The Influence of Multilevel Spinal Deformity Surgery on the EuroQol 5 Dimensions’ (EQ-5D) Questionnaire and Residential Status in the Elderly: A Prospective, Observational, Multicenter Study

Study Design: Multicenter, international prospective study. Objective: This study investigated the clinical outcome up to 2 years after multi-level spinal deformity surgery in the elderly by reporting the minimal clinically important difference (MCID) of EuroQol 5-dimensions (EQ-5D), EQ-VAS, and residential status. Methods: As an ancillary study of 219 patients ≥60 years with spinal deformity undergoing primary instrumented fusion surgery of ≥5 levels, this study focuses on EQ-5D (3-L) as the primary outcome and EQ-VAS and residential status as secondary outcomes. Data on EQ-5D were compared between pre-operatively and postoperatively at 10 weeks, 12 months, and 24 months. An anchor-based approach was used to calculate the MCID. Results: The EQ-5D index and EQ-VAS, respectively, improved significantly at each time point compared to pre-operatively (from.53 (SD.21) and 55.6 (SD 23.0) pre-operatively to.64 (SD.18) and 65.8 (SD 18.7) at 10 weeks,.74 (SD.18) and 72.7 (SD 18.1) at 12 months, and.73 (SD.20) and 70.4 (SD 20.4) at 24 months). 217 (99.1%) patients lived at home pre-operatively, while 186 (88.6%), 184 (98.4%), and 172 (100%) did so at 10 weeks, 12 months, and 24 months, respectively. Our calculated MCID for the EQ-5D index at 1 year was.22 (95% CI.15-.29). Conclusions: The EQ-5D index significantly increased at each time point over 24 months after ≥5 level spinal deformity surgery in elderly patients. The MCID of the EQ-5D-3 L was.22. Patients living at home pre-operatively can expect to be able to live at home 2 years postoperatively.