Spinal Epidural Abscess Patients Have Higher Modified Frailty Indexes Than Back Pain Patients on Emergency Room Presentation: A Single-Center Retrospective Case-Control Study

Keeping It Simple: Developing a Prognostic Tool for Spinal Epidural Abscess

STUDY DESIGN

A retrospective study.

OBJECTIVE

To develop a prognostic score for mortality and treatment failure in Spinal epidural abscess (SEA), based on simplicity and multidimensional assessment principles.

METHODS

One-hundred-fifty patients were reviewed. Variables assessed included comorbidities, functional status, clinical presentation, Frankel classification, and biochemical and radiological parameters. The main outcomes were the 90-day mortality and treatment failure, corresponding to any intensification of the initial treatment plan. Variables were sorted out with a factorial analysis. Logistic regressions were performed, and the new score was derived from the coefficients. ROC curves with Area Under Curve, calibration plots, and cross-validation were performed.

RESULTS

Forty-three patients (29%) had treatment failure, and 15 died (10%) by 90 days. Factorization created 3 groups: Comorbidities (C), Severity (S), and Function (F). For 90-day mortality, Odds ratios were 1.20 (P = .0002), 1.15, (P = .03), 1.36, (P < 10-4) for C, S, F, respectively. The new score 'CSF' had 1 point per item, ranging from zero to 3. OR increased by 1.2/point for 90-day mortality (P < 10-4), AUC was .86. For failures OR increased by 1.15/point (P = .014), AUC was .58, and increased to .64 for patients who survived after 90 days, probably due to competing risks.

CONCLUSIONS

Comorbidities, Severity, and Function is a new simplistic tool, easy to use in daily practice; its performances were excellent for 90-day mortality, and acceptable for failures. Simple tools are more likely to be adopted into practice. External validation of this technique is desirable.

The 5-item modified frailty index predicts spinal osteotomy outcomes better than age in adult spinal deformity patients: an ACS - NSQIP analysis

PURPOSE

To evaluate the utility of 5-Item Modified Frailty Index (mFI-5) as compared to chronological age in predicting outcomes of spinal osteotomy in Adult Spinal Deformity (ASD) patients.

METHODS

Using Current Procedural and Terminology (CPT) codes, the American College of Surgeons National Surgery Quality Improvement Program (ACS-NSQIP) database was queried for adult patients undergoing spinal osteotomy from 2015 to 2019. Multivariate regression analysis was performed to evaluate the effect of baseline frailty status, measured by mFI-5 score, and chronological age on postoperative outcomes. Receiver-operating characteristic (ROC) curve analysis was performed to analyze the discriminative performance of age versus mFI-5.

RESULTS

A total of 1,789 spinal osteotomy patients (median age 62 years) were included in the analysis. Among the patients assessed, 38.5% (n = 689) were pre-frail, 14.6% frail (n = 262), and 2.2% (n = 39) severely frail using the mFI-5. Based on the multivariate analysis, increasing frailty tier was associated with worsening outcomes, and higher odds ratios (OR) for poor outcomes were found for increasing frailty tiers as compared to age. Severe frailty was associated with the worst outcomes, e.g., unplanned readmission (OR 9.618, [95% CI 4.054-22.818], p < 0.001) and major complications (OR 5.172, [95% CI 2.271-11.783], p < 0.001). In the ROC curve analysis, mFI-5 score (AUC 0.838) demonstrated superior discriminative performance than age (AUC 0.601) for mortality.

CONCLUSIONS

The mFI5 frailty score was found to be a better predictor than age of worse postoperative outcomes in ASD patients. Incorporating frailty in preoperative risk stratification is recommended in ASD surgery.

External validation of a predictive algorithm for in-hospital and ninety-day mortality after spinal epidural abscess

BACKGROUND CONTEXT

Mortality in patients with spinal epidural abscess (SEA) remains high. Accurate prediction of patient-specific prognosis in SEA can improve patient counseling as well as guide management decisions. There are no externally validated studies predicting short-term mortality in patients with SEA.

PURPOSE

The purpose of this study was to externally validate the Skeletal Oncology Research Group (SORG) stochastic gradient boosting algorithm for prediction of in-hospital and 90-day postdischarge mortality in SEA.

STUDY DESIGN/SETTING

Retrospective, case-control study at a tertiary care academic medical center from 2003 to 2021.

PATIENT SAMPLE

Adult patients admitted for radiologically confirmed diagnosis of SEA who did not initiate treatment at an outside institution.

OUTCOME MEASURES

In-hospital and 90-day postdischarge mortality.

METHODS

We tested the SORG stochastic gradient boosting algorithm on an independent validation cohort. We assessed its performance with discrimination, calibration, decision curve analysis, and overall performance.

RESULTS

A total of 212 patients met inclusion criteria, with a short-term mortality rate of 10.4%. The area under the receiver operating characteristic curve (AUROC) of the SORG algorithm when tested on the full validation cohort was 0.82, the calibration intercept was -0.08, the calibration slope was 0.96, and the Brier score was 0.09.

CONCLUSIONS

With a contemporaneous and geographically distinct independent cohort, we report successful external validation of a machine learning algorithm for prediction of in-hospital and 90-day postdischarge mortality in SEA.

Frailty as a Superior Predictor of Dysphagia and Surgically Placed Feeding Tube Requirement After Anterior Cervical Discectomy and Fusion Relative to Age

Frailty is a measure of physiological reserve that has been demonstrated to be a discriminative predictor of worse outcomes across multiple surgical subspecialties. Anterior cervical discectomy and fusion (ACDF) is one of the most common neurosurgical procedures in the United States and has a high incidence of postoperative dysphagia. To determine the association between frailty and dysphagia after ACDF and compare the predictive value of frailty and age. 155,300 patients with cervical stenosis (CS) who received ACDF were selected from the 2016-2019 National Inpatient Sample (NIS) utilizing International Classification of Disease, tenth edition (ICD-10) codes. The 11-point modified frailty index (mFI-11) was used to stratify patients based on frailty: mFI-11 = 0 was robust, mFI-11 = 1 was prefrail, mFI-11 = 2 was frail, and mFI-11 = 3 + was characterized as severely frail. Demographics, complications, and outcomes were compared between frailty groups. A total of 155,300 patients undergoing ACDF for CS were identified, 33,475 (21.6%) of whom were frail. Dysphagia occurred in 11,065 (7.1%) of all patients, and its incidence was significantly higher for frail patients (OR 1.569, p < 0.001). Frailty was a risk factor for postoperative complications (OR 1.681, p < 0.001). Increasing frailty and undergoing multilevel ACDF were significant independent predictors of negative postoperative outcomes, including dysphagia, surgically placed feeding tube (SPFT), prolonged LOS, non-home discharge, inpatient death, and increased total charges (p < 0.001 for all). Increasing mFI-11 score has better prognostic value than patient age in predicting postoperative dysphagia and SPFT after ACDF.