90-day Readmission After Lumbar Spinal Fusion Surgery in New York State Between 2005 and 2014: A 10-year Analysis of a Statewide Cohort

Risk Factors of 90-Day Unplanned Readmission After Lumbar Spine Surgery for Degenerative Lumbar Disk Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

With the increasing aging population, the number of patients undergoing lumbar spinal surgery for degenerative changes is rising. In the United States, spinal fusion surgery ranked sixth in operating room procedures, accounting for 3.2% of all such procedures, with an aggregate cost for stays amounting to $14.1 billion, making it the most expensive operating room procedure in 2018. The aim of this study was to identify valid risk factors of 90-day unplanned readmissions after lumbar spine surgery through a meta-analysis, with the goal of saving insurance finances and improving patient clinical outcomes.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library databases using the search terms "90-day readmission" and "lumbar spine surgery." Eleven eligible studies were included. Characteristic differences between readmitted and nonreadmitted patients were identified and analyzed using Review Manager software.

RESULTS

This meta-analysis included 11 studies with a total of 648 415 patients; 50 047 were readmitted unplanned after lumbar spine surgery. The incidence of unplanned readmission after lumbar spine surgery was 7.72%. Among demographic risk factors, older age and higher body mass index were significantly associated with unplanned readmission after lumbar spine surgery. Patient characteristics, such as depression, diabetes mellitus, hypertension, renal failure, and an American Society of Anesthesiologists grade greater than 2 were also significantly associated with unplanned readmission after lumbar spine surgery.

CONCLUSION

The meta-analysis revealed a 7.72% incidence of unplanned readmission after lumbar spine surgery. These findings suggest the need for enhanced preoperative optimization and careful patient selection for lumbar spine surgery, particularly in elderly patients and those with multiple comorbidities. Implementation of targeted preventive strategies for high-risk patients may help reduce unplanned readmissions and improve healthcare resource utilization.

Predictive Value of Preoperative Nutritional Risk Index for Screw Loosening After Lumbar Interbody Fusion in Elderly Patients With Lumbar Spine Diseases

OBJECTIVE

Pedicle screw loosening is one of the common complications in elderly patients undergoing transforaminal lumbar interbody fusion (TLIF) for lumbar spine disease. Malnutrition, prevalent among elderly patients, has been shown to be associated with increased complications. The Geriatric Nutritional Risk Index (GNRI) serves as a simple indicator of nutritional status. However, the relationship between malnutrition, particularly GNRI, and pedicle screw loosening has not been adequately investigated. This study aims to investigate the relationship between GNRI and pedicle screw loosening following TLIF to guide the perioperative nutritional management of patients and prevent postoperative complications.

METHODS

A retrospective review was conducted on clinical data from patients who underwent single-level TLIF between 2014 and 2022. Data collection encompassed patient demographics, preoperative laboratory parameters, surgery-related data, perioperative radiographic data, and patient-reported outcomes were comprehensively documented. All patients were followed up for a minimum of 12 months. The relationship between GNRI and pedicle screw loosening was evaluated by univariate and multivariate Cox regression analysis, restricted cubic spline (RCS) analysis, receiver operating characteristic (ROC) analysis, and Kaplan-Meier survival analysis.

RESULTS

A total of 426 patients were included in the study. The rate of pedicle screw loosening rate was 16.4% at a minimum follow-up of 12 months. Patients with pedicle screw loosening exhibited significantly lower GNRI (89.0 ± 8.0 vs. 99.2 ± 9.3, p < 0.001) and volumetric bone mineral density measured by quantitative computed tomography (QCT-vBMD) (84.2 [interquartile range (IQR) 79.6-92.2] vs. 104.0 [IQR 88.2-126.0] mg/cm3, p < 0.001) compared with those in the non-loosening group. Multivariate Cox regression analysis identified sex (hazard ratio [HR] 1.433, 95% confidence interval [CI] 0.714-2.876, p = 0.027), age (HR 1.062, 95% CI 1.014-1.113, p = 0.012), GNRI (HR 0.841, 95% CI 0.711-0.994, p = 0.043), and QCT-vBMD (HR 0.982, 95% CI 0.967-0.997, p = 0.019) as independent risk factors for screw loosening. RCS analysis showed that GNRI was negatively correlated with screw loosening (p < 0.0001). The area under the curve (AUC) for the GNRI in predicting pedicle screw loosening was 0.794, with a cut-off value of 95.590 (sensitivity, 85.7%; specificity 65.2%). Kaplan-Meier survival analysis identified that the lower-level GNRI group exhibited a higher cumulative incidence of screw loosening (log-rank test, p < 0.0001).

