Development and feasibility of the AO spinal metastasis staging (SMS) referral tool: An international...

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.

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.

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.

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.