The immense heterogeneity of frailty in neurosurgery: a systematic literature review

Hospital frailty risk score predicts high-value care outcomes following brain metastasis resection

OBJECTIVE

Brain metastases (BM) are the most common adult intracranial tumors, representing a significant source of morbidity in patients with systemic malignancy. Frailty indices, including 11- and 5-factor modified frailty indices (mFI-11 and mFI-5), American Society of Anesthesiologists (ASA) physical status classification, and Charlson Comorbidity Index (CCI), have recently demonstrated an important role in predicting high-value care outcomes in neurosurgery. This study aims to investigate the efficacy of the newly developed Hospital Frailty Risk Score (HFRS) on postoperative outcomes in BM patients.

METHODS

Adult patients with BM treated surgically at a single institution were identified (2017-2019). HFRS was calculated using ICD-10 codes, and patients were subsequently separated into low (<5), intermediate (5-15), and high (>15) HFRS cohorts. Multivariate logistic regressions were utilized to identify associations between HFRS and complications, length of stay (LOS), hospital charges, and discharge disposition. Model discrimination was assessed using receiver operating characteristic (ROC) curves.

RESULTS

A total of 356 patients (mean age: 61.81±11.63 years; 50.6 % female) were included. The mean±SD for HFRS, mFI-11, mFI-5, ASA, and CCI were 6.46±5.73, 1.31±1.24, 0.95±0.86, 2.94±0.48, and 8.69±2.07, respectively. On multivariate analysis, higher HFRS was significantly associated with greater complication rate (OR=1.10, p<0.001), extended LOS (OR=1.13, p<0.001), high hospital charges (OR=1.14, p<0.001), and nonroutine discharge disposition (OR=1.12, p<0.001), and comparing the ROC curves of mFI-11, mFI-5, ASA,and CCI, the predictive accuracy of HFRS was the most superior for all four outcomes assessed.

CONCLUSION

The predictive ability of HFRS on BM resection outcomes may be superior than other frailty indices, offering a new avenue for routine preoperative frailty assessment and for managing postoperative expectations.

Frailty Predicts in-Hospital Death in Traumatic Brain Injury Patients: A Retrospective Cohort Study

Background and Aim

Traumatic brain injury (TBI) is a severe public health problem in elderly patients, and frailty is associated with higher mortality rates in older patients. This study aims to assess the prognostic value of frailty in patients with TBI.

Methods

Clinical data from 348 TBI patients treated at Affiliated Kunshan Hospital of Jiangsu University and Kunshan Hospital of Traditional Chinese Medicine between December 2018 and December 2020 were retrospectively collected. Univariate and multivariate logistic regression analyses were used to determine risk factors affecting in-hospital mortality, and receiver operating characteristic (ROC) curves were plotted to assess the discriminatory power of the frailty index. Frailty was assessed using the FRAIL scale, where FRAIL stands for Fatigue, Resistance, Ambulation, Illness, and Loss of weight, with each item scored as 0 or 1.

Results

Using the FRIAL questionnaire, 122 patients had low frailty and 226 had high frailty. Multivariate logistic regression analysis showed that high frailty was a risk factor for in-hospital mortality in TBI patients (P<0.001, OR=2.012 [1.788-2.412]). The proportion of infections occurring in the two groups was statistically different (P=0.015), with severely infected TBI patients being more likely to develop complications. The ROC curve showed an area under the curve for the FRAIL score of 0.845 [0.752-0.938].

Conclusion

Frailty is an important risk factor for in-hospital mortality in elderly TBI patients, and more attention should be paid to patients with high levels of frailty. Clinicians should consider the degree of frailty when assessing TBI and making treatment decisions.

Frailty is a risk factor for intracranial abscess and is associated with longer length of stay: a retrospective single institution case-control study

BACKGROUND

Intracranial abscess (IA) causes significant morbidity and mortality. The impact of baseline frailty status on post-operative outcomes of IA patients remains largely unknown. The present study evaluated if frailty status can be used to prognosticate outcomes in IA patients.

METHODS

We retrospectively reviewed all IA patients undergoing craniotomy at our institution from 2011 to 2018 (N.=18). These IA patients were age and gender matched with patients undergoing craniotomy for intracranial tumor (IT), an internal control for comparison. Demographic and clinical data were collected to measure frailty, using the modified frailty index-11 (mFI-11) and pre-operative American Society of Anesthesiologists Physical Status Classification System (ASA). Post-operative complications were measured by the Clavien-Dindo Grade (CDG).

RESULTS

No significant difference in mFI-11 or ASA score was observed between the IA and IT groups (P=0.058 and P=0.131, respectively). IA patients had significantly higher CDG as compared with the control IT patients (P<0.001). There was a trend towards increasing LOS in the IA group as compared to the IT group (P=0.053). Increasing mFI and ASA were significant predictors of LOS by multiple linear regression in the IA group (P=0.006 and P=0.001, respectively), but not in the control IT group. Neither mFI-11 nor ASA were found to be predictors for CDG in either group. Within this case-control group of patients, we found an increase for odds of having IA with increasing mFI (OR=1.838, 95% CI: 1.016-3.362, P=0.044).

CONCLUSIONS

Frail IA patients tend to have more severe postoperative complications. The mFI-11 seems to predict increased resource utilization in the form of LOS. This study provides the initial retrospective data of another neurosurgical pathology where frailty leads to significantly worse outcomes. We also found that mFI may serve as a potential risk factor for severe disease.

Extreme-aged patients (≥ 85 years) experience similar outcomes as younger geriatric patients following chronic subdural hematoma evacuation: a matched cohort study

Subdural hematoma (SDH) evacuation represents one of the most frequently performed neurosurgical procedures. Several reports cite a rise in both the age and number of patient's requiring treatment, due in part to an aging population and expanded anticoagulation use. However, limited data and conflicting conclusions exist on extreme-aged geriatric patients (≥ 85 years of age) after undergoing surgery. Patients undergoing SDH evacuation at a tertiary academic medical center between November 2013-December 2021 were retrospectively identified. The study group consisted of patients ≥ 85 years (Group 1) diagnosed with a chronic SDH surgically evacuated. A control group was created matching patients by 70-84 years of age, gender, and anticoagulation use (Group 2). Multiple metrics were evaluated between the two including length-of hospital-stay, tracheostomy/PEG placement, reoperation rate, complications, discharge location, neurological outcome at the time of discharge, and survival. A total of 130 patients were included; 65 in Group 1 and 65 in Group 2. Patient demographics, medical comorbidities, SDH characteristics, international normalized ratio, partial thromboplastin time, and use of blood thinning agents were similar between the two groups. Kaplan Meier survival analysis at one-year was 80% for Group 1 and 76% for Group 2. No significant difference was identified using the log-rank test for equality of survivor functions (p = 0.26). All measured outcomes including GCS at time of discharge, length of stay, rate of reoperations, and neurological outcome were statistically similar between the two groups. Backwards stepwise conditional logistic regression revealed no significant association between poor outcomes at the time of discharge and age. Alternatively, anticoagulation use was found to be associated with poor outcomes (OR 3.55, 95% CI 1.08-11.60; p = 0.036). Several outcome metrics and statistical analyses were used to compare patients ≥ 85 years of age to younger geriatric patients (70-84 years) in a matched cohort study. Adjusting for age group, gender, and anticoagulation use, no significant difference was found between the two groups including neurological outcome at discharge, reoperation rate, and survival.

Frailty as a predictor of poor outcomes in patients with chronic subdural hematoma (cSDH): A systematic review of literature

Objective

In recent years, frailty has been reported to be an important predictive factor associated with worse outcomes in neurosurgical patients. The purpose of the present systematic review was to analyze the impact of frailty on outcomes of chronic subdural hematoma (cSDH) patients.

Methods

We performed a systematic review of literature using the PubMed, Cochrane library, Wiley online library, and Web of Science databases following PRISMA guidelines of studies evaluating the effect of frailty on outcomes of cSDH published until January 31, 2023.

Results

A comprehensive literature search of databases yielded a total of 471 studies. Six studies with 4085 patients were included in our final qualitative systematic review. We found that frailty was associated with inferior outcomes (including mortality, complications, recurrence, and discharge disposition) in cSDH patients. Despite varying frailty scales/indices used across studies, negative outcomes occurred more frequently in patients that were frail than those who were not.

Conclusions

While the small number of available studies, and heterogenous methodology and reporting parameters precluded us from conducting a pooled analysis, the results of the present systematic review identify frailty as a robust predictor of worse outcomes in cSDH patients. Future studies with a larger sample size and consistent frailty scales/indices are warranted to strengthen the available evidence. The results of this work suggest a strong case for using frailty as a pre-operative risk stratification measure in cSDH patients.

Risk Analysis Index and 30-Day Mortality after Brain Tumor Resection: A Multicenter Frailty Analysis of 31,776 Patients from 2012 to 2020

Introduction  The aim of this study was to evaluate the discriminative accuracy of the preoperative Risk Analysis Index (RAI) frailty score for prediction of mortality or transition to hospice within 30 days of brain tumor resection (BTR) in a large multicenter, international, prospective database. Methods  Records of BTR patients were extracted from the American College of Surgeons National Surgical Quality Improvement Program (2012-2020) database. The relationship between the RAI frailty scale and the primary end point (mortality or discharge to hospice within 30 days of surgery) was assessed using linear-by-linear proportional trend tests, logistic regression, and receiver operating characteristic (ROC) curve analysis (area under the curve as C-statistic). Results  Patients with BTR ( N  = 31,776) were stratified by RAI frailty tier: 16,800 robust (52.8%), 7,646 normal (24.1%), 6,593 frail (20.7%), and 737 severely frail (2.3%). The mortality/hospice rate was 2.5% ( n  = 803) and was positively associated with increasing RAI tier: robust (0.9%), normal (3.3%), frail (4.6%), and severely frail (14.2%) ( p  < 0.001). Isolated RAI was a robust discriminatory of primary end point in ROC curve analysis in the overall BTR cohort (C-statistic: 0.74; 95% confidence interval [CI]: 0.72-0.76) as well as the malignant (C-statistic: 0.74; 95% CI: 0. 67-0.80) and benign (C-statistic: 0.71; 95% CI: 0.70-0.73) tumor subsets (all p  < 0.001). RAI score had statistically significantly better performance compared with the 5-factor modified frailty index and chronological age (both p  < 0.0001). Conclusions  RAI frailty score predicts 30-day mortality after BTR and may be translated to the bedside with a user-friendly calculator ( https://nsgyfrailtyoutcomeslab.shinyapps.io/braintumormortalityRAIcalc/ ). The findings hope to augment the informed consent and surgical decision-making process in this patient population and provide an example for future study designs.