CONCLUSION

The GNRI was an independent risk factor for postoperative screw loosening in elderly patients undergoing TLIF for lumbar spine disease. Preoperative GNRI may potentially serve as a valuable tool in predicting postoperative screw loosening in elderly patients undergoing TLIF.

Addressing the Impact of Race and Ethnicity on Musculoskeletal Spine Care in the United States

➤ Despite being a social construct, race has an impact on outcomes in musculoskeletal spine care.➤ Race is associated with other social determinants of health that may predispose patients to worse outcomes.➤ The musculoskeletal spine literature is limited in its understanding of the causes of race-related outcome trends.➤ Efforts to mitigate race-related disparities in spine care require individual, institutional, and national initiatives.

Pre-operative bone quality deficits and risk of complications following spine fusion surgery among postmenopausal women

Poor bone quality is a risk factor for complications after spinal fusion surgery. This study investigated pre-operative bone quality in postmenopausal women undergoing spine fusion and found that those with small bones, thinner cortices and surgeries involving more vertebral levels were at highest risk for complications.

PURPOSE

Spinal fusion is one of the most common surgeries performed worldwide. While skeletal complications are common, underlying skeletal deficits are often missed by pre-operative DXA due to artifact from spinal pathology. This prospective cohort study investigated pre-operative bone quality using high resolution peripheral CT (HRpQCT) and its relation to post-operative outcomes in postmenopausal women, a population that may be at particular risk for skeletal complications. We hypothesized that women with low volumetric BMD (vBMD) and abnormal microarchitecture would have higher rates of post-operative complications.

METHODS

Pre-operative imaging included areal BMD (aBMD) by DXA, cortical and trabecular vBMD and microarchitecture of the radius and tibia by high resolution peripheral CT. Intra-operative bone quality was subjectively graded based on resistance to pedicle screw insertion. Post-operative complications were assessed by radiographs and CTs.

RESULTS

Among 50 women enrolled (age 65 years), mean spine aBMD was normal and 35% had osteoporosis by DXA at any site. Low aBMD and vBMD were associated with "poor" subjective intra-operative quality. Skeletal complications occurred in 46% over a median follow-up of 15 months. In Cox proportional models, complications were associated with greater number of surgical levels (HR 1.19 95% CI 1.06-1.34), smaller tibia total area (HR 1.67 95% CI1.16-2.44) and lower tibial cortical thickness (HR 1.35 95% CI 1.05-1.75; model p < 0.01).

CONCLUSION

Women with smaller bones, thinner cortices and procedures involving a greater number of vertebrae were at highest risk for post-operative complications, providing insights into surgical and skeletal risk factors for complications in this population.

30-and 90-day readmissions in lumbar spine surgery. Differences in prevalence and causes

BACKGROUND

The morbidity associated with surgical treatment of lumbar degenerative conditions has attracted increasing interest due to the economic impact on society, especially postoperative readmission. Limited studies have assessed this risk in a prospective, single-center consecutive fashion.

OBJECTIVE

To assess the incidence and causes of 30- and 90-day unplanned readmission and revision surgery following surgical treatment for lumbar degenerative spine conditions at a tertiary treatment center.

STUDY DESIGN

Prospective, single-center cohort study.

METHODS

All patients undergoing degenerative lumbar spine surgery in a 1-year period from February 1st, 2016, were prospectively included. Patient characteristics, surgical information and information regarding postoperative complications, including readmission (30- and 90-days) and revision surgery were recorded. Readmissions were classified according to whether they were due to the surgical intervention specifically, or a medical complication.

