Operative Management of Adult Spinal Deformity Results in Significant Increases in QALYs Gained Compared to Nonoperative Management

Study Design. Retrospective review of prospective multicenter adult spinal deformity (ASD) database. Objective. To compare the quality-adjusted life years (QALYs) between operative and nonoperative treatments for ASD patients. Summary of Background Data. Operative management of ASD repeatedly demonstrates improvements in HRQOL over nonoperative treatment. However, little is reported regarding QALY improvements after surgical correction of ASD. Methods. Inclusion criteria: ≥18 years, ASD. Health utility values were calculated from SF6D scores and used to calculate QALYs at minimum 2 years from the baseline utility value as well as at 1, 2, and 3 years for the available patients. A 1:1 propensity score matching using six baseline variables was conducted to account for the nonrandom distribution of operative and nonoperative treatments. Results. Four hundred seventy-nine patients were included (OP:258, 70.7%, NONOP:221, 47.1%). One hundred fifty-one (OP:90, NONOP:61) had complete 1, 2, and 3 year data available for QALY trending. Unmatched results are not listed in the abstract. Mean baseline utility scores were statistically similar between the matched groups (OP: 0.609 ± 0.093, NONOP: 0.600 ± 0.091, P = 0.6401) and at 2 year min postop mean OP QALY was greater than NONOP (1.377 ± 0.345 vs. 1.256 ± 0.286, respectively, P < 0.01). For the subanalysis cohort, mean OP QALYs at 1, 2, and 3 years postoperative were all significantly greater than NONOP, P < 0.03 for all (1 yr: 0.651 ± 0.089 vs. 0.61 ± 0.079, 2 yr: 1.29 ± 0.157 vs. 1.189 ± 0.141, and 3 yr: 1.903 ± 0.235 vs. 1.749 ± 0.198, respectively). Matched OP had a larger QALYs gained (from baseline) at 2 year minimum postoperative (0.112 ± 0.243 vs. 0.008 ± 0.195, P < 0.01). For subanalysis of patients with complete 1 to 3 years data, OP had a significantly larger QALYs gained at 1, 2, and 3 years compared with NONOP: 1 year (0.073 ± 0.121 vs. 0.029 ± 0.082, P = 0.0447), 2 years (0.167 ± 0.232 vs. 0.036 ± 0.173, P = 0.0030), and 3years (0.238 ± 0.379 vs. 0.059 ± 0.258, P < 0.01). Conclusion. The operative treatment of adult spinal deformity results in significantly greater mean QALYs and QALYs gained at minimum 2 years postop as well as at the 1-, 2-, and 3-year time points compared with nonoperative management.