Frailty as a predictor of postoperative outcomes in neurosurgery: a systematic review

INTRODUCTION

Baseline frailty status has been utilized to predict a wide range of outcomes and guide preoperative decision making in neurosurgery. This systematic review aims to analyze existing literature on the utilization of frailty as a predictor of neurosurgical outcomes.

EVIDENCE ACQUISITION

We conducted a systematic review following PRISMA guidelines. Studies that utilized baseline frailty status to predict outcomes after a neurosurgical intervention were included in this systematic review. Studies that utilized sarcopenia as the sole measure of frailty were excluded. PubMed, EMBASE, and Cochrane library was searched from inception to March 1st, 2023, to identify relevant articles.

EVIDENCE SYNTHESIS

Overall, 244 studies met the inclusion criteria. The 11-factor modified frailty index (mFI-11) was the most utilized frailty measure (N.=91, 37.2%) followed by the five-factor modified Frailty Index (mFI-5) (N.=80, 32.7%). Spine surgery was the most common subspecialty (N.=131, 53.7%), followed by intracranial tumor resection (N.=57, 23.3%), and post-operative complications were the most reported outcome (N.=130, 53.2%) in neurosurgical frailty studies. The USA and the Bowers author group published the greatest number of articles within the study period (N.=176, 72.1% and N.=37, 15.2%, respectively).

CONCLUSIONS

Frailty literature has grown exponentially over the years and has been incorporated into neurosurgical decision making. Although a wide range of frailty indices exist, their utility may vary according to their ability to be incorporated in the outpatient clinical setting.

The Hospital Frailty Risk Score Independently Predicts Postoperative Outcomes in Glioblastoma Patients

OBJECTIVE

The Hospital Frailty Risk Score (HFRS) is a tool for quantifying patient frailty using International Classification of Diseases, Tenth Revision codes. This study aimed to determine the utility of the HFRS in predicting surgical outcomes after resection of glioblastoma (GBM) and compare its prognostic ability with other validated indices such as American Society of Anesthesiologists score and Charlson Comorbidity Index.

METHODS

A retrospective analysis was conducted using a GBM patient database (2017-2019) at a single institution. HFRS was calculated using International Classification of Diseases, Tenth Revision codes. Bivariate logistic regression was used to model prognostic ability of each frailty index, and model discrimination was assessed using area under the receiver operating characteristic curve. Multivariate linear and logistic regression models were used to assess for significant associations between HFRS and continuous and binary postoperative outcomes, respectively.

RESULTS

The study included 263 patients with GBM. The HFRS had a significantly greater area under the receiver operating characteristic curve compared with American Society of Anesthesiologists score (P = 0.016) and Charlson Comorbidity Index (P = 0.037) for predicting 30-day readmission. On multivariate analysis, the HFRS was significantly and independently associated with hospital length of stay (P = 0.0038), nonroutine discharge (P = 0.018), and 30-day readmission (P = 0.0051).

CONCLUSIONS

The HFRS has utility in predicting postoperative outcomes for patients with GBM and more effectively predicts 30-day readmission than other frailty indices. The HFRS may be used as a tool for optimizing clinical decision making to reduce adverse postoperative outcomes in patients with GBM.

Impact of Frailty on Postoperative Outcomes in Extended Endonasal Skull Base Surgery for Suprasellar Pathologies

OBJECTIVE

Frailty metrics estimate a patient's ability to tolerate physiologic stress and there are limited frailty data in patients undergoing expanded endonasal approaches (EEA) for suprasellar pathologies. Elevated frailty metrics have been associated with increased perioperative complications in patients undergoing craniotomies. We sought to examine this potential relationship in EEA.

STUDY DESIGN

Retrospective cohort study.

SETTING

Two tertiary academic skull base centers.

METHODS

Cases of patients undergoing EEA for suprasellar pathologies were reviewed. Demographic, treatment, survival, and postoperative outcomes data were recorded. Frailty was calculated using validated indexes, including the American Society of Anesthesiologists (ASA) classification, the modified 5-item frailty index (mFI-5), and the Charlson comorbidity index (CCI). Primary outcomes included 30-day medical and surgical complications.

RESULTS

A total of 88 patients were included, with 59 (67%) female patients and a mean age of 54 ± 15 years. The most common pathologies included 53 meningiomas (60.2%) and 21 craniopharyngiomas (23.9%). Most patients were ASA class 3 (54.5%) with mean mFI-5 0.82 ± 1.01 and CCI 4.18 ± 2.42. There was no association between increased frailty and 30-day medical or surgical outcomes (including postoperative cerebrospinal fluid leak), prolonged length of hospital stay, or mortality (all P > .05). Higher mFI-5 was associated with an increased risk for 30-day readmission (odds ratio: 2.35, 95% confidence Interval: 1.10-5.64, P = .04).

CONCLUSION

Despite the patient population being notably frail, we only identified an increased risk for 30-day readmission and observed no links with deteriorating surgical, medical, or mortality outcomes. This implies that conventional frailty metrics may not effectively align with EEA outcomes.

Explore the Role of Frailty as a Contributor to the Association Between AT(N) Profiles and Cognition in Alzheimer's Disease

Background

The relationship between Alzheimer's disease (AD)-related pathology and cognition was not exactly consistent.

Objective

To explore whether the association between AD pathology and cognition can be moderated by frailty.

Methods

We included 1711 participants from the Alzheimer's Disease Neuroimaging Initiative database. Levels of cerebrospinal fluid amyloid-β, p-tau, and t-tau were identified for AD-related pathology based on the amyloid-β/tau/neurodegeneration (AT[N]) framework. Frailty was measured using a modified Frailty Index-11 (mFI-11). Regression and interaction models were utilized to assess the relationship among frailty, AT(N) profiles, and cognition. Moderation models analyzed the correlation between AT(N) profiles and cognition across three frailty levels. All analyses were corrected for age, sex, education, and APOEɛ4 status.

Results

In this study, frailty (odds ratio [OR] = 1.71, p < 0.001) and AT(N) profiles (OR = 2.00, p < 0.001) were independently associated with cognitive status. The model fit was improved when frailty was added to the model examining the relationship between AT(N) profiles and cognition (p < 0.001). There was a significant interaction between frailty and AT(N) profiles in relation to cognitive status (OR = 1.12, pinteraction = 0.028). Comparable results were obtained when Mini-Mental State Examination scores were utilized as the measure of cognitive performance. The association between AT(N) profiles and cognition was stronger with the levels of frailty.

Conclusions

Frailty may diminish patients' resilience to AD pathology and accelerate cognitive decline resulting from abnormal AD-related pathology. In summary, frailty contributes to elucidating the relationship between AD-related pathology and cognitive impairment.

Frailty is a Predictor of Increased Readmissions and Increased Postoperative Complications After Elective Treatment of Unruptured Aneurysms

INTRODUCTION

Frailty is a state of decreased physiologic reserve associated with adverse treatment outcomes across surgical specialties. We sought to determine whether frailty affected patient outcomes after elective treatment (open microsurgical clipping or endovascular therapy [EVT]) of unruptured cerebral aneurysms (UCAs).

METHODS

The National Readmissions Database was queried from 2010 to 2014 to identify patients who had a known UCA and underwent elective clipping or EVT. Frailty was assessed using the Johns Hopkins Adjusted Clinical Groups frailty indicator tool. Multivariable exact logistic regression analyses were conducted to assess the associations between frailty and the primary outcome variables of 30- and 90-day readmissions, complications, length of stay (LOS), and patient disposition.

RESULTS

Of 18,483 patients who underwent elective treatment for UCAs, 358 (1.9%) met the criteria for frailty. After adjusting for patient- and hospital-based factors, frailty (30-day: odds ratio [OR], 1.55; 95% confidence interval [CI], 1.11-2.17; P = 0.01; 90-day: OR, 1.47; 95% CI, 1.05-2.06; P = 0.02) and clipping versus EVT (30-day: OR, 2.12; 95% CI, 1.85-2.43; P < 0.000; 90-day: OR, 1.80; 95% CI, 1.59-2.03; P < 0.0001) were associated with increased readmission rates. Furthermore, frailty was associated with an increased rate of complications (surgical: OR, 2.91; 95% CI, 2.27-3.72; P < 0.0001; neurological: OR, 3.04; 95% CI, 2.43-3.81; P < 0.0001; major: OR, 2.75; 95% CI, 1.96-3.84; P < 0.0001), increased LOSs (incidence rate ratio, 3.08; 95% CI, 2.59-3.66; P < 0.0001), and an increased rate of nonroutine disposition (OR, 3.94; 95% CI, 2.91-5.34; P < 0.0001).