RESULTS

A total of 1399 patients underwent surgery for various lumbar degenerative pathologies in the study period and all were included. Of these, 9.4% (n = 132) were readmitted within 30 days of surgery and in some cases, multiple readmissions occurred (up to 3). The total 90-day readmission rate was 17.6%. Of these, 15% were related to the surgical procedure. The predominant medical related causes were systemic infection (30-day: 14.4%, 90-day: 10.7%), neurological symptoms (30-day: 6.3%, 90-day: 5.0%) and cardiovascular events (30-day: 8.1%, 90-day: 12.9%). The surgical related causes for readmission were pain (30-day: 13.1%, 90-day: 2.9%), wound complications (30-day: 11.3%, 90-day: 5.0% and re-herniation (30-day: 13.1%, 90-day: 2.9%). Age was the only factor with significant influence on readmission.

CONCLUSION

The incidence of medical conditions causing unplanned 30-day readmissions following surgery for lumbar degenerative conditions, is significantly higher compared to readmissions related specifically to the surgical procedure. Examples of medical treatment included antibiotics, analgesics, laxatives, anticoagulants and beta blockers. The difference is even more pronounced for the 90-day readmissions. The predominant medical causes were systemic infections, neurological and cardiovascular events. Predominant causes related to the surgery were pain, wound complications and re-herniations. Readmissions may be reduced by optimizing the medical treatment and the pain management before discharge of the patient.

Complications of the Prone Transpsoas Lateral Lumbar Interbody Fusion for Degenerative Lumbar Spine Disease: A Multicenter Study

BACKGROUND AND OBJECTIVES

The prone transpsoas (PTP) approach for lateral lumbar interbody fusion (LLIF) is a novel technique for degenerative lumbar spine disease. However, there is a paucity of information in the literature on the complications of this procedure, with all published data consisting of small samples. We aimed to report the intraoperative and postoperative complications of PTP in the largest study to date.

METHODS

A retrospective electronic medical record review was conducted at 11 centers to identify consecutive patients who underwent LLIF through the PTP approach between January 1, 2021, and December 31, 2021. The following data were collected: intraoperative characteristics (operative time, estimated blood loss [EBL], intraoperative complications [anterior longitudinal ligament (ALL) rupture, cage subsidence, vascular and visceral injuries]), postoperative complications, and hospital stay.

RESULTS

A total of 365 patients were included in the study. Among these patients, 2.2% had ALL rupture, 0.3% had cage subsidence, 0.3% had a vascular injury, 0.3% had a ureteric injury, and no other visceral injuries were reported. Mean operative time was 226.2 ± 147.9 minutes. Mean EBL was 138.4 ± 215.6 mL. Mean hospital stay was 2.7 ± 2.2 days. Postoperative complications included new sensory symptoms-8.2%, new lower extremity weakness-5.8%, wound infection-1.4%, cage subsidence-0.8%, psoas hematoma-0.5%, small bowel obstruction and ischemia-0.3%, and 90-day readmission-1.9%.

CONCLUSION

In this multicenter case series, the PTP approach was well tolerated and associated with a satisfactory safety profile.

Readmission and Resource Utilization in Patients From Socioeconomically Distressed Communities Following Lumbar Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine whether: (1) patients from communities of socioeconomic distress have higher readmission rates or postoperative healthcare resource utilization and (2) there are differences in patient-reported outcome measures (PROMs) based on socioeconomic distress.

SUMMARY OF BACKGROUND DATA

Socioeconomic disparities affect health outcomes, but little evidence exists demonstrating the impact of socioeconomic distress on postoperative resource utilization or PROMs.

METHODS

A retrospective review was performed on patients who underwent lumbar fusion at a single tertiary academic center from January 1, 2011 to June 30, 2021. Patients were classified according to the distressed communities index. Hospital readmission, postoperative prescriptions, patient telephone calls, follow-up office visits, and PROMs were recorded. Multivariate analysis with logistic, negative binomial regression or Poisson regression were used to investigate the effects of distressed communities index on postoperative resource utilization. Alpha was set at P <0.05.

