The percentage of loss time claims receiving Loss of Earnings benefits at 3 months has continued to rise amongst injured workers in Ontario despite the Workplace Safety and Insurance Board (WSIB) approach of "Better at Work". The primary health services to address loss time claims associated with musculoskeletal injuries include the evidenced-based programs of care, occupational health assessment program and musculoskeletal specialty programs, however, these are set to be revised and relaunched in Q1 2023. Across treatment protocols there are challenges that, at least in part, appear to contribute to the increasing percentage of workers on full loss of earnings at 3 months include (1) inconsistent early identification of workers who should be triaged to various health services and (2) reliable determination of the optimal timing of referral to the most targeted care to enable a safe and sustainable return to work. The investigators aim to develop and evaluate a predictive assessment model to triage workers to the best service within the first 8 weeks of their claim to increase the rate of early return to work, with the long-term goal that the triage protocol becomes part of a person-centric protocol that reduces the duration of work-related disability.

The investigators will develop and evaluate an assessment protocol for injured workers that enter any of the musculoskeletal-specific WSIB programs of care, which have been consolidated into a single program as of 2023. This study will be a prospective inception cohort design using data collected from injured workers receiving WSIB musculoskeletal programs of care services at CBI Health clinics in Ontario Canada. Worker data will be collected at intake to the program of care service and again approximately four and eight weeks after intake (or earlier if a worker completes the program of care). The investigators will complete data analysis in three steps including descriptive and bivariate associations, Maximum Likelihood-based Latent Profile Analysis, and evaluation of results against successful work outcomes and secondary outcomes. Qualitative data will be mined for alternative indicators of recovery / non-recovery. The study recruitment goal is 300 - 350 workers with complete follow-up within a 2-year period.

Background and Rationale It has long been known that early and targeted acute-stage intervention is the best way to prevent chronic pain. For 15 years the Principal Investigator has been developing novel tools, strategies, and frameworks for predicting and preventing the acute-to-chronic transition in other populations. These include self-report tools that have individually demonstrated >75% accuracy in predicting 12-month outcomes when administered in the first weeks from injury, new interpretations of common pain assessment and evaluation tools, and new frameworks for understanding pain and its management at both the acute and chronic stages. The investigators have used advanced analytic techniques to identify and describe the recovery trajectories present in a sample of people with mixed musculoskeletal injuries using data collected within days to weeks, predicting outcomes up to 12 months post-injury. In a recently-completed project, some of these innovations were integrated into a single online questionnaire targeting Canadian military veterans with chronic pain. The results of that analysis revealed a 5-cluster solution based on responses to self-report measures of 7 domains (or axes) of drivers of the pain experience. The investigators believe this strategy will also have value when translated and implemented in more acutely injured workers in Canada as a single risk stratification and management protocol. The longer-term goal is to use this type of simple self-assessment protocol to empower injured workers and claims managers to triage into the right care pathway, reduce time off work, and improve the likelihood of successful outcomes.

Based on our team's extensive work in the prognosis of post-traumatic musculoskeletal injuries, the investigators propose that it is possible to identify those who can be expected to achieve a full return to work within only the programs of care and differentiate them from those who will experience some form of delayed or non-return to work and can do so within the first 3 weeks (21 days) from injury with >80% accuracy.

Objective Development and validation of a multi-axis 'risk/prognosis' worker-reported screening tool comprising tools that can be administered within the first 8 weeks of work-related injury and provide >80% accuracy in predicting work recovery trajectories over the subsequent 2 months.

Recruitment Recruitment will occur through CBIH programs of care provider clinics for injured workers, using both emailed and posted invitations. In both cases explicit opt-in consent will be obtained for this study following the protocol for digital online consent procedures from Western's Research Ethics Board (REB).

Members of the research team at Western will monitor the portal for new participants daily. New participants will be entered into a Master List that includes only name, contact email address, and a study-specific randomly-generated 4-digit ID number. The Master List is necessary to permit the linking of responses across data collection periods and will be stored separately from the raw data file that will include only ID number. The research team member will subsequently create a unique survey link tied to the participant's email addresses and send that to the participant within two working days. That survey will start with the screening questions for inclusion. Those who pass the screen will proceed with the full set of survey questions, while those who are screen-failed will be presented with a thank participant screen and their study involvement will end. Upon entry into the Master List, follow-up dates at 1 and 2 months post-inception will be automatically calculated, and the research team members will use those to ensure follow-up survey forms are sent on time.