CONCLUSIONS

Frailty was associated with an increased likelihood of 30- and 90-day readmissions after elective treatment of UCAs. Frailty was notably associated with several postoperative complications, longer LOSs, and nonroutine disposition in the treatment of UCAs.

Association Between Urbanicity and Outcomes Among Patients with Spinal Cord Ependymomas in the United States

BACKGROUND

Spinal cord ependymomas (SCEs) represent the most common intramedullary spinal cord tumors among adults. Research shows that access to neurosurgical care and patient outcomes can be greatly influenced by patient location. This study investigates the association between the outcomes of patients with SCE in metropolitan and nonmetropolitan areas.

METHODS

Cases of SCE between 2004 and 2019 were identified within the Central Brain Tumor Registry of the United States, a combined dataset including the Centers for Disease Control and Prevention's National Program of Cancer Registries and National Cancer Institute's Surveillance, Epidemiology, and End Results Program data. Multivariable logistic regression models were constructed to evaluate the association between urbanicity and SCE treatment, adjusted for age at diagnosis, sex, race and ethnicity. Survival data was available from 42 National Program of Cancer Registries (excluding Kansas and Minnesota, for which county data are unavailable), and Cox proportional hazard models were used to understand the effect of surgical treatment, county urbanicity, age at diagnosis, and the interaction effect between age at diagnosis and surgery, on the survival time of patients.

RESULTS

Overall, 7577 patients were identified, with 6454 (85%) residing in metropolitan and 1223 (15%) in nonmetropolitan counties. Metropolitan and nonmetropolitan counties had different age, sex, and race/ethnicity compositions; however, demographics were not associated with differences in the type of surgery received when stratified by urbanicity. Irrespective of metropolitan status, individuals who were American Indian/Alaska Native non-Hispanic and Hispanic (all races) were associated with reduced odds of receiving surgery. Individuals who were Black non-Hispanic and Hispanic were associated with increased odds of receiving comprehensive treatment. Diagnosis of SCE at later ages was linked with elevated mortality (hazard ratio = 4.85, P < 0.001). Gross total resection was associated with reduced risk of death (hazard ratio = 0.37, P = 0.004), and age did not interact with gross total resection to influence risk of death.

CONCLUSIONS

The relationship between patients' residential location and access to neurosurgical care is critical to ensuring equitable distribution of care. This study represents an important step in delineating areas of existing disparities.

Impact of Preoperative Frailty on Outcomes in Patients with Cervical Spondylotic Myelopathy Undergoing Anterior vs. Posterior Cervical Surgery

Introduction: Frailty has been shown to negatively influence patient outcomes across many disease processes, including in the cervical spondylotic myelopathy (CSM) population. The aim of this study was to assess the impact that frailty has on patients with CSM who undergo anterior cervical discectomy and fusion (ACDF) or posterior cervical decompression and fusion (PCDF). Materials and Methods: A retrospective cohort study was performed using the 2016-2019 national inpatient sample. Adult patients (≥18 years old) undergoing ACDF only or PCDF only for CSM were identified using ICD codes. The patients were categorized based on receipt of ACDF or PCDF and pre-operative frailty status using the 11-item modified frailty index (mFI-11): pre-Frail (mFI = 1), frail (mFI = 2), or severely frail (mFI ≥ 3). Patient demographics, comorbidities, operative characteristics, perioperative adverse events (AEs), and healthcare resource utilization were assessed. Multivariate logistic regression analyses were used to identify independent predictors of extended length of stay (LOS) and non-routine discharge (NRD). Results: A total of 37,990 patients were identified, of which 16,665 (43.9%) were in the pre-frail cohort, 12,985 (34.2%) were in the frail cohort, and 8340 (22.0%) were in the severely frail cohort. The prevalence of many comorbidities varied significantly between frailty cohorts. Across all three frailty cohorts, the incidence of AEs was greater in patients who underwent PCDF, with dysphagia being significantly more common in patients who underwent ACDF. Additionally, the rate of adverse events significantly increased between ACDF and PCDF with respect to increasing frailty (p < 0.001). Regarding healthcare resource utilization, LOS and rate of NRD were significantly greater in patients who underwent PCDF in all three frailty cohorts, with these metrics increasing with frailty in both ACDF and PCDF cohorts (LOS: p < 0.001); NRD: p < 0.001). On a multivariate analysis of patients who underwent ACDF, frailty and severe frailty were found to be independent predictors of extended LOS [(frail) OR: 1.39, p < 0.001; (severely frail) OR: 2.25, p < 0.001] and NRD [(frail) OR: 1.49, p < 0.001; (severely frail) OR: 2.22, p < 0.001]. Similarly, in patients who underwent PCDF, frailty and severe frailty were found to be independent predictors of extended LOS [(frail) OR: 1.58, p < 0.001; (severely frail) OR: 2.45, p < 0.001] and NRD [(frail) OR: 1.55, p < 0.001; (severely frail) OR: 1.63, p < 0.001]. Conclusions: Our study suggests that preoperative frailty may impact outcomes after surgical treatment for CSM, with more frail patients having greater health care utilization and a higher rate of adverse events. The patients undergoing PCDF ensued increased health care utilization, compared to ACDF, whereas severely frail patients undergoing PCDF tended to have the longest length of stay and highest rate of non-routine discharge. Additional prospective studies are necessary to directly compare ACDF and PCDF in frail patients with CSM.

Frailty Predicts Worse Pain Outcomes for Older TN Patients Treated with Microvascular Decompression

BACKGROUND

Trigeminal neuralgia (TN) is a debilitating orofacial pain disorder. Recent data from a national database suggest that microvascular decompression (MVD) in frail patients is associated with more postoperative complications. However, the long-term pain outcomes for frail TN patients are not known. We aimed to elucidate the relationship between frailty and long-term pain outcomes after MVD for TN.

METHODS

From 2007 to 2020, 368 TN patients aged ≥60 years underwent MVD at our institution. Patient demographics, clinical characteristics, postoperative complications, and long-term pain outcomes were recorded. Frailty was assessed using the modified 5-item frailty index (mFI-5) score, and the patients were dichotomized into nonfrail (mFI-5 <2) and frail (mFI-5 >1). Differences were assessed via the t test, χ2 test, multivariate ordinal regression, and Cox proportional hazards analysis.

RESULTS

Of the 368 patients analyzed, 9.8% were frail. The frail patients were significantly older (P = 0.02) with a higher body mass index (P = 0.01) and a greater incidence of comorbidities (P < 0.001). Frail patients presented with significantly higher pain levels at the final follow-up (P = 0.04). On multivariate analysis, frailty was independently associated with more pain at follow-up (P = 0.01), as was younger age, female sex, and black race. The relationship between frailty and postoperative pain recurrence showed a trend toward significance (P = 0.06), and younger age and black race were significantly associated with recurrence.

CONCLUSIONS

Frail patients undergoing MVD are at risk of worse long-term pain outcomes. Our results provide clinicians with useful information pertaining to the influence of frailty on the long-term efficacy of MVD in treating TN.

Frailty indices in patients undergoing surgical resection of brain metastases: a systematic review

Brain metastases are a relatively common occurrence in patients with primary malignancies, with an incidence ranging from 9 to 17%. Their prevalence has increased due to treatment advancements that have led to improved survival in cancer patients. Frailty has demonstrated the ability to outperform greater patient age in surgical decision-making by predicting postoperative adverse events that include mortality, extended length of hospital stay, non-routine discharge disposition, and postoperative complications. Although predictive models based on frailty have been increasingly utilized in literature, their generalizability remains questionable due to inadequacies in model development and validation. Our systematic review describes development and validation cohorts of frailty indices used in patients undergoing surgical resection of brain metastases and serves as a guide to their incorporation in the outpatient clinical setting. A systematic review of literature was performed using PubMed and Google Scholar. Articles that reported outcomes using frailty indices in patients undergoing surgical resection of brain metastases were included. The Newcastle Ottawa Scale (NOS) was used to assess for risk of bias across individual studies. Studies with NOS > 5 were considered high quality. We identified 238 articles through our search strategy. After a title and abstract screen, followed by a full text review, 9 articles met criteria for inclusion. The 5- and 11-factor modified frailty indices were most frequently utilized (n = 4). Five studies utilized single-hospital databases, and four utilized nationwide databases. Six studies were considered high-quality based on the NOS. Although frailty indices have demonstrated the ability to predict outcomes in patients undergoing surgical resection of brain metastases, further validation of these indices is necessary prior to their incorporation in clinical practice.

Frailty Indexes in Metastatic Spine Tumor Surgery: A Narrative Review

Quantification of preoperative frailty is an important prognostic tool in neurosurgical decision making. Metastatic spine tumor patients undergoing surgery are frail and have unfavorable outcomes that include an increased length of stay, unfavorable discharge disposition, and increased readmission rates. These undesirable outcomes result in higher treatment costs. A heterogeneous mixture of various frailty indexes is available with marked variance in their validation, leading to disparate clinical utility. The lack of a universally accepted definition for frailty, let alone in the method of creation or elements required in the formation of a frailty index, has resulted in a body of frailty literature lacking precision for predicting neurosurgical outcomes. In this review, we examine the role of reported frailty indexes in predicting postoperative outcomes after resection of metastatic spine tumors and aim to assist as a frailty guide for helping clinical decision making.

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.

Frailty Measured by the Risk Analysis Index Predicts Nonhome Discharge and Mortality After Resection in Refractory Epilepsy: Analysis of 1236 Patients From a Prospective Surgical Registry, 2012 to 2020

BACKGROUND

Risk stratification of epilepsy surgery patients remains difficult. The Risk Analysis Index (RAI) is a frailty measurement that augments preoperative risk stratification.

OBJECTIVE

To evaluate RAI's discriminative threshold for nonhome discharge disposition (NHD) and mortality (or discharge to hospice within 30 days of operation) in epilepsy surgery patients.