RESULTS

A total of 4472 patients were included for analysis. Readmission risk was higher in distressed communities (odds ratio, 1.75; 95% confidence interval, 1.06-2.87; P =0.028). Patients from distressed communities (odds ratio, 3.94; 95% confidence interval, 1.60-9.72; P =0.003) were also more likely to be readmitted for medical, but not surgical causes ( P =0.514), and distressed patients had worse preoperative (visual analog-scale Back, P <0.001) and postoperative (Oswestry disability index, P =0.048; visual analog-scale Leg, P =0.013) PROMs, while maintaining similar magnitudes of clinical improvement. Patients from distressed communities were more likely to be discharged to a nursing facility and inpatient rehabilitation unit (25.5%, P =0.032). The race was not independently associated with readmissions ( P =0.228).

CONCLUSION

Socioeconomic distress is associated with increased postoperative health resource utilization. Patients from distressed communities have worse preoperative PROMs, but the overall magnitude of improvement is similar across all classes.

LEVEL OF EVIDENCE

Level IV.

Disparities in Elective Spine Surgery for Medicaid Beneficiaries: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

We sought to synthesize the literature investigating the disparities that Medicaid patients sustain with regards to 2 types of elective spine surgery, lumbar fusion (LF) and anterior cervical discectomy and fusion (ACDF).

METHODS

Our review was constructed in accordance with Preferred Reporting Items and Meta-analyses (PRISMA) guidelines and protocol. We systematically searched PubMed, Embase, Scopus, CINAHL, and Web of Science databases. We included studies comparing Medicaid beneficiaries to other payer categories with regards to rates of LF and ACDF, costs/reimbursement, and health outcomes.

RESULTS

A total of 573 articles were assessed. Twenty-five articles were included in the analysis. We found that the literature is consistent with regards to Medicaid disparities. Medicaid was strongly associated with decreased access to LF and ACDF, lower reimbursement rates, and worse health outcomes (such as higher rates of readmission and emergency department utilization) compared to other insurance categories.

CONCLUSIONS

In adult patients undergoing elective spine surgery, Medicaid insurance is associated with wide disparities with regards to access to care and health outcomes. Efforts should focus on identifying causes and interventions for such disparities in this vulnerable population.

Early Readmission and Reoperation After Percutaneous Transforaminal Endoscopic Decompression for Degenerative Lumbar Spinal Stenosis: Incidence and Risk Factors

PURPOSE

To identify the incidence rates and risk factors for early readmission and reoperation after percutaneous transforaminal endoscopic decompression (PTED) for degenerative lumbar spinal stenosis (DLSS).

PATIENTS AND METHODS

A total of 1011 DLSS patients who underwent PTED were retrospectively evaluated. Of them, 58 were readmitted, and 31 underwent reoperation. The patients were matched with 174 control patients to perform case-control analyses. The clinical and preoperative imaging data of each patient were recorded. Univariate analyses were performed using independent sample t-tests and Fisher's exact tests. Furthermore, the risk factors for early readmission and reoperation were analyzed using multivariate logistic regression analyses.

RESULTS

The incidence rates of readmission and reoperation within 90 days after PTED were 5.7% and 3.1%, respectively. Age (odds ratio [OR]=1.054, p=0.001), BMI (OR=1.104, p=0.041), a history of lumbar surgery (OR=3.260, p=0.014), and the number of levels with radiological lumbar foraminal stenosis (LFS, OR=2.533, p<0.001) were independent risk factors for early readmission. The number of levels with radiological LFS (OR=5.049, p<0.001), the grade of surgical-level facet joint degeneration (OR=2.010, p=0.023), and a history of lumbar surgery (OR=10.091, p<0.001) were independent risk factors for early reoperation.

CONCLUSION

This study confirmed that aging, a higher BMI, a history of lumbar surgery, and more levels with radiological LFS were associated with a higher risk of early readmission. More levels with radiological LFS, a higher grade of surgical-level facet joint degeneration, and a history of lumbar surgery were predictors of early reoperation. These results are helpful in patient counseling and perioperative evaluation of PTED.

Characteristics of Patients Selected for Surgical Treatment of Spinal Meningioma

BACKGROUND

Spinal meningiomas are benign extra-axial tumors that can present with neurological deficits. Treatment partly depends on the degree of disability as there is no agreed-upon patient selection algorithm at present. We aimed to elucidate general patient selection patterns in patients undergoing surgery for spinal meningioma.

