajectory classes were more strongly associated with clinical outcomes than the short-message-service trajectory classes at baseline, at follow-up, and with outcome changes between baseline and follow-up. This held across all 5 clinical outcomes, with the strongest associations observed at week 52 and the weakest at baseline. Patients' retrospective assessment of their LBP is more strongly associated with their clinical status than their prospective assessments translated into trajectory classes. This suggests that retrospective assessments of pain trajectories may provide valuable information not captured by prospective assessments. Researchers collecting prospective pain data should know that the captured pain trajectories are not strongly reflected in patients' perceptions of clinical status. Patients' retrospective assessments seem to offer an interpretation of their pain course that is likely more clinically relevant in understanding the perceived impact of their condition than trajectories based on repeated measures. PERSPECTIVE: Prospective pain data inadequately reflect patients' clinical status. Retrospective assessments provide a more clinically valuable understanding of the impact of their condition.

What Gets Measured Gets Managed: A Scoping Review of Musculoskeletal Research Conducted Within Practice-Based Research Networks.

ABSTRACT: Musculoskeletal conditions are often managed in primary care settings. To facilitate research and healthcare quality, practice-based research networks offer sustained collaborations between clinicians and researchers. A scoping review was conducted to describe characteristics of practice-based research networks used for musculoskeletal research and musculoskeletal research conducted through practice-based research networks. Practice-based research networks were identified from 1) musculoskeletal-studies identified in OVID Medline, CINAHL, and Embase databases from inception to 5 February 2023 and in ClinicalTrials.gov and 2) from practice-based research network registries and websites. Among active musculoskeletal-focused practice-based research networks (i.e., currently recruiting and conducting research), an assessment of practice-based research network research good practices was performed. After screening 3025 records, 85 studies from 46 unique practice-based research networks met our eligibility criteria. Common conditions studied were low back pain (28%), musculoskeletal conditions not otherwise specified (25%), and osteoarthritis (19%). Thirty-two practice-based research networks (70%) were deemed to be active. Among active musculoskeletal-focused practice-based research networks, best practice data management information was retrievable for most (53%). Because of the scarcity of publicly available information, a large proportion of practice-based research network research good practice items was not assessable. Practice-based research networks have provided an avenue to assess clinical practice and patient outcomes related to musculoskeletal conditions. Further work to increase the transparency of musculoskeletal practice-based research network research practices is warranted.

Goal setting in people with low back pain attending an education and exercise program (GLA:D Back) and the impact of demographic factors.

BACKGROUND: Individual goal setting is a fundamental element in self-management supportive interventions, serving to guide actions and enhance motivation for engagement. Despite this, little is known about the goals people with back pain have and to what extent these differ across genders, age groups and geographical location. This study aimed to elucidate this by first describing individual goals set by Danish and Canadian participants in a self-management intervention for people with back pain using the ICF framework; then, determining what proportion of these goals met criteria for being specific, measurable, acceptable, and time bound, and finally, by investigating differences between countries, sexes, and age groups. METHODS: In a cross-sectional study conducted August 2018 to June 2020, 394 Danish and 133 Canadian (Alberta Province) participants defined their individual goals of participating in a self-management programme involving patient education and supervised exercises. The goals were linked to the ICF framework. Distribution of goals was compared between countries, sexes, and age groups. RESULTS: Goals most often related to the ICF component of 'Activity and Participation'. The most prevalent goals were "Walking" (DK: 20%; CA: 15%) and "Maintaining a body position" (DK: 17%; CA: 22%). Only few goals differed between populations, age and sex. All elements of SMART goal setting were recorded for 88% of Danish and 94% of Alberta participants. CONCLUSIONS: People with low back pain attending a self-management programme established goals according to the SMART criteria and focused primarily on activity. Goals were similar across countries and showed few differences across sex and age groups. The high number of different goals points to the need for individualised person-centred care.