METHODS

Patients were queried from the American College of Surgeons-National Surgical Quality Improvement Program database (2012-2020) using diagnosis/procedure codes. Linear-by-linear trend tests assessed RAI's relationship with NHD and mortality. Discriminatory accuracy was assessed by C-statistics (95% CI) in receiver operating characteristic curve analysis.

RESULTS

Epilepsy resections (N = 1236) were grouped into temporal lobe (60.4%, N = 747) and nontemporal lobe (39.6%, N = 489) procedures. Patients were stratified by RAI tier: 76.5% robust (RAI 0-20), 16.2% normal (RAI 21-30), 6.6% frail (RAI 31-40), and 0.8% severely frail (RAI 41 and above). The NHD rate was 18.0% (N = 222) and positively associated with increasing RAI tier: 12.5% robust, 34.0% normal, 38.3% frail, and 50.0% severely frail ( P < .001). RAI had robust predictive discrimination for NHD in overall cohort (C-statistic 0.71), temporal lobe (C-statistic 0.70), and nontemporal lobe (C-statistic 0.71) cohorts. The mortality rate was 2.7% (N = 33) and significantly associated with RAI frailty: 1.1% robust, 8.0% normal, 6.2% frail, and 20.0% severely frail ( P < .001). RAI had excellent predictive discrimination for mortality in overall cohort (C-statistic 0.78), temporal lobe (C-statistic 0.80), and nontemporal lobe (C-statistic 0.74) cohorts.

CONCLUSION

The RAI frailty score predicts mortality and NHD after epilepsy surgery. This is accomplished with a user-friendly calculator: https://nsgyfrailtyoutcomeslab.shinyapps.io/epilepsy/ .

A comparative analysis of the Hospital Frailty Risk Score in predicting postoperative outcomes among intracranial tumor patients

OBJECTIVE

In recent years, frailty indices such as the 11- and 5-factor modified frailty indices (mFI-11 and mFI-5), American Society of Anesthesiologists (ASA) physical status classification, and Charlson Comorbidity Index (CCI) have been shown to be effective predictors of various postoperative outcomes in neurosurgical patients. The Hospital Frailty Risk Score (HFRS) is a well-validated tool for assessing frailty; however, its utility has not been evaluated in intracranial tumor surgery. In the present study, the authors investigated the accuracy of the HFRS in predicting outcomes following intracranial tumor resection and compared its utility to those of other validated frailty indices.

METHODS

A retrospective analysis was conducted using an intracranial tumor patient database at a single institution. Patients eligible for study inclusion were those who had undergone resection for an intracranial tumor between January 1, 2017, and December 31, 2019. ICD-10 codes were used to identify HFRS components and subsequently calculate risk scores. In addition to several postoperative variables, ASA class, CCI, and mFI-11 and mFI-5 scores were determined for each patient. Model discrimination was assessed using the area under the receiver operating characteristic curve (AUROC), and the DeLong test was used to assess for significant differences between AUROCs. Multivariate models for continuous outcomes were constructed using linear regression, whereas logistic regression models were used for categorical outcomes.

RESULTS

A total of 2518 intracranial tumor patients (mean age 55.3 ± 15.1 years, 53.4% female, 70.4% White) were included in this study. The HFRS had a statistically significant greater AUROC than ASA status, CCI, mFI-11, and mFI-5 for postoperative complications, high hospital charges, nonroutine discharge, and 90-day readmission. In the multivariate analysis, the HFRS was significantly and independently associated with postoperative complications (OR 1.14, p < 0.0001), hospital length of stay (coefficient = 0.50, p < 0.0001), high hospital charges (coefficient = 1917.49, p < 0.0001), nonroutine discharge (OR 1.14, p < 0.0001), and 90-day readmission (OR 1.06, p < 0.0001).

CONCLUSIONS

The study findings suggest that the HFRS is an effective predictor of postoperative outcomes in intracranial tumor patients and more effectively predicts adverse outcomes than other frailty indices. The HFRS may serve as an important tool for reducing patient morbidity and mortality in intracranial tumor surgery.

Assessment of the impact of frailty on adverse surgical outcomes in patients undergoing surgery for intracranial tumors using modified frailty index: A systematic review and meta-analysis

BACKGROUND

Modified frailty index (MFI) is an emerging quantitative measure of frailty; however, the quantified risk of adverse outcomes in surgeries for intracranial tumors associated with increasing MFI scores has not been thoroughly reviewed in a comprehensive manner.

METHODS

MEDLINE (PubMed), Scopus, Web of Science, and Embase were searched to identify observational studies on the association between 5 and 11 item-modified frailty index (MFI) and perioperative outcomes for neurosurgical procedures including complications, mortality, readmission, and reoperation rate. Primary analysis pooled all comparisons with MFI scores greater than or equal to 1 versus non-frail participants using mixed-effects multilevel model for each outcome.

RESULTS

In total, 24 studies were included in the review and 19 studies with 114,707 surgical operations were included in the meta-analysis. While increasing MFI scores were associated with worse prognosis for all included outcomes, reoperation rate was only significantly higher in patients with MFI ≥ 3. Among surgical pathologies, glioblastoma was influenced by a greater extent to the impact of frailty on complications and mortality that most other etiologies. In agreement with qualitative evaluation of the included studies, meta-regression did not reveal association between mean age of the comparisons and complications rate.

CONCLUSION

The results of this meta-analysis provides quantitative risk assessment of adverse outcomes in neuro-oncological surgeries with increased frailty. The majority of literature suggests that MFI is a superior and independent predictor of adverse outcomes compared to age.

Baseline frailty status, not advanced patient age, predicts epilepsy surgery outcomes: An analysis of 696 patients from the NSQIP database

OBJECTIVE

Preoperative risk stratification of patients undergoing epilepsy surgery remains challenging. Recently, the efforts to look beyond age alone as an outcomes predictor has resulted in the development of measures of physiological reserve, or 'frailty indices.' The most frequently cited index in neurosurgery is the 11-item or 5-item modified frailty index (mFI11 or mFI-5). The present study aimed to use a large national registry to evaluate the effect of frailty (as measured by mFI-5 versus age on postoperative outcomes of patients undergoing epilepsy surgery.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database, overseen by the American College of Surgeons (ACS), was used to extract data for patients undergoing epilepsy surgery from 2015 to 2019. Univariate and multivariate analyses for age and mFI-5 were performed for the following 30-day outcomes of extended length of hospital stay (eLOS) and non-home discharge (NHD). The effect sizes were summarized by odds ratio and associated 95 % confidence intervals. Receiver operating characteristic (ROC) curve analysis, including area under the curve (AUC), was used to quantify the discrimination.

RESULTS

Univariate and multivariate analyses demonstrated that frailty statuses from mFI-5, not age, were significantly predictive of eLOS and NHD. On ROC curve analysis, mFI-5 was a stronger predictor of eLOS (C = 0.59, 95 % CI 0.54-0.64, p < 0.001) and NHD (C = 0.69, 95 % CI 0.64-0.76, p < 0.001) than age (C = 0.53, 95 % CI 0.48-0.58, p = 0.21 and C = 0.53, 95 % CI 0.46-0.59, p = 0.44, respectively).

CONCLUSION

Frailty, not age, is an independent risk factor for poor postoperative outcomes, particularly eLOS and NHD, in patients undergoing epilepsy surgery. Usage of mFI-5 for preoperative risk stratification of epilepsy surgery patients can help in prognostication.

Benchmarking short-term postoperative mortality across neurosurgery units: is hospital administrative data good enough for risk-adjustment?

BACKGROUND

Surgical mortality indicators should be risk-adjusted when evaluating the performance of organisations. This study evaluated the performance of risk-adjustment models that used English hospital administrative data for 30-day mortality after neurosurgery.

METHODS

This retrospective cohort study used Hospital Episode Statistics (HES) data from 1 April 2013 to 31 March 2018. Organisational-level 30-day mortality was calculated for selected subspecialties (neuro-oncology, neurovascular and trauma neurosurgery) and the overall cohort. Risk adjustment models were developed using multivariable logistic regression and incorporated various patient variables: age, sex, admission method, social deprivation, comorbidity and frailty indices. Performance was assessed in terms of discrimination and calibration.

RESULTS

The cohort included 49,044 patients. Overall, 30-day mortality rate was 4.9%, with unadjusted organisational rates ranging from 3.2 to 9.3%. The variables in the best performing models varied for the subspecialties; for trauma neurosurgery, a model that included deprivation and frailty had the best calibration, while for neuro-oncology a model with these variables plus comorbidity performed best. For neurovascular surgery, a simple model of age, sex and admission method performed best. Levels of discrimination varied for the subspecialties (range: 0.583 for trauma and 0.740 for neurovascular). The models were generally well calibrated. Application of the models to the organisation figures produced an average (median) absolute change in mortality of 0.33% (interquartile range (IQR) 0.15-0.72) for the overall cohort model. Median changes for the subspecialty models were 0.29% (neuro-oncology, IQR 0.15-0.42), 0.40% (neurovascular, IQR 0.24-0.78) and 0.49% (trauma neurosurgery, IQR 0.23-1.68).

CONCLUSIONS

Reasonable risk-adjustment models for 30-day mortality after neurosurgery procedures were possible using variables from HES, although the models for trauma neurosurgery performed less well. Including a measure of frailty often improved model performance.

Hospital-acquired infection following spinal tumor surgery: A frailty-driven pre-operative risk model

BACKGROUND

Hospital-acquired infection (HAI) after spinal tumor resection surgery contributes to adverse patient outcomes and excess healthcare resource utilization. This study sought to develop a predictive model for HAI occurrence following surgery for spinal tumors.