Clinician Feedback: The emailed link to the clinician feedback survey will be sent to all members of the CBI Health Inc. network of physiotherapists in Canada, along with the new classification tool/algorithm. The CBI Health collaborators on this protocol will facilitate dissemination of the link through internal CBI Health email channels. Any clinician who is a registered physiotherapist within the CBI Health Inc. network will be eligible to participate. They will receive the new stratification algorithm and a link to a single-page feedback survey. In this way emails will be stored in a separate database from survey responses. The list of emails will remain with the Western researchers and will not be shared with the CBI Health leadership.

Methodology This is an observational prospective inception cohort using data collected from injured workers entering one of the CBIH programs of care. Clinicians within this network provide care under a standardized framework that limits confounding from different interventions and the researchers will not manipulate treatment decisions.

Duration: All eligible Workers will be invited to participate. Participants will be in the study for two months (8 weeks) total, from inception to outcome. A single interim data collection at 4 weeks post-inception will permit longitudinal trajectories to be established for each outcome as a tertiary analytic target (interpreted as slope/rate of recovery).

DATA ANALYSIS: 1. Descriptive and bivariate associations to describe the sample and evaluate associations between the predictors and the outcomes; 2. Maximum likelihood-based latent profile analysis in which the predictors (and their subscales where available) are used to identify meaningful profiles ('clusters') of injured Workers. This will be guided by 3 core principles of i) statistical justification, ii) parsimony, and iii) clinical meaningfulness; 3. The profiles will then be evaluated to determine the proportion of successful primary (work) and secondary outcomes within each. The investigators anticipate that one profile will comprise a majority who achieve Full return to work by 8 weeks and another will comprise a majority who fail to achieve return to work, with other clusters including mixed outcomes. Prognostic accuracy of the new clusters will also be compared against the TIDS to determine whether the use of additional scales offers improved utility over the single scale.

SAMPLE SIZE: Prior authors have endorsed at least 250 unique people in the data for robust Maximum likelihood-based latent profile analyses, and our own work in a sample of Canadian military veterans with chronic pain that used almost identical indicators to the current project successfully identified 5 latent classes with n = 322 respondents. The investigators will target up to n = 350 over a two-year project window.

Quality Assurance: All Western members of the research team have completed either or both of the Good Clinical Practice or Tri-Council Policy Statement 2 training modules. Certificates of completion are available upon request. Further, the Principal Investigator has completed the CIHR Institute of Gender training module on sex- and gender-based analyses, Equity, Diversity and Inclusion training through Western University, and Ownership, Control, Access and Possession training for research with Indigenous peoples.

The investigators acknowledge a potential for conflict of interest regarding the collaboration with the CBIH team. Importantly, CBIH will be instrumental for helping meet the recruitment targets as one of Canada's largest networks of rehabilitation providers for injured workers. Members of the CBIH team will also be critical for ensuring the design described herein can be expected to lead to implementable findings, and they will facilitate clinical interpretation of analytic results, and facilitate dissemination of the findings throughout their network of clinics. Importantly, all findings of this work will be published in scientifically-rigourous peer-reviewed journals relevant to the field, and no part of the data or findings will be the proprietary property of CBIH. Participants will be made aware of this arrangement prior to providing their informed consent to participate.

Expected Outcomes:

This work is anticipated to result in a new risk/prognosis screening tool to discriminate between those injured workers most likely to transition back to full return to work quickly from those most likely to experience delayed or incomplete recovery, and the investigators further anticipate that the latent classes identified will be useful for directing injured workers to the most appropriate health discipline in the patient-centred spirit of 'right care, right person, right time'. Logical next steps from this work will be to use the most accurate predictor variables found herein to create and test intervention strategies that specifically target the risks present in higher-risk injured workers. Through this program of research, the investigators anticipate reducing the burden of delayed return to work borne by both injured workers and those who insure them.

Ethics: All methods for this study have been approved by the Health Sciences Research Ethics Board of Western University (London Ontario, Canada), REB No. 121883, having been evaluated by an independent peer reviewer against the standards of the Declaration of Helsinki and in accordance with the Tri-Council Policy Statement 2.

Inclusion Criteria: Eligible participants are those aged ≥18 years, able to read 6th grade English, presenting to a program of care for rehabilitation of a workplace injury with a primary musculoskeletal or Low Back Pain component.

Exclusion Criteria: Participants with significant cognitive impairment or learning disability (self-reported) that interfere with following multi-step instructions will be excluded from this study. The exclusive focus on those entering program of care-based rehab will naturally exclude workers with catastrophic injuries (e.g., loss of limb, multiple fractures, burns) or those for whom a mental health disorder (e.g., PTSD, depression) is the primary diagnosis, thereby homogenizing the types of injuries included.

This is an observational prospective inception cohort using data collected from injured workers entering one of the CBIH programs of care.

Upon study completion, we will pursue options for making the de-identified data open-access through engagement with the REB around safe and ethical data sharing.

Upon study completion

Open access and administrative database.