Swiss chiropractic cohort (Swiss ChiCo) pilot study: feasibility for a musculoskeletal cohort study conducted within a nationwide practice-based research network.

PURPOSE: Practice-based research networks are collaborations between clinicians and researchers to advance primary care research. This study aims to assess the feasibility for longitudinal data collection within a newly established chiropractic PBRN in Switzerland. METHODS: A prospective observational cohort feasibility study was performed. PBRN participating chiropractors were asked to recruit patients seeking new conservative health care for musculoskeletal pain from March 28, 2022, to September 28, 2022. Participants completed clinically oriented survey questions and patient-reported outcome measures before the initial chiropractic assessment as well as 1 h, 2 weeks, 6 weeks, and 12 weeks thereafter. Feasibility was assessed through a variety of process, resource, and management metrics. Patient clinical outcomes were also assessed. RESULTS: A total of 76 clinicians from 35 unique primary care chiropractic clinics across Switzerland participated. A total of 1431 patients were invited to participate, of which 573 (mean age 47 years, 51% female) were enrolled. Patient survey response proportions were 76%, 64%, 61%, and 56%, at the 1-h, 2-, 6-, and 12-week survey follow-ups, respectively. Evidence of an association was found between increased patient age (OR = 1.03, 95%CI 1.01-1.04), patient from a German-speaking region (OR = 1.81, 95%CI 1.17-2.86), non-smokers (OR = 1.89, 95%CI 1.13-3.17), and increased pain impact score at baseline (OR = 1.18, 95%CI 1.01-1.38) and response to all surveys. CONCLUSION: The Swiss ChiCo pilot study exceeded its prespecified feasibility objectives. Nationwide longitudinal data capture was highly feasible. Similar to other practice-based cohorts, participant retention remains a challenge. Trial registration Swiss chiropractic cohort (Swiss ChiCo) pilot study (ClinicalTrials.gov identifier: NCT05116020).

What do people believe to be the cause of low back pain? A scoping review.

OBJECTIVE: To explore how causal beliefs regarding non-specific low back pain (LBP) have been quantitatively investigated. METHODS: A scoping review based on the guidelines by the JBI (former Joanna Briggs Institute) was conducted. We searched Medline, Embase, Psychinfo, and CINAHL for relevant studies and included peer-reviewed original articles that measured causal beliefs about non-specific LBP among adults and reported results separate from other belief domains. RESULTS: A total of 81 studies were included, of which 62 (77%) had cross sectional designs, 11 (14%) were cohort studies, 3 (4%) randomized controlled trials, 4 (5%) non-randomized controlled trials, and 1 (1%) case control. Only 15 studies explicitly mentioned cause, triggers, or etiology in the study aim. We identified the use of 6 questionnaires from which a measure of causal beliefs could be obtained. The most frequently used questionnaire was the Illness Perception Questionnaire which was used in 8 of the included studies. The studies covered 308 unique causal belief items which we categorized into 15 categories, the most frequently investigated being causal beliefs related to "structural injury or impairment", which was investigated in 45 (56%) of the studies. The second and third most prevalent categories were related to "lifting and bending" (26 studies [32%]) and "mental or psychological" (24 studies [30%]). CONCLUSION: There is a large variation in how causal beliefs are measured and a lack of studies designed to investigate causal beliefs, and of studies determining a longitudinal association between such beliefs and patient outcomes. This scoping review identified an evidence gap and can inspire future research in this field.

Similar improvements in patient-reported outcomes for non-specific low back pain patients with and without lumbar spinal stenosis symptoms following a structured education and exercise therapy program.