METHODS

The National Surgical Quality Improvement Program (NSQIP) 2015-2019 database was queried for spinal tumor resections. Baseline demographics and preoperative clinical characteristics, including frailty, were analyzed. Frailty was measured by modified frailty score 5 (mFI-5) and risk analysis index (RAI). Univariate and multivariable analyses were performed to identify independent risk factors for HAI occurrence. A logit-based predictive model for HAI occurrence was designed and discriminative power was assessed via receiver operating characteristic (ROC) analysis.

RESULTS

Of 5883 patients undergoing spinal tumor surgery, HAI occurred in 574 (9.8 %). The HAI (vs. non-HAI) cohort was older and frailer with higher rates of preoperative functional dependence, chronic steroid use, chronic lung disease, coagulopathy, diabetes, hypertension, tobacco smoking, unintentional weight loss, and hypoalbuminemia (all P < 0.05). In multivariable analysis, independent predictors of HAI occurrence included severe frailty (mFI-5, OR: 2.3, 95 % CI: 1.1-5.2, P = 0.035), nonelective surgery (OR: 1.7, 95 % CI: 1.1-2.4, P = 0.007), and hypoalbuminemia (OR: 1.5, 95 % CI: 1.1-2.2, P = 0.027). A logistic regression model with frailty score alongside age, race, BMI, elective vs. non-elective surgery, and pre-operative labs have predicted HAI occurrence with a C-statistic of 0.68 (95 % CI: 0.64-0.72).

CONCLUSIONS

HAI occurrence after spinal tumor surgery can be predicted by standardized frailty metrics, mFI-5 and RAI-rev, alongside routinely measured preoperative characteristics (demographics, comorbidities, pre-operative labs).

The Additional Economic Burden of Frailty in Adult Cervical Deformity Patients Undergoing Surgical Intervention

SUMMARY OF BACKGROUND DATA

The influence of frailty on economic burden following corrective surgery for the adult cervical deformity (CD) is understudied and may provide valuable insights for preoperative planning.

OBJECTIVE

To assess the influence of baseline frailty status on the economic burden of CD surgery.

STUDY DESIGN

Retrospective cohort.

MATERIALS AND METHODS

CD patients with frailty scores and baseline and two-year Neck Disability Index data were included. Frailty score was categorized patients by modified CD frailty index into not frail (NF) and frail (F). Analysis of covariance was used to estimate marginal means adjusting for age, sex, surgical approach, and baseline sacral slope, T1 slope minus cervical lordosis, C2-C7 angle, C2-C7 sagittal vertical axis. Costs were derived from PearlDiver registry data. Reimbursement consisted of a standardized estimate using regression analysis of Medicare payscales for services within a 30-day window including length of stay and death. This data is representative of the national average Medicare cost differentiated by complication/comorbidity outcome, surgical approach, and revision status. Cost per quality-adjusted life-year (QALY) at two years was calculated for NF and F patients.

RESULTS

There were 126 patients included. There were 68 NF patients and 58 classified as F. Frailty groups did not differ by overall complications, instance of distal junctional kyphosis, or reoperations (all P >0.05). These groups had similar rates of radiographic and clinical improvement by two years. NF and F had similar overall cost ($36,731.03 vs. $37,356.75, P =0.793), resulting in equivocal costs per QALYs for both patients at two years ($90,113.79 vs. $80,866.66, P =0.097).

CONCLUSION

F and NF patients experienced similar complication rates and upfront costs, with equivocal utility gained, leading to comparative cost-effectiveness with NF patients based on cost per QALYs at two years. Surgical correction for CD is an economical healthcare investment for F patients when accounting for anticipated utility gained and cost-effectiveness following the procedure.

LEVEL OF EVIDENCE

III.

Frailty in Patients Undergoing Surgery for Brain Tumors: A Systematic Review of the Literature

BACKGROUND

Emerging literature suggests that frailty may be an important driver of postoperative outcomes in patients undergoing surgery for brain tumors. We systematically reviewed the literature on frailty in patients with brain tumor with respect to 3 questions: What methods of frailty assessment have been applied to patients with brain tumor? What thresholds have been defined to distinguish between different levels of frailty? What clinical outcomes does frailty predict in patients with brain tumor?

METHODS

A literature search was conducted using PubMed, Embase, The Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov. Included studies were specific to patients with brain tumor, used a validated instrument to assess frailty, and measured the impact of frailty on postoperative outcomes.

RESULTS

Of 753 citations, 21 studies met our inclusion criteria. Frailty instruments were studied, in order of frequency reported, including the 5-factor modified frailty index, 11-factor modified frailty index, Johns Hopkins Adjusted Clinical Groups frailty-defining diagnosis indicator, and Hopkins Frailty Score. Multiple different conventions and thresholds were reported for distinguishing the levels of frailty. Clinical outcomes associated with frailty included mortality, survival, complications, length of stay, charges, costs, discharge disposition, readmissions, and operative time.

CONCLUSIONS

Frailty is an increasingly popular concept in patients with brain tumor that is associated with important clinical outcomes. However, the extant literature is largely comprised of retrospective studies with heterogeneous definitions of frailty, thresholds for defining levels of frailty, and patient populations. Further work is needed to understand best practices in assessing frailty in patients with brain tumor and applying these concepts to clinical practice.

Frailty Is Superior to Age for Predicting Readmission, Prolonged Length of Stay, and Wound Infection in Elective Otology Procedures

OBJECTIVE

To determine the predictive ability of the 5-point modified frailty index relative to age in elective otology patients.

STUDY DESIGN

Retrospective database analysis.

SETTING

Multicenter, national database of surgical patients.

PATIENTS

We selected all elective surgical patients who received tympanoplasty, tympanomastoidectomy, mastoidectomy, revision mastoidectomy, and cochlear implant procedures from 2016 to 2019 from the National Surgical Quality Improvement database.

INTERVENTIONS

Therapeutic.

MAIN OUTCOME MEASURES

Readmission rates, discharge disposition, reoperation rates, and extended length of hospital stay.

RESULTS

Utilizing receiver operating characteristics with area under the curve (AUC) analysis, nonrobust status was determined to be a superior predictor relative to age of readmission (AUC = 0.628 [p < 0.001] versus AUC = 0.567 [p = 0.047], respectively) and open wound infection relative to age (AUC = 0.636 [p = 0.024] versus AUC = 0.619 [p = 0.048], respectively). Nonrobust otology patients were more likely to have dyspnea at rest and an American Society of Anesthesiology score higher than 2 before surgery (odds ratios, 13.304 [95% confidence interval, 2.947-60.056; p < 0.001] and 7.841 [95% confidence interval, 7.064-8.704; p < 0.001], respectively).

CONCLUSION

Nonrobust status was found to be a useful predictor of readmission and prolonged length of stay in patients undergoing elective otology procedures, which generally have low complication rate. Given the aging population and corresponding increase in otology disease, it is important to use age-independent risk stratification measures. Frailty may provide a useful risk stratification tool to select surgical candidates within the aging population.

Evaluating frailty, mortality, and complications associated with metastatic spine tumor surgery using machine learning-derived body composition analysis

OBJECTIVE

Cancer patients with spinal metastases may undergo surgery without clear assessments of prognosis, thereby impacting the optimal palliative strategy. Because the morbidity of surgery may adversely impact recovery and initiation of adjuvant therapies, evaluation of risk factors associated with mortality risk and complications is critical. Evaluation of body composition of cancer patients as a surrogate for frailty is an emerging area of study for improving preoperative risk stratification.

METHODS

To examine the associations of muscle characteristics and adiposity with postoperative complications, length of stay, and mortality in patients with spinal metastases, the authors designed an observational study of 484 cancer patients who received surgical treatment for spinal metastases between 2010 and 2019. Sarcopenia, muscle radiodensity, visceral adiposity, and subcutaneous adiposity were assessed on routinely available 3-month preoperative CT images by using a validated deep learning methodology. The authors used k-means clustering analysis to identify patients with similar body composition characteristics. Regression models were used to examine the associations of sarcopenia, frailty, and clusters with the outcomes of interest.

RESULTS

Of 484 patients enrolled, 303 had evaluable CT data on muscle and adiposity (mean age 62.00 ± 11.91 years; 57.8% male). The authors identified 2 clusters with significantly different body composition characteristics and mortality risks after spine metastases surgery. Patients in cluster 2 (high-risk cluster) had lower muscle mass index (mean ± SD 41.16 ± 7.99 vs 50.13 ± 10.45 cm2/m2), lower subcutaneous fat area (147.62 ± 57.80 vs 289.83 ± 109.31 cm2), lower visceral fat area (82.28 ± 48.96 vs 239.26 ± 98.40 cm2), higher muscle radiodensity (35.67 ± 9.94 vs 31.13 ± 9.07 Hounsfield units [HU]), and significantly higher risk of 1-year mortality (adjusted HR 1.45, 95% CI 1.05-2.01, p = 0.02) than individuals in cluster 1 (low-risk cluster). Decreased muscle mass, muscle radiodensity, and adiposity were not associated with a higher rate of complications after surgery. Prolonged length of stay (> 7 days) was associated with low muscle radiodensity (mean 30.87 vs 35.23 HU, 95% CI 1.98-6.73, p < 0.001).

CONCLUSIONS

Body composition analysis shows promise for better risk stratification of patients with spinal metastases under consideration for surgery. Those with lower muscle mass and subcutaneous and visceral adiposity are at greater risk for inferior outcomes.

