Tolerance for Adverse Events from Operative and Nonoperative Treatment for Mild Cervical Spondylotic Myelopathy

Background. Guidelines recommend surgery for moderate and severe cervical spondylotic myelopathy (CSM) but support either surgery or nonoperative care for mild disease. How patients weigh the adverse events associated with each pathway is not well characterized. Methods. We conducted a three-arm randomized vignette experiment among United States adults aged 40 years and older recruited through an online research panel. All participants read an identical description of mild CSM and were randomized to one of three scenarios: surgery that improved symptoms, surgery that halted progression without improvement, or nonoperative management with symptom progression. Participants in the surgical scenarios rated 12 possible complications and those in the nonoperative scenario rated 8 progression outcomes. For each item, participants rated how strongly it would influence their decision (0-10) and whether they would still choose the same treatment. Items for which participants would no longer choose the same treatment were termed dominant decision factors. Results. Of 276 respondents, 263 (95.2%) were analyzed. Dominant factor rates ranged from 13.5% to 87.8% across complications. Complications described as persisting at one year produced substantially higher rates than the same complications described as resolving by three months. Adverse events more frequently constituted dominant factors when surgery was framed as offering less benefit, although differences between scenarios were not statistically significant. In the nonoperative scenario, worsening bladder control (56.6%) and neck pain interfering with sleep (53.0%) were the strongest influences, exceeding needing a cane to walk (32.1%). Conclusions. Treatment decisions for mild CSM are driven primarily by the expected permanence of adverse events and their anticipated impact on daily quality of life, rather than by conventional neurological metrics or surgical benefit framing.