METHODS

Data for patients with spinal tumors admitted between 2016 and 2019 were extracted from the U.S. Nationwide Inpatient Sample. We identified patients with a primary diagnosis of spinal meningioma (using International Classification of Disease, 10^th revision codes) and divided them into surgical and nonsurgical treatment groups. Patient characteristics were evaluated for intergroup differences.

RESULTS

Of 6395 patients with spinal meningioma, 5845 (91.4%) underwent surgery. Advanced age, nonwhite race, obesity, diabetes mellitus, chronic renal failure, and anticoagulant/antiplatelet use were less prevalent in the surgical group (all P < 0.001). The only positive predictor of surgical treatment was elective admission status (odds ratio, 3.166; P < 0.001); negative predictors were low income, Medicaid insurance, anxiety, obesity, and plegia. Patients with bowel-bladder dysfunction, plegia, or radiculopathy were less likely to undergo surgical treatment. The surgery group was less likely to experience certain complications (deep vein thrombosis, P < 0.001; pulmonary embolism, P = 0.002). Increased total hospital charges were associated with nonwhite race, diabetes, depression, obesity, myelopathy, plegia, and surgery.

CONCLUSIONS

Patients treated surgically had a decreased incidence of complications, comorbidities, and Medicaid payer status. A pattern of increased utilization of health care resources and spending was also observed in the surgery group. The results indicate a potentially underserved population of patients with spinal meningioma.

The Impact of Isolated Baseline Cannabis Use on Outcomes Following Thoracolumbar Spinal Fusion: A Propensity Score-Matched Analysis

BACKGROUND

There is limited literature evaluating the impact of isolated cannabis use on outcomes for patients following spinal surgery. This study sought to compare 90-day complication, 90-day readmission, as well as 2-year revision rates between baseline cannabis users and non-users following thoracolumbar spinal fusion (TLF) for adult spinal deformity (ASD).

METHODS

The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried between January 2009 and September 2013 to identify all patients who underwent TLF for ASD. Inclusion criteria were age ≥18 years and either minimum 90-day (for complications and readmissions) or 2-year (for revisions) follow-up surveillance. Cohorts were created and propensity score-matched based on presence or absence of isolated baseline cannabis use. Baseline demographics, hospital-related parameters, 90-day complications and readmissions, and two-year revisions were retrieved. Multivariate binary stepwise logistic regression identified independent outcome predictors.

RESULTS

704 patients were identified (n=352 each), with comparable age, sex, race, primary insurance, Charlson/Deyo scores, surgical approach, and levels fused between cohorts (all, p>0.05). Cannabis users (versus non-users) incurred lower 90-day overall and medical complication rates (2.4% vs. 4.8%, p=0.013; 2.0% vs. 4.1%, p=0.018). Cohorts had otherwise comparable complication, revision, and readmission rates (p>0.05). Baseline cannabis use was associated with a lower risk of 90-day medical complications (OR=0.47, p=0.005). Isolated baseline cannabis use was not associated with 90-day surgical complications and readmissions, or two-year revisions.

CONCLUSION

Isolated baseline cannabis use, in the absence of any other diagnosed substance abuse disorders, was not associated with increased odds of 90-day surgical complications or readmissions or two-year revisions, though its use was associated with reduced odds of 90-day medical complications when compared to non-users undergoing TLF for ASD. Further investigations are warranted to identify the physiologic mechanisms underlying these findings. Level of Evidence: III.

Natural language processing for prediction of readmission in posterior lumbar fusion patients: which free-text notes have the most utility?

BACKGROUND CONTEXT

The increasing volume of free-text notes available in electronic health records has created an opportunity for natural language processing (NLP) algorithms to mine this unstructured data in order to detect and predict adverse outcomes. Given the volume and diversity of documentation available in spine surgery, it remains unclear which types of documentation offer the greatest value for prediction of adverse outcomes.

STUDY DESIGN/SETTING

Retrospective review of medical records at two academic and three community hospitals.

PURPOSE

The purpose of this study was to conduct an exploratory analysis in order to examine the utility of free-text notes generated during the index hospitalization for lumbar spine fusion for prediction of 90-day unplanned readmission.