Patient frailty association with cerebral arteriovenous malformation microsurgical outcomes and development of custom risk stratification score: an analysis of 16,721 nationwide admissions

OBJECTIVE

Patient frailty is associated with poorer perioperative outcomes for several neurosurgical procedures. However, comparative accuracy between different frailty metrics for cerebral arteriovenous malformation (AVM) outcomes is poorly understood and existing frailty metrics studied in the literature are constrained by poor specificity to neurosurgery. This aim of this paper was to compare the predictive ability of 3 frailty scores for AVM microsurgical admissions and generate a custom risk stratification score.

METHODS

All adult AVM microsurgical admissions in the National (Nationwide) Inpatient Sample (2002–2017) were identified. Three frailty measures were analyzed: 5-factor modified frailty index (mFI-5; range 0–5), 11-factor modified frailty index (mFI-11; range 0–11), and Charlson Comorbidity Index (CCI) (range 0–29). Receiver operating characteristic curves were used to compare accuracy between metrics. The analyzed endpoints included in-hospital mortality, routine discharge, complications, length of stay (LOS), and hospitalization costs. Survey-weighted multivariate regression assessed frailty-outcome associations, adjusting for 13 confounders, including patient demographics, hospital characteristics, rupture status, hydrocephalus, epilepsy, and treatment modality. Subsequently, k-fold cross-validation and Akaike information criterion–based model selection were used to generate a custom 5-variable risk stratification score called the AVM-5. This score was validated in the main study population and a pseudoprospective cohort (2018–2019).

RESULTS

The authors analyzed 16,271 total AVM microsurgical admissions nationwide, with 21.0% being ruptured. The mFI-5, mFI-11, and CCI were all predictive of lower rates of routine discharge disposition, increased perioperative complications, and longer LOS (all p < 0.001). Their AVM-5 risk stratification score was calculated from 5 variables: age, hydrocephalus, paralysis, diabetes, and hypertension. The AVM-5 was predictive of decreased rates of routine hospital discharge (OR 0.26, p < 0.001) and increased perioperative complications (OR 2.42, p < 0.001), postoperative LOS (+49%, p < 0.001), total LOS (+47%, p < 0.001), and hospitalization costs (+22%, p < 0.001). This score outperformed age, mFI-5, mFI-11, and CCI for both ruptured and unruptured AVMs (area under the curve [AUC] 0.78, all p < 0.001). In a pseudoprospective cohort of 2005 admissions from 2018 to 2019, the AVM-5 remained significantly associated with all outcomes except for mortality and exhibited higher accuracy than all 3 earlier scores (AUC 0.79, all p < 0.001).

CONCLUSIONS

Patient frailty is predictive of poorer disposition and elevated complications, LOS, and costs for AVM microsurgical admissions. The authors’ custom AVM-5 risk score outperformed age, mFI-5, mFI-11, and CCI while using threefold less variables than the CCI. This score may complement existing AVM grading scales for optimization of surgical candidates and identification of patients at risk of postoperative medical and surgical morbidity.

The role of frailty in the clinical management of neurofibromatosis type 1: a mixed-effects modeling study using the Nationwide Readmissions Database

OBJECTIVE

Frailty embodies a state of increased medical vulnerability that is most often secondary to age-associated decline. Recent literature has highlighted the role of frailty and its association with significantly higher rates of morbidity and mortality in patients with CNS neoplasms. There is a paucity of research regarding the effects of frailty as it relates to neurocutaneous disorders, namely, neurofibromatosis type 1 (NF1). In this study, the authors evaluated the role of frailty in patients with NF1 and compared its predictive usefulness against the Elixhauser Comorbidity Index (ECI).

METHODS

Publicly available 2016–2017 data from the Nationwide Readmissions Database was used to identify patients with a diagnosis of NF1 who underwent neurosurgical resection of an intracranial tumor. Patient frailty was queried using the Johns Hopkins Adjusted Clinical Groups frailty-defining indicator. ECI scores were collected in patients for quantitative measurement of comorbidities. Propensity score matching was performed for age, sex, ECI, insurance type, and median income by zip code, which yielded 60 frail and 60 nonfrail patients. Receiver operating characteristic (ROC) curves were created for complications, including mortality, nonroutine discharge, financial costs, length of stay (LOS), and readmissions while using comorbidity indices as predictor values. The area under the curve (AUC) of each ROC served as a proxy for model performance.

RESULTS

After propensity matching of the groups, frail patients had an increased mean ± SD hospital cost ($85,441.67 ± $59,201.09) compared with nonfrail patients ($49,321.77 ± $50,705.80) (p = 0.010). Similar trends were also found in LOS between frail (23.1 ± 14.2 days) and nonfrail (10.7 ± 10.5 days) patients (p = 0.0020). For each complication of interest, ROC curves revealed that frailty scores, ECI scores, and a combination of frailty+ECI were similarly accurate predictors of variables (p > 0.05). Frailty+ECI (AUC 0.929) outperformed using only ECI for the variable of increased LOS (AUC 0.833) (p = 0.013). When considering 1-year readmission, frailty (AUC 0.642) was outperformed by both models using ECI (AUC 0.725, p = 0.039) and frailty+ECI (AUC 0.734, p = 0.038).

CONCLUSIONS

These findings suggest that frailty and ECI are useful in predicting key complications, including mortality, nonroutine discharge, readmission, LOS, and higher costs in NF1 patients undergoing intracranial tumor resection. Consideration of a patient’s frailty status is pertinent to guide appropriate inpatient management as well as resource allocation and discharge planning.

The Clinical Frailty Scale as predictor of overall survival after resection of high-grade glioma

BACKGROUND

The Clinical Frailty Scale (CFS) describes the general level of fitness or frailty and is widely used in geriatric medicine, intensive care and orthopaedic surgery. This study was conducted to analyze, whether CFS could be used for patients with high-grade glioma.

METHODS

Patients harboring high-grade gliomas, undergoing first resection at our center between 2015 and 2020 were retrospectively evaluated. Patients' performance was assessed using the Rockwood Clinical Frailty Scale and the Karnofsky Performance Scale (KPS) preoperatively and 3-6 months postoperatively.

RESULTS

289 patients were included. Pre- as well as postoperative median frailty was 3 CFS points (IqR 2-4) corresponding to "managing well". CFS strongly correlated with KPS preoperatively (r = - 0.85; p < 0.001) and at the 3-6 months follow-up (r = - 0.90; p < 0.001). The reduction of overall survival (OS) was 54% per point of CFS preoperatively (HR 1.54, CI 95% 1.38-1.70; p < 0.001) and 58% at the follow-up (HR 1.58, CI 95% 1.41-1.78; p < 0.001), comparable to KPS. Patients with IDH mutation showed significantly better preoperative and follow-up CFS and KPS (p < 0.05). Age and performance scores correlated only mildly with each other (r = 0.21…0.35; p < 0.01), but independently predicted OS (p < 0.001 each).

CONCLUSION

CFS seems to be a reliable tool for functional assessment of patients suffering from high-grade glioma. CFS includes non-cancer related aspects and therefore is a contemporary approach for patient evaluation. Its projection of survival can be equally estimated before and after surgery. IDH-mutation caused longer survival and higher functionality.

Acute traumatic brain injury in frail patients: the next pandemic

PURPOSE OF REVIEW

To highlight recent findings on the evaluation and impact of frailty in the management of patients with traumatic brain injury (TBI).

RECENT FINDINGS

Frailty is not a direct natural consequence of aging. Rather, it commonly results from the intersection of age-related decline with chronic diseases and conditions. It is associated with adverse outcomes such as institutionalization, falls, and worsening health status. Growing evidence suggests that frailty should be a key consideration both in care planning and in adverse outcome prevention. The prevalence of elderly patients with TBI is increasing, and low-energy trauma (i.e., ground or low-level falls, which are typical in frail patients) is the major cause. Establishing the real incidence of frailty in TBI requires further studies. Failure to detect frailty potentially exposes patients to interventions that may not benefit them, and may even harm them. Moreover, considering patients as 'nonfrail' purely on the basis of their age is unacceptable. The future challenge is to shift to a new clinical paradigm characterized by more appropriate, goal-directed care of frail patients.

SUMMARY

The current review highlights the crucial importance of frailty evaluation in TBI, also given the changing epidemiology of this condition. To ensure adequate assessment, prevention and management, both in and outside hospital, there is an urgent need for a valid screening tool and a specific frailty-based and comorbidity-based clinical approach.

Frailty Status Is a More Robust Predictor Than Age of Spinal Tumor Surgery Outcomes: A NSQIP Analysis of 4,662 Patients

Objective

The present study aimed to evaluate the effect of baseline frailty status (as measured by modified frailty index-5 [mFI-5]) versus age on postoperative outcomes of patients undergoing surgery for spinal tumors using data from a large national registry.

Methods

The National Surgical Quality Improvement Program database was used to collect spinal tumor resection patients’ data from 2015 to 2019 (n = 4,662). Univariate and multivariate analyses for age and mFI-5 were performed for the following outcomes: 30-day mortality, major complications, unplanned reoperation, unplanned readmission, hospital length of stay (LOS), and discharge to a nonhome destination. Receiver operating characteristic (ROC) curve analysis was used to evaluate the discriminative performance of age versus mFI-5.

Results

Both univariate and multivariate analyses demonstrated that mFI-5 was a more robust predictor of worse postoperative outcomes as compared to age. Furthermore, based on categorical analysis of frailty tiers, increasing frailty was significantly associated with increased risk of adverse outcomes. ‘Severely frail’ patients were found to have the highest risk, with odds ratio 16.4 (95% confidence interval [CI],11.21–35.44) for 30-day mortality, 3.02 (95% CI, 1.97–4.56) for major complications, and 2.94 (95% CI, 2.32–4.21) for LOS. In ROC curve analysis, mFI-5 score (area under the curve [AUC] = 0.743) achieved superior discrimination compared to age (AUC = 0.594) for mortality.