BACKGROUND: People with nonspecific low back pain (NSLBP) can also experience overlapping symptoms of lumbar spinal stenosis (LSS), but the impact on treatment outcomes is unknown. This study investigated differences in treatment outcomes for disability, back pain intensity, and leg pain intensity following an education and exercise therapy program for NSLBP patients with and without comorbid LSS symptoms. METHODS: This was a longitudinal analysis of 655 Danish participants in the GLA:D® Back program; an education and exercise therapy program for people with persistent NSLBP. Participants were classified as having comorbid LSS symptoms based on self-report. Linear mixed models were used to assess differences in change in disability (Oswestry Disability Index [0-100]) and back and leg pain intensity (Numeric Rating Scale [0-10]) at 3-, 6-, and 12-months between those with and without LSS symptoms. RESULTS: 28% of participants reported LSS symptoms. No certain differences in change in disability or back pain intensity improvement were observed at any time-point between those with and without LSS symptoms. Participants with LSS symptoms had slightly greater improvement in leg pain intensity at 6- (-0.7, 95% CI -1.2 to -0.2) and 12-months (-0.6, 95% CI -1.2 to -0.1). CONCLUSION: Compared to those without LSS symptoms, patients with persistent NSLBP and LSS symptoms can expect similar improvements in disability and back pain intensity, and slightly greater improvements in leg pain intensity with treatment. Therefore, education and exercise therapy programs designed for NSLBP are likely helpful for those also experiencing LSS symptoms.

A new paradigm for musculoskeletal pain care: moving beyond structural impairments. Conclusion of a chiropractic and manual therapies thematic series.

This commentary closes the thematic series "A new paradigm for musculoskeletal pain care: moving beyond structural impairments". The papers published in the series point to key aspects of shifting the paradigm of musculoskeletal care from clinician-led management often focused on addressing presumed structural anomalies to partnering with patients to find individual strategies that empower patients towards self-management. Several papers in the series highlighted the need for developing patient-centred models of care that respect individual patient's needs and preferences. Also, the series pointed to different options for modes of delivery including mHealth and the challenges and opportunities they present for developing person-centred strategies. For health care to provide effective support for people with musculoskeletal pain conditions, there is a need to recognise that contextual factors, including a strong patient-provider alliance, clearly play an important, perhaps primary, role. Health care professions dealing with musculoskeletal pain conditions should engage in research to investigate effective ways to move this understanding into practice including how to train providers. We hope the work collected in this series will stimulate further questions and more research as musculoskeletal pain providers seek to make their care more person-centred.

The GLA:D BACK self-management adherence and competence checklist (SMAC Checklist)-Development, content validity and feasibility.

OBJECTIVES: To unpack the complexity and impact of self-management interventions targeting musculoskeletal health conditions, we need to learn more about treatment delivery in clinical settings. Fidelity evaluation can illuminate how complex treatments are delivered and help understand the elements that lead to the effect. The objective of this study was to develop a checklist for the evaluation of the clinicians' delivery of structured patient education and exercise intervention for people with persistent back pain, the GLA:D Back intervention. The intent was to provide a checklist adaptable for the general delivery of self-management interventions for musculoskeletal pain. METHODS: We derived items for the treatment delivery fidelity checklist from behaviour change techniques and theory about communication style. We applied a three-step developmental process covering developing a preliminary fidelity intervention framework, validating checklist content and piloting and refining the checklist. RESULTS: We developed the adaptable fidelity checklist, The GLA:D BACK Self-management Adherence and Competence Checklist (SMAC Checklist). Evaluation of clinical practice using the checklist was feasible and acceptable by clinicians. Preliminary results indicate satisfactory observer agreement during pilot testing of the checklist. CONCLUSION: The GLA:D BACK Self-management Adherence and Competence Checklist is a fidelity measurement tool for the assessment of the delivery of a self-management supportive intervention for people with persistent back pain. The intention is that it can be useful as an adaptable tool for use across self-management interventions for musculoskeletal pain.

The Swiss chiropractic practice-based research network: a population-based cross-sectional study to inform future musculoskeletal research.

