In this research project, the researchers will implement the Start-MSK tool, which is a screening instrument to support and facilitate the work of directing the right treatment to the right patient with musculoskeletal pain to promote recovery and improve health outcomes. The screening tool aims to identify prognostic factors to stratify patients into groups with different risks for long-term pain and disability. A total of 300 patients, 18 years and older, with musculoskeletal pain who seek primary care rehabilitation and a physiotherapist will be recruited. For this project, the investigaters are in contact with 10-15 primary care units in the Stockholm, Västra Götaland, Uppsala and Skåne Regions. Patients who are recruited will receive care from a physiotherapist and with a follow-up for 6 months. The primary aim is to investigate whether Start-MSK can predict the outcome (pain, quality of life) of the treatment at 3 months, and at long-term follow-up 6 months. The investigators will also conduct interview studies using focus groups with the physiotherapists and individual interviews with included patients who are part of the study to capture their experiences of using the Start-MSK; about how the participants feel the use has affected treatment and the measures they have received. Through Start-MSK, which is a step towards precision-based treatment for musculoskeletal pain, some of the long-term pain should be preventable.

PROJECT PLAN AIM The overall aim is to strengthen the patient-centred care for people with musculoskeletal pain disorders seeking primary health care by supporting shared decision-making about treatment by investigating how a stratifying tool - the Start-Musculoskeletal - can be implemented in primary care thus enhancing precision-based primary care.

BACKGROUND Musculoskeletal (MSK) disorders are some of the most prevalent and disabling chronic pain conditions globally. The prevalence of MSK pain is high (25%-32%) and recurrences are common. Musculoskeletal disorders have a major impact on the individual, health care, and society and thus are one of the most common causes of seeking primary care.

Start-MSK is a short easy-to-use tool to stratify/classify the patient to risk for developing long-term pain. The use of Start-MSK works in two steps: first, it classifies/stratifies the patient to a low, medium/high risk of long-term pain through 10 questions on pain, functional level, and psycho-social factors (yellow flags). Second, the outcome of the tool supports the caregiver in a shared decision process to decide on an optimal level of care/management divided into: low (information/information about level of exercises); moderate (supervised exercises/management on some occasions); high risk (multimodal treatment where psychological factors are taken into consideration). The Start MSK is cross-culturally translated and validated in a Swedish primary care context. For the tool to be implemented in Swedish primary health care it needs to be further investigated in a mixed method design study including two parts: one investigating the internal and predictive validity of the tool and a second investigating how caregivers and patients experience the use of such a stratification tool. The doctoral project provides a validated prognostic tool for shared decision-making for best practice care, to be used in primary health care with established cutoff points to stratify patients with the most common MSK pain disorders into low-, medium-, and high-risk subgroups. The qualitative analysis of patient and healthcare perspectives will inform caregivers on how to embed the tool into clinical practice.

Research questions:

1. To stratify/classify patients with MSK pain disorders seeking primary care into low, medium and high risk using the tool Start MSK and to describe the risk groups regarding demographic data, pain and health-related quality of life (HRQoL) and to investigate if the tool can discriminate between the risk groups regarding these factors.
2. To investigate the predictive validity of the MSK Start tool, by following the risk groups longitudinally to investigate how the risk groups are associated with the outcome of pain and HRQoL at 3 and 6 months and to investigate whether the implemented treatment matches the stratification to the risk groups.
3. To investigate how physiotherapists experience the use of MSK Start to stratify patients to treatment level, thus how Start MSK supports shared decision-making.
4. To investigate how patients seeking primary health care experience the use of MSK-Start in the process of shared decision-making of treatment.

METHODS Patients (n=300), 18-70 years, with one of five MSK pain (back-, neck-, hip-, shoulder and multi-pain) conditions seeking ten primary health care units will be invited to participate in the study and if eligible will be consecutively included. Up to 10 primary healthcare units (PHC) will be invited to participate in the project (ca 40 patients/unit). For this project, the investigators will reach out to 10-15 PHC units in Region Stockholm and other regions. Data will be collected via a web-based survey. Data collection started April 2025 and is ongoing. Exclusion criteria are malignant and inflammatory disorders and not being able to understand the Swedish language orally and in writing.