Conclusion

Increasing frailty, as measured by mFI-5, is a more robust predictor as compared to age, for poor postoperative outcomes in spinal tumor surgery patients. The mFI-5 may be clinically used for preoperative risk stratification of spinal tumor patients.

Comparative associations of baseline frailty status and age with postoperative mortality and duration of hospital stay following metastatic brain tumor resection

Metastatic brain tumors are the most common intracranial neoplasms diagnosed in the United States. Although baseline frailty status has been validated as a robust predictor of morbidity and mortality across various surgical disciplines, evidence within cranial neurosurgical oncology is limited. Adult metastatic brain tumor patients treated with resection were identified in the National Inpatient Sample during the period of 2015-2018. Frailty was quantified using the 11-point modified frailty index (mFI-11) and its association with clinical endpoints was evaluated through complex samples multivariable logistic regression and receiver operating characteristic (ROC) curve analyses. Among 13,650 metastatic brain tumor patients identified (mean age 62.8 years), 26.8% (n = 3665) were robust (mFI = 0), 31.4% (n = 4660) were pre-frail (mFI = 1), 23.2% (n = 3165) were frail (mFI = 2), and 15.8% (n = 2160) were severely frail (mFI ≥ 3). On univariable assessment, these cohorts stratified by increasing frailty were significantly associated with postoperative complications (13.6%, 15.9%, 23.9%, 26.4%; p < 0.001), mortality (1.2%, 1.4%, 2.7%, 3.2%; p = 0.028), and extended length of stay (eLOS) (15.7%, 22.5%, 28.9%, 37.7%; p < 0.001). Following multivariable logistic regression analysis, frailty (by mFI-11) was independently associated with postoperative mortality (aOR 1.34, 95% CI 1.08, 1.65) and eLOS (aOR 1.26, 95% CI 1.17, 1.37), while increasing age was not associated with these endpoints. ROC curve analysis demonstrated superior discrimination of frailty (by mFI-11) in comparison with age for both mortality (AUC 0.61 vs. 0.58) and eLOS (AUC 0.61 vs. 0.53). Further statistical assessment through propensity score adjustment and decision tree analysis confirmed and extended the findings of the primary analytical models. Frailty may be a more robust predictor of postoperative outcomes in comparison with age following metastatic brain tumor resection.

Is Frailty Associated with Adverse Outcomes After Orthopaedic Surgery?: A Systematic Review and Assessment of Definitions

BACKGROUND

There is increasing evidence supporting the association between frailty and adverse outcomes after surgery. There is, however, no consensus on how frailty should be assessed and used to inform treatment. In this review, we aimed to synthesize the current literature on the use of frailty as a predictor of adverse outcomes following orthopaedic surgery by (1) identifying the frailty instruments used and (2) evaluating the strength of the association between frailty and adverse outcomes after orthopaedic surgery.

METHODS

A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, Scopus, and the Cochrane Central Register of Controlled Trials were searched to identify articles that reported on outcomes after orthopaedic surgery within frail populations. Only studies that defined frail patients using a frailty instrument were included. The methodological quality of studies was assessed using the Newcastle-Ottawa Scale (NOS). Study demographic information, frailty instrument information (e.g., number of items, domains included), and clinical outcome measures (including mortality, readmissions, and length of stay) were collected and reported.

RESULTS

The initial search yielded 630 articles. Of these, 177 articles underwent full-text review; 82 articles were ultimately included and analyzed. The modified frailty index (mFI) was the most commonly used frailty instrument (38% of the studies used the mFI-11 [11-item mFI], and 24% of the studies used the mFI-5 [5-item mFI]), although a large variety of instruments were used (24 different instruments identified). Total joint arthroplasty (22%), hip fracture management (17%), and adult spinal deformity management (15%) were the most frequently studied procedures. Complications (71%) and mortality (51%) were the most frequently reported outcomes; 17% of studies reported on a functional outcome.

CONCLUSIONS

There is no consensus on the best approach to defining frailty among orthopaedic surgery patients, although instruments based on the accumulation-of-deficits model (such as the mFI) were the most common. Frailty was highly associated with adverse outcomes, but the majority of the studies were retrospective and did not identify frailty prospectively in a prediction model. Although many outcomes were described (complications and mortality being the most common), there was a considerable amount of heterogeneity in measurement strategy and subsequent strength of association. Future investigations evaluating the association between frailty and orthopaedic surgical outcomes should focus on prospective study designs, long-term outcomes, and assessments of patient-reported outcomes and/or functional recovery scores.

CLINICAL RELEVANCE

Preoperatively identifying high-risk orthopaedic surgery patients through frailty instruments has the potential to improve patient outcomes. Frailty screenings can create opportunities for targeted intervention efforts and guide patient-provider decision-making.

The Impact of Multimorbidity Burden, Frailty Risk Scoring, and 3-Directional Morphological Indices vs. Testing for CSF Responsiveness in Normal Pressure Hydrocephalus

Objective: Multimorbidity burden across disease cohorts and variations in clinico-radiographic presentations within normal pressure hydrocephalus (NPH) confound its diagnosis, and the assessment of its amenability to interventions. We hypothesized that novel imaging techniques such as 3-directional linear morphological indices could help in distinguishing between hydrocephalus vs. non-hydrocephalus and correlate with responsiveness to external lumbar drainage (CSF responsiveness) within NPH subtypes.

Methodology: Twenty-one participants with NPH were recruited and age-matched to 21 patients with Alzheimer’s Disease (AD) and 21 healthy controls (HC) selected from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. Patients with NPH underwent testing via the NPH programme with external lumbar drainage (ELD); pre- and post-ELD MRI scans were obtained. The modified Frailty Index (mFI-11) was used to stratify the NPH cohort, including Classic and Complex subtypes, by their comorbidity and frailty risks. The quantitative imaging network tool 3D Slicer was used to derive traditional 2-dimensional (2d) linear measures; Evans Index (EI), Bicaudate Index (BCI) and Callosal Angle (CA), along with novel 3-directional (3d) linear measures; z-Evans Index and Brain per Ventricle Ratio (BVR). 3-Dimensional (3D) ventricular volumetry was performed as an independent correlate of ventriculomegaly to CSF responsiveness.

Results: Mean age for study participants was 71.14 ± 6.3 years (18, 85.7% males). The majority (15/21, 71.4%) of participants with NPH comprised the Complex subtype (overlay from vascular risk burden and AD); 12/21 (57.1%) were Non-Responders to ELD. Frailty alone was insufficient in distinguishing between NPH subtypes. By contrast, 3d linear measures distinguished NPH from both AD and HC cohorts, but also correlated to CSF responsiveness. The z-Evans Index was the most sensitive volumetric measure of CSF responsiveness (p = 0.012). Changes in 3d morphological indices across timepoints distinguished between Responders vs. Non-Responders to lumbar testing. There was a significant reduction of indices, only in Non-Responders and across multiple measures (z-Evans Index; p = 0.001, BVR at PC; p = 0.024). This was due to a significant decrease in ventricular measurement (p = 0.005) that correlated to independent 3D volumetry (p = 0.008).

Conclusion. In the context of multimorbidity burden, frailty risks and overlay from neurodegenerative disease, 3d morphological indices demonstrated utility in distinguishing hydrocephalus vs. non-hydrocephalus and degree of CSF responsiveness. Further work may support the characterization of patients with Complex NPH who would best benefit from the risks of interventions.

Unruptured cerebral aneurysms in elderly patients: key challenges and management

Unruptured cerebral aneurysms are increasingly identified in elderly patients as the global life expectancy continues to rise and non-invasive vascular imaging becomes more prevalent. The optimal management of unruptured aneurysms in elderly patients remains controversial. Variability in life expectancy, comorbidities and rupture risk coupled with heterogenous endovascular and surgical treatments contribute to a paucity of clear guidelines, and current management is highly individualized. Elderly patients present unique considerations including frailty, cognitive dysfunction, vasculopathy, reduced life expectancy and overall worse prognosis in case of rupture which shape the risks and likelihood of success of endovascular and microsurgical treatment. In this review, we provide a comprehensive overview of unruptured cerebral aneurysms in the elderly, with a particular focus on the natural history, key challenges associated with advanced age, management and future innovations to further refine treatment.Key MessagesThe management of unruptured cerebral aneurysms in elderly patients remains controversial.Key challenges including frailty, cognitive dysfunction, reduced life expectancy, vasculopathy and poor prognosis with aneurysm rupture add complexity to endovascular and surgical decision making not encountered with younger demographics.A thorough understanding of available treatment options, likelihood of treatment success and associated risks weighed against the risk of aneurysm rupture informs patient discussion and management.

Demographics and Outcomes of Interhospital Transfer Patients Undergoing Intracranial Tumor Resection: A Retrospective Cohort Analysis

Introduction

Interhospital transfer (IHT) contributes to increasing health care costs and typically accounts for increased patient morbidity and mortality compared to non-IHT patients. IHT inefficiencies leave patients vulnerable to delayed care and subsequent poor outcomes. In this study, we investigated factors influencing IHT of patients undergoing intracranial tumor resection (ITR), by comparing the variables distinguishing IHTs from non-IHT patients.

Methods

We performed a single-center retrospective review comparing IHT and non-IHT patients undergoing ITR from 2016 to 2018. Study variables included age, sex, race, the Milan Complexity Scale (MCS) score, 11-factor modified frailty index (mFI-11), length of stay (LOS), and Clavien-Dindo Score (CDS). Chi-square and Mann-Whitney U tests were used to identify significant differences in these variables between groups, while variables predictive of transfer status were identified using binary logistic regression.

