Validation of the Subgroups for Targeted Treatment for Back (STarT Back) screening tool at a tertiary care centre

Background: The Subgroups for Targeted Treatment for Back (STarT Back) tool is a screening questionnaire developed to identify modifiable risk factors for back pain disability in primary care. Given the ability of this tool to assist with early identification of patients at high risk, we examined its concurrent convergent and known-group construct validity in tertiary care. Methods: This was a case-control study of adult (age > 18 yr) patients with and without an active work-related compensation claim recruited from an academic health centre between August 2017 and May 2019. Patients in the study group were assessed by a physiotherapist and an orthopedic surgeon in a spine specialty program designed to assess and treat workplace injuries. The control group included patients referred to an orthopedic spine surgeon in a publicly funded specialty clinic where an advanced practice physiotherapist determined the need for surgical consultation. We used the Roland-Morris Disability Questionnaire (RMDQ) and the Hospital Anxiety and Depression Scale (HADS) to determine the convergent and known-group construct validity of the STarT Back tool. Results: Fifty case and 50 control participants were included. We observed moderate to high association between the STarT Back total score, psychosocial subscore and risk categories and the RMDQ and HADS scores in the expected direction (p < 0.001). A significant association was observed between risk group allocation and depression (area under the curve values > 80), having a compensable injury and work status (p = 0.002-0.001). Conclusion: The STarT Back tool was able to differentiate between patients with and without a compensable injury and patients with different levels of work status. The tool has acceptable convergent and known-group construct validity and can assist in clinical decision making in a tertiary care setting where adjunct psychologic management may be indicated.