PATIENT SAMPLE

Adult patients 18 years or older undergoing lumbar spine fusion for lumbar spondylolisthesis or lumbar spinal stenosis between January 1, 2016 and December 31, 2020.

OUTCOME MEASURES

The primary outcome was inpatient admission within 90-days of discharge from the index hospitalization.

METHODS

The predictive performance of NLP algorithms developed by using discharge summary notes, operative notes, nursing notes, physical therapy notes, case management notes, medical doctor (MD) (resident or attending), and allied practice professional (APP) (nurse practitioner or physician assistant) notes were assessed by discrimination, calibration, overall performance.

RESULTS

Overall, 708 patients were included in the study and 83 (11.7%) had 90-day inpatient readmission. In the independent testing set of patients (n=141) not used for model development, the area under the receiver operating curve of NLP algorithms for prediction of 90-day readmission using discharge summary notes, operative notes, nursing notes, physical therapy notes, case management notes, MD/APP notes was 0.70, 0.57, 0.57, 0.60, 0.60, and 0.49 respectively.

CONCLUSION

In this exploratory analysis, discharge summary, physical therapy, and case management notes had the most utility and daily MD/APP progress notes had the least utility for prediction of 90-day inpatient readmission in lumbar fusion patients among the free-text documentation generated during the index hospitalization.

Readmissions after elective orthopedic surgery in a comprehensive co-management care system-a retrospective analysis

Background

No surgical intervention is without risk. Readmissions and reoperations after elective orthopedic surgery are common and are also stressful for the patient. It has been shown that a comprehensive ortho-medical co-management model decreases readmission rates in older patients suffering from hip fracture; but it is still unclear if this also applies to elective orthopedic surgery. The aim of the current study was to determine the proportion of unplanned readmissions or returns to operating room (for any reason) across a broad elective orthopedic population within 90 days after elective surgery. All cases took place in a tertiary care center using co-management care and were also assessed for risk factors leading to readmission or unplanned return to operating room (UROR).

Methods

In this observational study, 1295 patients undergoing elective orthopedic surgery between 2015 and 2017 at a tertiary care center in Switzerland were investigated. The proportion of reoperations and readmissions within 90 days was measured, and possible risk factors for reoperation or readmission were identified using logistic regression.

Results

In our cohort, 3.2% (42 of 1295 patients) had an UROR or readmission. Sixteen patients were readmitted without requiring further surgery—nine of which due to medical and seven to surgical reasons. Patient-related factors associated with UROR and readmission were older age (67 vs. 60 years; p = 0.014), and American Society of Anesthesiologists physical status (ASA PS) score ≥ 3 (43% vs. 18%; p < 0.001). Surgery-related factors were: implantation of foreign material (62% vs. 33%; p < 0.001), duration of operation (76 min. vs. 60 min; p < 0.001), and spine surgery (57% vs. 17%; p < 0.001). Notably, only spine surgery was also found to be independent risk factor.

Conclusion

Rates of UROR during initial hospitalization and readmission were lower in the current study than described in the literature. However, several comorbidities and surgery-related risk factors were found to be associated with these events. Although no surgery is without risk, known threats should be reduced and every effort undertaken to minimize complications in high-risk populations. Further prospective controlled research is needed to investigate the potential benefits of a co-management model in elective orthopedic surgery.

Impact of race on nonroutine discharge, length of stay, and postoperative complications after surgery for spinal metastases

OBJECTIVE

Previous studies have suggested the possibility of racial disparities in surgical outcomes for patients undergoing spine surgery, although this has not been thoroughly investigated in those with spinal metastases. Given the increasing prevalence of spinal metastases requiring intervention, knowledge about potential discrepancies in outcomes would benefit overall patient care. The objective in the present study was to investigate whether race was an independent predictor of postoperative complications, nonroutine discharge, and prolonged length of stay (LOS) after surgery for spinal metastasis.

METHODS

The authors retrospectively examined patients at a single comprehensive cancer center who had undergone surgery for spinal metastasis between April 2013 and April 2020. Demographic information, primary pathology, preoperative clinical characteristics, and operative outcomes were collected. Factors achieving p values < 0.15 on univariate regression were entered into a stepwise multivariable logistic regression to generate predictive models. Nonroutine discharge was defined as a nonhome discharge destination and prolonged LOS was defined as LOS greater than the 75th percentile for the entire cohort.