The Swiss chiropractic practice-based research network (PBRN) is a nationwide project developed in collaboration with patients, clinicians, and academic stakeholders to advance musculoskeletal epidemiologic research. The aim of this study was to describe the clinician population recruited and representativeness of this PBRN to inform future collaboration. A population-based cross-sectional study was performed. PBRN clinician characteristics were described and factors related to motivation (operationalised as VAS score ≥ 70) to participate in a subsequent patient cohort pilot study were assessed. Among 326 eligible chiropractors, 152 enrolled in the PBRN (47% participation). The PBRN was representative of the larger Swiss chiropractic population with regards to age, language, and geographic distribution. Of those enrolled, 39% were motivated to participate in a nested patient cohort pilot study. Motivation was associated with age 40 years or older versus 39 years or younger (OR 2.3, 95% CI 1.0-5.2), and with a moderate clinic size (OR 2.4, 95% CI 1.1-5.7) or large clinic size (OR 2.8, 95% CI 1.0-7.8) versus solo practice. The Swiss chiropractic PBRN has enrolled almost half of all Swiss chiropractors and has potential to facilitate collaborative practice-based research to improve musculoskeletal health care quality.Trial registration: Swiss chiropractic PBRN (ClinicalTrials.gov identifier: NCT05046249); Swiss chiropractic cohort (Swiss ChiCo) pilot study (ClinicalTrials.gov identifier: NCT05116020).

Characteristics associated with comorbid lumbar spinal stenosis symptoms in people with knee or hip osteoarthritis: an analysis of 9,136 good life with osteoArthritis in Denmark (GLA:D®) participants.

BACKGROUND: Previous studies have found that lumbar spinal stenosis (LSS) often co-occurs with knee or hip OA and can impact treatment response. However, it is unclear what participant characteristics may be helpful in identifying individuals with these co-occurring conditions. The aim of this cross-sectional study was to explore characteristics associated with comorbid symptoms of lumbar spinal stenosis (LSS) in people with knee or hip osteoarthritis (OA) enrolled in a primary care education and exercise program. METHODS: Sociodemographic, clinical characteristics, health status measures, and a self-report questionnaire on the presence of LSS symptoms was collected at baseline from the Good Life with osteoArthritis in Denmark primary care program for knee and hip OA. Cross-sectional associations between characteristics and the presence of comorbid LSS symptoms were assessed separately in participants with primary complaint of knee and hip OA, using domain-specific logistic models and a logistic model including all characteristics. RESULTS: A total of 6,541 participants with a primary complaint of knee OA and 2,595 participants with a primary complaint of hip OA were included, of which 40% and 50% reported comorbid LSS symptoms, respectively. LSS symptoms were associated with similar characteristics in knee and hip OA. Sick leave was the only sociodemographic variable consistently associated with LSS symptoms. For clinical characteristics, back pain, longer symptom duration and bilateral or comorbid knee or hip symptoms were also consistently associated. Health status measures were not consistently related to LSS symptoms. CONCLUSION: Comorbid LSS symptoms in people with knee or hip OA undergoing a primary care treatment program of group-based education and exercise were common and associated with a similar set of characteristics. These characteristics may help to identify people with co-occurring LSS and knee or hip OA, which can be used to help guide clinical decision-making.

Do Visual Pain Trajectories Reflect the Actual Course of Low Back Pain? A Longitudinal Cohort Study.

