Low back pain is the leading cause of disability worldwide and one of the main reasons for consulting in primary care. This project aims to improve the management of people with low back pain in primary care through an innovative intervention developed in collaboration with general practitioners, physiotherapists, and occupational therapists.

The main objective is to test the effectiveness of a multilevel intervention designed to improve the care pathway for individuals with low back pain consulting their general practitioner. The intervention supports healthcare professionals in adopting practices based on current guidelines, promotes patient education, and offers an interprofessional care pathway tailored to each person's needs and profile.

The study will include over 100 general practitioners in French-speaking Switzerland, randomly assigned to either the intervention group or the control group (usual care). Around 500 patients will be followed according to their doctor's approach. Their progress will be monitored over 12 months using questionnaires and administrative data.

This project addresses an urgent need to improve the care pathway in primary care. It will rigorously assess the effectiveness of this new care approach and explore the barriers and facilitators to its integration into daily practice, taking into account the experiences of both healthcare professionals and the people concerned.

Using an effectiveness-implementation hybrid type I design, this study aims to test the effectiveness of a multilevel intervention in primary care for patients with LBP and investigate the implementation processes.

The primary objectives are to test the effectiveness of a multilevel intervention in primary care for patients with low back pain (PRIME: PRImary care MultilEvel intervention for low back pain) compared with usual care in terms of: (1.1) Cost-effectiveness (system-level) (1.2) Imaging prescription rate (practitioner-level); (1.3) Self-reported back-related disability (patient-level).

Secondary objectives are:

2.1 To evaluate the effectiveness of the PRIME intervention on opioid prescription rate and sick leave days prescription by general practitioners (practitioner-level) 2.2 To evaluate the effectiveness of the PRIME intervention on pain intensity, work participation, health-related quality of life, global perceived change, Pain Self-Efficacy, Fear Avoidance Beliefs, and beliefs about LBP (patient-level) 2.3 To evaluate the effectiveness of the training on clinicians' beliefs about LBP and confidence in treating patients with LBP (practitioner-level)

As an effectiveness-implementation hybrid design type 1 study, implementation process outcomes are secondary objectives. These include: (3.1) evaluating the acceptability, appropriateness, feasibility, fidelity and adoption of the multilevel intervention among general practitioners, physiotherapists and occupational therapists; (3.2) exploring barriers and facilitators to the implementation of the multilevel intervention among healthcare practitioners; (3.3) exploring the experience of a biopsychosocial 2-day experiential workshop among trained physiotherapists; (3.4) exploring the experience and acceptability of the multilevel intervention among patients.

The study is a cluster randomized controlled trial, with the unit of randomization being quality circles of general practitioners affiliated with a care network in the French-speaking part of Switzerland. A total of 20 quality circles will be randomized into intervention and control arms. Each quality circle includes multiple general practitioner practices, and approximately 100 general practitioners will participate in total.

General practitioners in the intervention group will receive a multilevel intervention including: general practitioners training, reminders, tools for patients education and a dedicated clinical pathway. The clinical pathway includes a gradual stratified care pathway based on risk factors for chronicity. The core interventions of this 3-step clinical pathway are education and self-management, individual sessions with a trained physiotherapist, and multidisciplinary group management. Physiotherapists providing individual sessions in the intervention group will all have participated in a two-day workshop to improve their knowledge of good clinical practice and develop their competence to manage risk factors of chronicity within a biopsychosocial framework. They will be trained to address unhelpful beliefs and avoidance behaviors through good communication and gradual exposure exercises, as improving unhelpful beliefs and reducing kinesiophobia are important mediators of successful rehabilitation. If general practitioners recommend multidisciplinary group management, patients will receive a comprehensive assessment of risk factors and tailored education by an experienced occupational therapist. If this confirms the need for multidisciplinary group management, patients will receive a structured outpatient multidisciplinary group rehabilitation for LBP that specifically targets physical and psychological factors.

The clinical pathway provides advice to general practitioners at three stages:

In the first consultation, general practitioners will screen for red flags, reassure and explain LBP to patients with the above-mentioned resources, and prescribe medication if needed. They will also decide whether the patient needs to immediately start physiotherapy sessions with a trained physiotherapist.

Ten days after the first consultation, patients will receive an SMS/email directing them to an online questionnaire that assesses risk factors of chronicity (Start Back Tool) and their ability to work. General practitioners will automatically receive via email a summary of the risk of chronicity (low, medium or high) and the patient ability to work. The email will only communicate the current state of the patient and the general practitioner is free to decide whether to follow the clinical pathway recommendation, as independence of practice is also important for implementation. If the patient has already been prescribed trained physiotherapy, it is suggested that nothing is changed at that time (10 days), independent of the level of risk. Coordination of care with the physiotherapist is strongly advised in this case. In case physiotherapy has not yet been prescribed, general practitioners are advised the following:

(i) If the patient is able to work normally and has a low risk of chronicity, he or she should continue to self-manage and the general practitioner should decide to organize a follow-up meeting based on the patient needs; (ii) If the patient has a medium or high risk of chronicity, or is still not able to work normally because of LBP, the general practitioner is advised to prescribe 6 sessions of trained physiotherapy (with the possibility to prescribe additional sessions in the future).

