Development and feasibility of the AO spinal metastasis staging (SMS) referral tool: An international multidisciplinary expert panel and survey study

PURPOSE: Spinal metastases may progress to debilitating pain, spinal instability, and neurological deficits. Timely referral is essential, yet delays are common because patients often first present to non-spine clinicians where red flags rarely expedite referral and guidelines primarily target spine specialists. We aimed to develop a staging-based referral tool to support non-spine clinicians in recognizing progression and guiding referral urgency. METHODS: We defined the Spinal Metastasis Staging (SMS) system as four stages: SMS I, asymptomatic; SMS II, inflammatory pain; SMS III, mechanical pain and/or spinal instability; and SMS IV, neurological deficits and/or high-grade spinal cord compression. Stages were translated into a referral algorithm organized by urgency and presented as a pocket map. The tool was refined through regional and international multidisciplinary expert panels, and feasibility was evaluated in an international survey. RESULTS: Panels endorsed the four-stage SMS system and referral algorithm. Among all survey respondents (n = 120), high acceptability was reported. Among non-spine clinicians (n = 32), 94% found the tool easy to understand, 91% considered the format suitable for clinical use, and 91% anticipated improved referrals. Overall, 88% would use the tool at least occasionally, including 55% who would use it frequently or always. CONCLUSION: The SMS staging system and referral tool (link) was rated feasible by expert panels and survey respondents. However, only 32 of 120 survey respondents (27%) were non-spine clinicians, so findings in this group are preliminary and may overstate acceptance. The tool should be considered provisional: prospective studies are needed to validate effects on referral and patient outcomes.