The utility of the Risk Assessment and Prediction Tool in predicting discharge disposition, length of stay, and readmissions in patients undergoing transforaminal lumbar interbody fusion.
Abstract
Objective
The Risk Assessment and Prediction Tool (RAPT) has been utilized to anticipate discharge needs after procedures such as total joint arthroplasty. Its usefulness for spine patients, particularly those undergoing transforaminal lumbar interbody fusion (TLIF), has not been clearly established. This study evaluated the relationship between the preoperative RAPT score and 3 postoperative outcomes: discharge destination, hospital length of stay (LOS), and 30-day readmission.
Methods
A retrospective cohort study was conducted of adults who underwent elective TLIF with a recorded preoperative RAPT score. RAPT was analyzed as a continuous variable. Home discharge and 30-day readmission were modeled with logistic regression, and LOS with linear regression. Multivariable models adjusted for age, sex, Charlson Comorbidity Index (CCI), and insurance type. Discrimination for facility discharge was assessed by receiver operating characteristic (ROC) analysis at literature-aligned thresholds (RAPT scores 9.5 and 8.5: balanced and conservative, respectively).
Results
Among 116 patients, the mean age was 62.2 years and 50.9% of patients were female; the mean BMI was 29.9, and the mean CCI was 5.64. The mean RAPT score was 9.65, and the mean LOS was 3.14 days. Discharge to a skilled nursing or rehabilitation facility occurred in 6.9% of patients, and 30-day readmission occurred in 6.0%. Each 1-point increase in the RAPT score was associated with higher odds of home discharge (univariate: OR 1.74, 95% CI 1.11-2.73, p = 0.016; multivariable: OR 2.17, 95% CI 1.24-3.80, p = 0.007) and a shorter LOS (β = -0.38 days, 95% CI -0.71 to -0.05, p = 0.025; adjusted β = -0.39, bootstrap 95% CI -0.76 to -0.10, p = 0.038). The RAPT score was not associated with 30-day readmission (adjusted OR 0.93, 95% CI 0.52-1.65; p = 0.798). ROC analysis for predicting facility discharge showed moderate discrimination with an area under the curve of 0.709 (95% CI 0.543-0.876, p = 0.049), with sensitivity 63% and specificity 62% at 9.5, and sensitivity 38% and specificity 82% at 8.5. Youden's index revealed an optimal cutoff of 10.5, with sensitivity 100% and specificity 29.6%.
Conclusions
In patients undergoing TLIF, higher preoperative RAPT scores were associated with greater odds of home discharge and shorter LOS. RAPT may serve as a practical preoperative tool to support discharge planning and resource allocation in spine surgery.