At baseline and at 3 months, a questionnaire will be sent via a web-based system including questions on demographic data and The Start-MSK (10), EQ-5-D for HRQoL, and Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ), data on pain intensity, sleep quality and physical activity level and at 3 months a question on global recovery. The data will be used in studies 1 and 2 of the projects' studies while a qualitative data collection will be performed amongst patients and physiotherapists at the primary health care units at three months follow-up. Data on what kind of MSK disorder, the number of treatments and treatment are reported by the physiotherapists 8 weeks following baseline.

Instruments

• Start-MSK is a self-report tool comprising 10 questions that measure different constructs of functional and psychosocial pain-related factors to predict persistent disabling pain. The first question is about the severity of pain, and the score of this question is determined by a number 0-10, with 10 representing the worst pain. Questions 2-10 are dichotomously answered by, yes or no. A total score of 0 and 12 is obtained where 12 represents the worst. The patient is stratified based on the total score to a subgroup with low (0-4), medium (5-8), or high (9-12) risk of persistent disabling pain, respectively.
• The modified Örebro Musculoskeletal Pain Questionnaire (ÖMPSQ) includes 10 questions, comprising the duration of the pain period and questions related to psycho-social risk factors in musculoskeletal pain; self-perceived function, pain experience, fear-avoidance beliefs, distress and return to work expectancy. The questions are scored, on a scale from 0-10, 10 being worst. A cutoff of ≥50 has been suggested to indicate a higher-risk group. The Swedish version of the short version ÖMPSQ has been validated for non-acute musculoskeletal pain.
• The EQ-5D-5L measures the quality of life and comprises five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression and is scored from 1 (worst imaginable health) to 5 (best imaginable health). The scores are transformed into an index value ranging from -0.59 to 1 indicating perfect health.

Power To gather data for studies 1 and 2 and to investigate the discriminate validity (also called known-group validity), a minimum of 100 patients per subgroup is recommended. Similar validation studies on the Start-MSK tool reported that approximately 10% (range, 7.5-15.0%) of the total sample was stratified into the risk group with the fewest participants, most often the high-risk group. Considering these figures, the aim is a sample size of 300-400 participants in the current project.

Methods specific studies

Study I: I: The risk groups will be described using the cut-off baseline values from the Start-MSK tools, for low (0-4 points) medium (5-8), and high risk (9-12). Hypotheses are tested on patients who are stratified in medium or high-risk groups who have higher pain, and lower levels of HRQoL compared to low risk using baseline data. Evaluation will be based on analysis of variance and the Chi2 test for trends for comparing and testing associations in categorical outcome measures. The cross-sectional construct validity will be assessed by calculating agreement (percentage agreement and Cohen's kappa, 95% CI) of StarT-MSK stratification (low risk versus. combined medium and high-risk subgroups) versus the two ÖMSPQ risk categories at baseline using the cut point of <50/>50.

Study II: To study if the stratification of patients to the three risk groups can predict pain and HRQoL at 3 months, linear and logistic regression models will be used. The hypothesis is that the outcome of pain and HRQoL at 3 months will associate to the stratification of the risk group. A successful outcome will be predefined according to the literature. Results will be presented as odds ratios (OR), with 95% confidence intervals (95% CI). Confounding factors such as age, pain site, and sex will be controlled for. Responsiveness (sensitivity to change) will be calculated by Area Under the Curve (AUC) for discriminating any improvement, from no change on the global change question at 3-month follow-up.

Study III-IV: To explore patients' and physiotherapists' perspectives about stratified primary care based on prognosis and as a support for shared decision-making. Data will be collected by focus groups. Relevant stakeholders such as patients from the different stratified risk groups and physiotherapists will be invited to either individual interviews or to focus groups. Two researchers will hold the focus group discussion. Fifteen individual interviews with patients (study III) and 4-5 focus groups with physiotherapists (study IV) with 3-5 participants in each group are planned to achieve rich data to fulfil the study aims. Data from the interviews will be transcribed, coded, and analyzed according to qualitative content analysis. The semi-structured questions posed will be around patients' and clinicians' experienced barriers and facilitators to embed the short instrument - Start MSK - into clinical practice.

Inclusion Criteria:

• adults with musculoskeletal pain (neck, back, shoulder, hip, knee, multisite pain)
• recruited from primary care, aged 18 and above

Exclusion Criteria:

• malignant and inflammatory diseases
• inability to understand spoken and written Swedish

All

People, more than 18 years, with musculoskeletal pain seeking physiotherapist in primary care.