RESULTS

Three hundred twenty-eight patients who had undergone 348 operations were included: 240 (69.0%) White and 108 (31.0%) Black. On univariable analysis, cohorts significantly differed in age (p = 0.02), marital status (p < 0.001), insurance status (p = 0.03), income quartile (p = 0.02), primary tumor type (p = 0.04), and preoperative Karnofsky Performance Scale (KPS) score (p < 0.001). On multivariable analysis, race was an independent predictor for nonroutine discharge: Black patients had significantly higher odds of nonroutine discharge than White patients (adjusted odds ratio [AOR] 2.24, 95% confidence interval [CI] 1.28-3.92, p = 0.005). Older age (AOR 1.06 per year, 95% CI 1.03-1.09, p < 0.001), preoperative KPS score ≤ 70 (AOR 3.30, 95% CI 1.93-5.65, p < 0.001), preoperative Frankel grade A-C (AOR 3.48, 95% CI 1.17-10.3, p = 0.02), insurance status (p = 0.005), being unmarried (AOR 0.58, 95% CI 0.35-0.97, p = 0.04), number of levels (AOR 1.17 per level, 95% CI 1.05-1.31, p = 0.004), and thoracic involvement (AOR 1.71, 95% CI 1.02-2.88, p = 0.04) were also predictive of nonroutine discharge. However, race was not independently predictive of postoperative complications or prolonged LOS. Higher Charlson Comorbidity Index (AOR 1.22 per point, 95% CI 1.04-1.43, p = 0.01), low preoperative KPS score (AOR 1.84, 95% CI 1.16-2.92, p = 0.01), and number of levels (AOR 1.15 per level, 95% CI 1.05-1.27, p = 0.004) were predictive of complications, while insurance status (p = 0.05), income quartile (p = 0.01), low preoperative KPS score (AOR 1.64, 95% CI 1.03-2.72, p = 0.05), and number of levels (AOR 1.16 per level, 95% CI 1.05-1.30, p = 0.004) were predictive of prolonged LOS.

CONCLUSIONS

Race, insurance status, age, baseline functional status, and marital status were all independently associated with nonroutine discharge. This suggests that a combination of socioeconomic factors and functional status, rather than medical comorbidities, may best predict postdischarge disposition in patients treated for spinal metastases. Further investigation in a prospective cohort is merited.

Racial Disparities in Outcomes After Spine Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

Racial disparities are a major issue in health care but the overall extent of the issue in spinal surgery outcomes is unclear. We conducted a systematic review/meta-analysis of disparities in outcomes among patients belonging to different racial groups who had undergone surgery for degenerative spine disease.

METHODS

We searched Ovid MEDLINE, Scopus, Cochrane Review Database, and ClinicalTrials.gov from inception to January 20, 2021 for relevant articles assessing outcomes after spine surgery stratified by race. We included studies that compared outcomes after spine surgery for degenerative disease among different racial groups.

RESULTS

We found 30 studies that met our inclusion criteria (28 articles and 2 published abstracts). We included data from 20 cohort studies in our meta-analysis (3,501,830 patients), which were assessed to have a high risk of observation/selection bias. Black patients had a 55% higher risk of dying after spine surgery compared with white patients (relative risk [RR], 1.55, 95% confidence interval [CI], 1.28-1.87; I² = 70%). Similarly, black patients had a longer length of stay (mean difference, 0.93 days; 95% CI, 0.75-1.10; I² = 73%), and higher risk of nonhome discharge (RR, 1.63; 95% CI, 1.47-1.81; I² = 89%), and 30-day readmission (RR, 1.45; 95% CI, 1.03-2.04; I² = 96%). No significant difference was noted in the pooled analyses for complication or reoperation rates.

CONCLUSIONS

Black patients have a significantly higher risk of unfavorable outcomes after spine surgery compared with white patients. Further work in understanding the reasons for these disparities will help develop strategies to narrow the gap among the racial groups.

Risk Factors Associated with 90-day Readmissions Following Odontoid Fractures: A Nationwide Readmissions Database Study

STUDY DESIGN

Nationwide Readmissions Database Study.

