27. Costs and utility of postdischarge acute inpatient rehabilitation following adult spinal deformity surgery

Abstract

BACKGROUND CONTEXT As the United States' health care system transitions to a value-based approach, defining costs for entire episodes of care is fundamental to determining value. This is particularly important for adults with spinal deformity (ASD) who undergo surgical intervention. PURPOSE To further the discussion on costs of operative care for ASD, this study aims to evaluate the costs and functional utility of postdischarge acute inpatient rehabilitation after surgery for ASD. STUDY DESIGN/SETTING Single-center, retrospective cohort analysis. PATIENT SAMPLE Adults with spinal deformity (ASD) who underwent operative intervention (>7 levels fused) at a single tertiary care referral center and who were discharged postoperatively to one acute inpatient rehabilitation facility. OUTCOME MEASURES Patient demographics, operative details, direct costs and length of stay for inpatient hospitilization and acute postoperative rehabilitation, and patient function, as assessed by the Functional Independence Measure (FIM) instrument. METHODS Patient demographics, operative details, and costs were obtained for the index operation's inpatient encounter. Data for acute rehabilitation included: direct costs, length of stay, and patient function, as assessed by the Functional Independence Measure (FIM) instrument [scores 18-30 (total assistance), 31-45 (maximal assistance), 46-63 (moderate assistance), 64-80 (minimal assistance), 81-100 (supervision), 101-125 (modified independence), 126 (complete independence)]. Student T-tests and Chi-square tests were used to compared continuous and categorical variables. Pearson's tests were used to assess correlations. p RESULTS Ninety patients (95 episodes of care; average age 70.5±10.6 years; male-31, female-59) were included. After operations, average inpatient length of stay was 8.2±2.6 days (4-16 days). Operative details included: posterior levels fused 13.6±3.6 (7-21 levels), posterior column osteotomies (per patient) 7±3.7 (range, 1-15; n=49 patients), forty-two 3COs (PSO-35, VCR-7), and 11 interbody fusions. Average direct costs were $90,738±$24,166 ($36,521–$141,090) for index inpatient stays and $38,808±$14,752 ($8,679–$100,829) for post-discharge acute rehabilitation (Figure 1). Patients spent an average of 11.7±4.0 days (2-28 days) in acute rehabilitation postdischarge. Average direct cost per day in rehabilitation was $3,338 ±$2,131 ($506-$4,340). Significant improvements in function (FIM) were observed [admit: 66±14 (15–91) vs discharge: 94±14 (54–116); % improvement: 29±14]. CONCLUSIONS Postdischarge inpatient acute rehabilitation following operations for adult spinal deformity is associated with an average direct cost of $38,808 per case. While rehabilitation resulted in significant functional improvements, it came at a very significant economic expense amounting to $3.7 million, which accounted for 30% of the costs for 95 episodes of care. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.