At 6 weeks after the first consultation, patients will receive another SMS/email with the same questionnaire to fill out, and general practitioners will receive the automated email again. At 6 weeks, general practitioners will be advised the following:

(i) If the patient is able to work normally and has a low risk of chronicity, it is probable that the patient has recovered. Therefore, no new treatment should be started and physical activity should be promoted. A follow-up consultation can be organized if needed.

(ii) If the patient is able to work normally and has a medium risk of chronicity, prescription of trained physiotherapy would be advised for 6 sessions if not yet started. If physiotherapy was already started and the patient is improving, 6 additional sessions could be offered at this stage based on patient and physiotherapist reports; (iii) If the patient is not able to work normally or has high risk of chronicity, general practitioners would be advised to offer a comprehensive assessment of risk factors and tailored education by a specialized occupational therapist. If this confirms the need for multidisciplinary treatment, multidisciplinary management could be started.

Importantly, for patients that have already started physiotherapy, physiotherapists and general practitioners are advised to work together to coordinate care, as interprofessional collaboration was highlighted to be a critical point in the pilot study.

The primary effectiveness outcomes include patient-reported back-related disability (measured by the Roland-Morris Disability Questionnaire), the proportion of patients referred for spinal imaging within three months, and the incremental cost per quality-adjusted life year (QALY) gained. Secondary patient outcomes include pain intensity, health-related quality of life, work participation, pain self-efficacy, fear avoidance beliefs, general beliefs about LBP, and global perceived improvement. Practitioner-level outcomes include opioid and sick leave prescription rates, as well as changes in GP confidence and beliefs about LBP.

General practitioners in the control group will have no specific training or intervention and will treat patients according to their usual practice.

Implementation outcomes are evaluated using both quantitative and qualitative methods. These include the acceptability, appropriateness, feasibility, adoption, and fidelity of the intervention among general practitioners, physiotherapists, and occupational therapists. The experience of the physiotherapists who complete a two-day biopsychosocial training workshop is also explored. Patient perspectives on the acceptability of the intervention will be collected through interviews or focus groups.

Patients data collection will occur at baseline and at 10 days, 6 weeks, 3, 6, 9, and 12 months. Patients complete questionnaires online via REDCap at each time point. Administrative data and prescribing behavior are also collected to complement self-reported outcomes. General practitioners will complete questionnaires before and after training and at the end of the recruitment period. Focus groups and interviews with healthcare professionals and patients will be recorded, anonymized, transcribed, and analyzed using thematic analysis.

The target sample size is at least 500 patients, with approximately 25 per cluster. Recruitment may exceed this number to ensure that a minimum of 200 patients per group complete the 6-month follow-up. The study has been powered to detect a minimal clinically important difference of 2.5 points on the Roland-Morris scale, assuming a standard deviation of 6 and an intracluster correlation coefficient (ICC) of 0.05. Analyses will be conducted according to the intention-to-treat principle, using linear and generalized linear mixed models to account for clustering. Cost-effectiveness will be assessed from both the healthcare payer and societal perspectives using the EQ-5D-5L.

Inclusion Criteria:

• Patients consulting their participating general practitioner for a primary concern of LBP (with or without leg pain)
• Above 18 years old

Exclusion Criteria:

• If they had consulted their general practitioner for a primary concern of LBP in the past 3 months, as care was already started prior to the study.
• Unable to give consent (eg. cognitive impairment)
• Unable to access comfortably an electronic device to answer the questionnaires (smartphone, computer)
• Unable to answer questionnaires in French
• Known pregnancy
• Have had back surgery in the last 6 months
• Any specific cause of LBP (e.g. inflammatory arthritis, malignancy, infection, fracture, cauda equina syndrome).
• a major strength deficit (M3 and below) due to radiculopathy or have to be referred directly to emergency or a specialist because of that. As specific causes of LBP may be unknown at the first consultation in primary care, patients with a confirmed diagnosis of specific LBP could be excluded post-allocation by an independent doctor that is part of the Data Monitoring Committee.

All data that can be shared (informed consent, ethical aspects) will be shared. These data will be made public at the end of project on the Swiss-based data management portal OLOS. The data set will be assigned a globally unique and persistent identifier (PID) to make it easily findable.

The data set will be thoroughly described, including description of the metadata, the protocol and procedures to collect the data, the license of the data and how it can be (re)used. The documents describing the data set and data will always have the PID of the data set and will be fully accessible.

After the study completion

All outcome measures will be directly recorded in Redcap by the participants (no outcome assessor).