Evolution of Patient-Reported Outcome Measures After Surgery for Degenerative Cervical Spine Disease: Do 1-year PROMs Reflect Longer Term Outcomes?

Background and objectives: Patient-reported outcome measures (PROMs) are today's gold standard outcomes in surgery for degenerative cervical spine disorders. Long-term outcome research may be limited by missing data at later follow-up time-points. Previous studies on lumbar disorders suggest that no significant changes to PROMS occur after 1-year postsurgery. However, no previous study has examined the evolution of PROMS after surgery for degenerative cervical spine disease. We hence aimed to study the evolution of PROMs at 1, 2, and 5 years of postoperative follow-up in patients with cervical spondylosis treated for degenerative radiculopathy or myelopathy. Methods: A total of 6467 patients (4785 radiculopathy and 1682 myelopathy) undergoing surgery for cervical spondylosis between 2006 and 2018 in Sweden were included. Prerequisites for inclusion were PROMs at 1 and 2 or 5 years. The evolution of PROMs over time, the correlation between 1-year PROMs and 2- or 5-year PROMs and the predictive capability of 1-year PROMs were assessed. Conclusions: After surgery for cervical spondylosis with either degenerative radiculopathy or myelopathy, PROMs remained stable beyond 1 year, with minimal changes occurring thereafter. 1-year PROMs correlated with and served as a good proxy for predicting 2- and 5-year PROMs. This suggests that on a population level, 1-year PROMs are sufficient to assess longer term outcomes.