Prediction of Discharge Status and Readmissions after Resection of Intradural Spinal Tumors

Abstract

Objective: Intradural spinal tumors are uncommon and while associations between clinical characteristics and surgical outcomes have been explored, there remains a paucity of literature unifying diverse predictors into an integrated risk model. To predict postresection outcomes for patients with spinal tumors.

Methods: IBM MarketScan Claims Database was queried for adult patients receiving surgery for intradural tumors between 2007 and 2016. Primary outcomes-of-interest were nonhome discharge and 90-day postdischarge readmissions. Secondary outcomes included hospitalization duration and postoperative complications. Risk modeling was developed using a regularized logistic regression framework (LASSO, least absolute shrinkage and selection operator) and validated in a withheld subset.

Results: A total of 5,060 adult patients were included. Most surgeries utilized a posterior approach (n = 5,023, 99.3%) and tumors were most commonly found in the thoracic region (n = 1,941, 38.4%), followed by the lumbar (n = 1,781, 35.2%) and cervical (n = 1,294, 25.6%) regions. Compared to models using only tumor-specific or patient-specific features, our integrated models demonstrated better discrimination (area under the curve [AUC] [nonhome discharge] = 0.786; AUC [90-day readmissions] = 0.693) and accuracy (Brier score [nonhome discharge] = 0.155; Brier score [90-day readmissions] = 0.093). Compared to those predicted to be lowest risk, patients predicted to be highest-risk for nonhome discharge required continued care 16.3 times more frequently (64.5% vs. 3.9%). Similarly, patients predicted to be at highest risk for postdischarge readmissions were readmitted 7.3 times as often as those predicted to be at lowest risk (32.6% vs. 4.4%).

Conclusion: Using a diverse set of clinical characteristics spanning tumor-, patient-, and hospitalization-derived data, we developed and validated risk models integrating diverse clinical data for predicting nonhome discharge and postdischarge readmissions.

Keywords: Intradural spine tumor; Machine learning; Predictive modeling.

Fig. 1.

Cohort summary and contributors to increased hospitalization duration. (A) Trends in operative microscope and intraoperative neuromonitoring use. (B) Slope and 95% confidence intervals reflect the line-of-best-fit. Multivariable assessment of variable contributions to postsurgical hospitalization length is presented. Comorbidities not depicted (see Supplementary Table 2). CI, confidence interval; NOS, not otherwise specified.

Fig. 2.

Predictive modeling of nonhome discharge. Model performance for predicting nonhome discharge following intradural tumor resection was evaluated in the withheld validation subset. (A) Integrated model discrimination was compared to that of models utilizing only feature subsets. Empiric nonhome discharge rates were computed based on predicted risk strata (B), and the top 8 contributing features are visualized (C). AUC, area under the curve.

Fig. 3.

Application of nonhome discharge numerical risk score for prediction of nonhome discharge. Conversion of numerical risk scores to empiric nonhome discharge risk demonstrates good stratification in both training and validation subsets.

Fig. 4.

Predictive modeling of postdischarge readmissions. Model performance was evaluated on the withheld validation subset. (A) Discrimination ability was compared between the integrated risk model and models utilizing only feature subsets. Empiric 90-day readmission frequency was computed based on predicted risk strata (B), and the top 8 contributing features are visualized (C). AUC, area under the curve.