P70. Frailty does not negatively impact cost utility in adult spinal deformity

Abstract

BACKGROUND CONTEXT The Adult Spinal Deformity Frailty Index (ASD-FI), a validated modality for quantifying frailty, stratifies patients into categories not frail (NF), frail (F) and severely frail (SF). However, the cost of treating each frailty state is unknown. PURPOSE Investigate the cost utility of treating not frail versus frail or severely frail ASD patients. STUDY DESIGN/SETTING Retrospective review of a prospective single center adult spinal deformity database. PATIENT SAMPLE A total of 79 operative and non operative ASD patients ≥18 years old, with baseline and 2Y ASD-FI and Oswestry Disability Index (ODI) scores. OUTCOME MEASURES ODI, SF-6D, Cost per quality adjusted life years (QALY), Incremental Cost Effectiveness, Ratio (ICER). METHODS Inclusion criteria was surgical ASD (scoliosis≥20°, SVA≥5cm, PT≥25°, or thoracic kyphosis ≥60°) patients >18 years with available frailty and ODI data at BL and 2-years post op. Independent T-Tests assessed baseline radiographic differences in PT, PI-LL, and Schwab SVA modifier status between NF vs. F/SF patients. Utility data was calculated using the ODI converted to the SF-6D using published conversion methods. QALYs utilized a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs were calculated using the PearlDiver database. After accounting for complications, LOS, revisions, and death, cost per QALY at 2Y and life expectancy were calculated for NF, and F/SF patients. ICER was compared between non op and operative NF and F/SF patients at 2Y and life expectancy. RESULTS Seventy-nine ASD patients met inclusion criteria. Descriptive statistics for the cohort were: age 51.0±6.8, 76% women, BMI 26.7±6.8, 54% osteotomy, 54% decompression, and 11.6±4.2 average levels fused. At BL, there were 48 NF, 26 F, and 4 SF pts. The average BL frailty for NF pts was 0.13±0.08, 0.39±0.06 for F, and 0.59±0.08 for SF pts. There were no differences in PT, PI-LL, or severe SVA Schwab modifier grades between NF or F/SF pts (all p>0.05). At 2-year follow up, there was no difference in the average cost of ASD surgery, $91,068.98 for NF patients and $90,888.53 for F/SF pts (p>0.05). The cost per QALY was higher for NF pts at 2 years vs F/SF pts ($464,239.62 vs. $321,107.89, p CONCLUSIONS Frail and severely frail patients had lower cost per QALY compared to not frail patients at 3 years and life expectancy. In addition, when compared to a non operative cohort of ASD patients, frail and severely frail patients had lower ICER values. While these results support operative correction of frail and severely frail patients, it is important to note that these patients are often at worse baseline disability, which is closely related to frailty scores, and have more opportunity to improve postoperatively. In addition, there may be a threshold of frailty that is not operable due to the risk of severe complications that is not captured by this analysis. While future research should investigate economic outcomes at extended follow-up times, these findings support the cost effectiveness of ASD surgery at all frailty states. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.