Different trajectories of low back pain (LBP) have been identified prospectively using repeated measures. For these trajectories to inform clinical practice, they must be available in the clinical consultation. Therefore, identified LBP trajectories have been translated into visual pain trajectories (VPTs) that allow people with LBP, at the time of consult, to reflect upon their pain experience and identify the VPT that best categorizes their pain course. We have limited knowledge regarding the extent to which a chosen VPT reflects the prospectively experienced trajectory. Thus, we explored the distribution of pain intensity and pain pattern characteristics (from prospective pain trajectory data) within the retrospectively chosen VPT classes. We enrolled patients with LBP from Danish chiropractic practice. Using SMS, participants (n = 719) scored their pain weekly on an 11-point numerical rating scale for 52 weeks. At week 52, participants identified 1 of 8 VPTs that reflected their perceived back pain trajectory during the preceding year. We found that the chosen VPTs reflected pain intensity, but that pain patterns (episodic, fluctuating, and persistent) were not systematically recognized, and the experienced course varied substantially amongst participants within the same VPT. The VPTs are related to some aspects of the experienced LBP course but are not a proxy for the SMS-measured trajectories. Reasons for apparent mismatches between the experienced course of LBP and VPT recall warrant further investigation. PERSPECTIVE: Self-reported back pain trajectories reflected pain intensities obtained through weekly SMS tracking over a year, but participants' recall did not reflect the pain patterns (episodes and fluctuations) discovered prospectively. Clinicians can use self-reported pain trajectories to facilitate a dialog about pain experience, but not as a proxy for prospective measures.

Association between physical activity, sedentary behaviour and the trajectory of low back pain.

BACKGROUND: Low back pain (LBP) is one of the world's most prevalent health issues. Patients with LBP experience various intensities and durations of symptoms, which can lead to distinctive course patterns commonly described as symptom trajectories. PURPOSE: This study aimed to investigate the association between different amounts of physical activity and sedentary behavior and the trajectory of LBP, in people with a lifetime history of LBP. STUDY DESIGN: The study involved a secondary analysis of observational longitudinal data collected from the AUstralian Twin low BACK pain (AUTBACK) study. METHODS: A total of 329 individual twins met the inclusion criteria for analysis. Latent Class Growth Analysis was used to identify distinct patterns of LBP and select the primary outcome (probability of having a severe LBP trajectory, 0%-100%). Linear regression models were used to investigate the association between different amounts of physical activity or sedentary behavior at baseline, and the probability of having a severe LBP trajectory. Results were expressed as ß coefficients and 95% confidence intervals (CI). RESULTS: Moderate-to-vigorous intensity physical activity was significantly associated with the probability of having a severe LBP trajectory (unadjusted ß -0.0276; 95%CI -0.0456 to -0.0097, p=.003). For every 1-minute increase in moderate-to-vigorous intensity physical activity per week, there was a 2.8%-point reduction in a participant's probability of having a severe LBP trajectory. No significant associations were identified between sedentary behavior or light intensity physical activity, and the probability of having a severe LBP trajectory. CONCLUSIONS: In people with a lifetime history of LBP, engagement in higher volumes of moderate to vigorous intensity physical activity at baseline was associated with a lower probability of developing a severe trajectory of LBP over 1 year.

Data-driven network analysis identified subgroup-specific low back pain pathways: a cross-sectional GLA:D Back study.

OBJECTIVES: To understand the physical, activity, pain, and psychological pathways contributing to low back pain (LBP) -related disability, and if these differ between subgroups. METHODS: Data came from the baseline observations (n = 3849) of the "GLA:D Back" intervention program for long-lasting nonspecific LBP. 15 variables comprising demographic, pain, psychological, physical, activity, and disability characteristics were measured. Clustering was used for subgrouping, Bayesian networks (BN) were used for structural learning, and structural equation model (SEM) was used for statistical inference. RESULTS: Two clinical subgroups were identified with those in subgroup 1 having worse symptoms than those in subgroup 2. Psychological factors were directly associated with disability in both subgroups. For subgroup 1, psychological factors were most strongly associated with disability (ß = 0.363). Physical factors were directly associated with disability (ß = -0.077), and indirectly via psychological factors. For subgroup 2, pain was most strongly associated with disability (ß = 0.408). Psychological factors were common predictors of physical factors (ß = 0.078), pain (ß = 0.518), activity (ß = -0.101), and disability (ß = 0.382). CONCLUSIONS: The importance of psychological factors in both subgroups suggests their importance for treatment. Differences in the interaction between physical, pain, and psychological factors and their contribution to disability in different subgroups may open the doors toward more optimal LBP treatments.