Results

Data were collected from 219 patients undergoing ITR, with 80 (36.5%) IHT patients overall. The average age was 52 years (SD 18) and 57.7% were men. The MCS score was significantly higher in the IHT group (p = 0.014); however, mFI-11 was not (p = 0.322). The MCS score was predictive of IHT status in regression analysis (OR 1.17, p = 0.034). The IHT patients had a longer LOS (12 days vs 8 days, p = 0.014) with a lower CDS (p = 0.02).

Conclusion

The transfer patients for intracranial tumor resection had a higher MCS score and thus comprised a more surgically challenging population compared to non-transfer patients. As expected, IHT patients had a longer LOS as they lived further from hospital by definition.

Does Frailty or Age Increase the Risk of Postoperative Complications Following Cochlear Implantation?

Objective

To evaluate whether frailty or age increases the risk of postoperative complications following cochlear implant (CI) surgery.

Study Design

Retrospective cohort study.

Setting

Tertiary academic center.

Methods

An evaluation of all adult patients undergoing cochlear implantation between 2006 and 2020 was performed. The 5-item Modified Frailty Index (mFI-5, comprising preoperative history of pulmonary disease, heart failure, hypertension, diabetes, and partially/totally dependent functional status) was calculated for all patients included in analysis in addition to demographic characteristics. The primary outcome was postoperative complications following CI within a 3-month period. Major complications included myocardial infarction, bleeding, and cerebrospinal fluid leak, among others. Predictors of postoperative complications were examined using multivariable logistic regression reporting odds ratios (ORs) and 95% CIs.

Results

There were 520 patients included for review with a median age of 68 (range, 18-94) years and a slight male predominance (n = 283, 54.4%). There were 340 patients (65.4%) who were robust (nonfrail) with an mFI of 0, while 180 (34.6%) had an mFI of ≥1. There were 20 patients who experienced a postoperative complication (3.85%). There was no statistically significant association between postoperative complications as a result of preoperative frailty (OR, 1.56; 95% CI, 0.98-2.48, P = .06) or age as a continuous variable (OR, 0.99; 95% CI, 0.97-1.02, P = .51).

Conclusions

CI is safe for elderly and frail patients and carries no additional risk of complications when compared to younger, healthier patients. While medical comorbidities should always be considered perioperatively, this study supports the notion that implantation is low risk in older, frail patients.

Impact of modified Frailty Index-11 (mFI-11) on postoperative complications in patients undergoing transsphenoidal resection of pituitary tumors: Analysis of 2006-2014 ACS-NSQIP database

INTRODUCTION

Frailty is a measure of physiologic reserve that is frequently cited as a predictor of postoperative complications. However, the effect of frailty on patients undergoing a relatively common procedure such as transsphenoidal resection of pituitary tumors (TSRPT) is unknown. Therefore, we sought to explore this relationship using a large, national database.

METHODS

The 2006-2014 American College of Surgeons National Surgical Quality Improvement Program database was retrospectively reviewed to identify all patients who underwent TSRPT. Frailty scores were assigned using the established 11-factor modified Frailty Index (mFI-11). Patients were divided into low-frailty and high-frailty groups, based on mFI comorbidities of ≤ 1 and ≥ 2, respectively. Univariable and multivariable analyses were performed to evaluate the impact of frailty on postoperative outcomes and mortality.

RESULTS

A total of 993 patients were included in the analysis. The low-frailty group consisted of 825 patients; the high-frailty group comprised 168 patients. In univariable analysis, there were no significant differences in medical (low-frailty 4.8%, high-frailty 8.3%; p = 0.069) and surgical (low-frailty 1.1%, high-frailty 1.2%; p = 1.000) complications; however, the high-frailty group had a higher rate of mortality (3%) when compared with the low-frailty group (0.6%; p = 0.016, OR 4.07, p = 0.044) and longer hospitalization (4.5 ± 7.4 vs. 5.8 ± 6.8 days; p = 0.023). In multivariable analysis, frailty was a predictor of mortality but not complications or reoperation.

CONCLUSIONS

Our study shows that frailty, as measured by the mFI-11, does not predict postoperative complications in patients who undergo TSRPT, but greater frailty is correlated with higher mortality and increased hospital length of stay.

Association of preoperative frailty with postoperative delirium after elective brain tumor resection: Retrospective analysis of a prospective cohort

BACKGROUND

Preoperative frailty is associated with poor outcomes in major surgery. Postoperative delirium is common after neurosurgery. To date, the association of preoperative frailty with postoperative delirium after neurosurgery has not been established. We aimed to determine the association between preoperative frailty and postoperative delirium in patients undergoing elective brain tumor resection.

METHODS

We retrospectively analyzed the data of a prospective cohort, consecutively enrolling adult patients admitted to the intensive care unit after elective craniotomy for brain tumor resection under general anesthesia in a tertiary hospital in China from March 1, 2017 to February 2, 2018. Preoperative frailty was evaluated using the modified frailty index. The primary outcome was postoperative delirium, assessed using the Confusion Assessment Method for the Intensive Care Unit. Univariate and multivariable regression analyses were performed to examine the association.

RESULTS

659 patients met inclusion criteria for our analysis. There were 398 (60.4%) non-frail (modified frailty index = 0), 237 (36.0%) pre-frail (modified frailty index = 1-2), and 24 (3.6%) frail (modified frailty index ≥ 3) patients. Of these, 124 (18.8%) developed postoperative delirium. In adjusted analyses, frailty was independently associated with postoperative delirium (odds ratio 1.7, 95% confidence interval 1.0-2.7, P = .032). Frail patients had longer length of hospital stay and higher total costs than non-frail patients.

CONCLUSION

Preoperative frailty is associated with postoperative delirium, length of hospital stay, and total costs in patients undergoing elective brain tumor resection. Preoperative frailty assessment and appropriate management strategies should be involved in the perioperative management of postoperative delirium.

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

OBJECTIVE

Spinal epidural abscess (SEA) patients have increased medical comorbidities and risk factors for infection compared with those without SEA. However, the association between frailty and SEA patients has not been documented.

METHODS

A total of 46 SEA patients were randomly paired and matched by age and sex with a control group of patients with back pain who had presented to our emergency department from 2012 to 2017. Statistical analysis identified the risk factors associated with SEA and frailty using the modified frailty index (mFI), and the patients were stratified into robust, prefrail, and frail groups. We examined the value of the mFI as a prognostic predictor and evaluated the classic risk factors (CRFs).

RESULTS

The SEA patients had higher mFIs and CRFs (P = 0.023 and P < 0.001, respectively) and a longer length of stay (22.89 days vs. 1.72 days; P < 0.001). Of the mFI variables, only diabetes had a significant association with SEA (odds ratio [OR], 3.60; P = 0.012). Among the stratified mFI subgroups, a frail ranking (mFI >2) was the strongest risk factor for SEA (OR, 5.18; P = 0.003). A robust ranking (mFI, 0-1) was a weak negative predictor for SEA (OR, 0.41; P = 0.058). The robust patients were also more likely to be discharged to home (OR, 7.58; P = 0.002). Of the CRF variables, only intravenous drug use had a statistically significant association with SEA (OR, 10.72; P = 0.015).

CONCLUSIONS

Patients with SEA were more frail compared with the control back pain patients. Frailty was determined to be an independent risk factor for SEA, outside of the CRFs. The use of the mFI could be potentially useful in predicting the diagnosis, prognosticating, and guiding SEA treatment.

Performance assessment of the metastatic spinal tumor frailty index using machine learning algorithms: limitations and future directions

OBJECTIVE

Frailty is recognized as an important consideration in patients with cancer who are undergoing therapies, including spine surgery. The definition of frailty in the context of spinal metastases is unclear, and few have studied such markers and their association with postoperative outcomes and survival. Using national databases, the metastatic spinal tumor frailty index (MSTFI) was developed as a tool to predict outcomes in this specific patient population and has not been tested with external data. The purpose of this study was to test the performance of the MSTFI with institutional data and determine whether machine learning methods could better identify measures of frailty as predictors of outcomes.

METHODS

Electronic health record data from 479 adult patients admitted to the Massachusetts General Hospital for metastatic spinal tumor surgery from 2010 to 2019 formed a validation cohort for the MSTFI to predict major complications, in-hospital mortality, and length of stay (LOS). The 9 parameters of the MSTFI were modeled in 3 machine learning algorithms (lasso regularization logistic regression, random forest, and gradient-boosted decision tree) to assess clinical outcome prediction and determine variable importance. Prediction performance of the models was measured by computing areas under the receiver operating characteristic curve (AUROCs), calibration, and confusion matrix metrics (positive predictive value, sensitivity, and specificity) and was subjected to internal bootstrap validation.

RESULTS

Of 479 patients (median age 64 years [IQR 55-71 years]; 58.7% male), 28.4% had complications after spine surgery. The in-hospital mortality rate was 1.9%, and the mean LOS was 7.8 days. The MSTFI demonstrated poor discrimination for predicting complications (AUROC 0.56, 95% CI 0.50-0.62) and in-hospital mortality (AUROC 0.69, 95% CI 0.54-0.85) in the validation cohort. For postoperative complications, machine learning approaches showed a greater advantage over the logistic regression model used to develop the MSTFI (AUROC 0.62, 95% CI 0.56-0.68 for random forest vs AUROC 0.56, 95% CI 0.50-0.62 for logistic regression). The random forest model had the highest positive predictive value (0.53, 95% CI 0.43-0.64) and the highest negative predictive value (0.77, 95% CI 0.72-0.81), with chronic lung disease, coagulopathy, anemia, and malnutrition identified as the most important predictors of postoperative complications.

CONCLUSIONS

This study highlights the challenges of defining and quantifying frailty in the metastatic spine tumor population. Further study is required to improve the determination of surgical frailty in this specific cohort.