OBJECTIVE

The aim of this study was to investigate readmission rates and factors related to readmission after surgical and nonsurgical management of odontoid fractures.

SUMMARY OF BACKGROUND DATA

Management of odontoid fractures, which are the most common isolated spine fracture in the elderly, continues to be debated. The choice between surgical or nonsurgical treatment has been reported to impact mortality and might influence readmission rates. Hospital readmissions represent a large financial burden upon our healthcare system. Factors surrounding hospital readmissions would benefit from a better understanding of their associated causes to lower health care costs.

METHODS

A retrospective study was performed using the 2016 Healthcare Utilization Project (HCUP) Nationwide Readmission Database (NRD). Demographic information and factors associated with readmission were collected. Readmission rates, complications, length of hospital stay were collected. Patients treated operatively, nonoperatively, and patients who were readmitted or not readmitted were compared. Statistical analysis was performed using open source software SciPy (Python v1.3.0) for all analyses.

RESULTS

We identified 2921 patients who presented with Type II dens fractures from January 1, 2016 to September 30, 2016, 555 of which underwent surgical intervention. The readmission rate in patients who underwent surgery was 16.4% (91/555) and 29.4% (696/2366) in the nonoperative group. Hospital costs for readmitted and nonreadmitted patients were $353,704 and $174,922, and $197,099 and $80,715 for nonoperatively managed patients, respectively. Medicaid and Medicare patients had the highest readmission rate in both groups. Charlson and Elixhauser comorbidity indices were significantly higher in patients who were readmitted (P < 0.0001).

CONCLUSION

We report an overall 90-day readmission rate of 16.4% and 29.4%, in operative and nonoperative management of type II odontoid fractures, respectively. In the face of a rising incidence of this fracture in the elderly population, an understanding of the comorbidities and age-related demographics associated with 90-day readmissions following both surgical and nonsurgical treatment are critical.Level of Evidence: 3.

Risk Factors for 30- and 90-Day Readmissions Due To Surgical Site Infection Following Posterior Lumbar Fusion

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

Identify the independent risk factors for 30- and 90-day readmission because of surgical site infection (SSI) in patients undergoing elective posterior lumbar fusion (PLF).

SUMMARY OF BACKGROUND DATA

SSI is a significant cause of morbidity in the 30- and 90-day windows after hospital discharge. There remains a gap in the literature on independent risk factors for readmission because of SSI after PLF procedures. In addition, readmission for SSI after spine surgery beyond the 30-day postoperative period has not been well studied.

METHODS

A retrospective analysis was performed on data from the 2012 to 2014 Healthcare Cost and Utilization Project Nationwide Readmissions Database. The authors identified 65,121 patients who underwent PLF. There were 191 patients (0.30%) readmitted with a diagnosis of SSI in the 30-day readmission window, and 283 (0.43%) patients readmitted with a diagnosis of SSI in the 90-day window. Baseline patient demographics and medical comorbidities were assessed. Bivariate and multivariate analyses were performed to examine the independent risk factors for readmission because of SSI.

RESULTS

In the 30-day window after discharge, this study identified patients with liver disease, uncomplicated diabetes, deficiency anemia, depression, psychosis, renal failure, obesity, and Medicaid or Medicare insurance as higher risk patients for unplanned readmission with a diagnosis of SSI. The study identified the same risk factors in the 90-day window with the addition of diabetes with chronic complications, chronic pulmonary disease, and pulmonary circulation disease.

CONCLUSIONS

Independent risk factors for readmission because of SSI included liver disease, uncomplicated diabetes, obesity, and Medicaid insurance status. These findings suggest that additional intervention in the perioperative workup for patients with these risk factors may be necessary to lower unplanned readmission because of SSI after PLF surgery.

The Impact of Obesity on Risk Factors for Adverse Outcomes in Patients Undergoing Elective Posterior Lumbar Spine Fusion

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

The aim of this study was to determine the influence of obesity on risk factors for adverse outcome after lumbar spine fusion (LSF).

SUMMARY OF BACKGROUND DATA

Obesity is risk factor for complications after LSF and poses unique challenges regarding optimization of care. Nonetheless, this patient population is not well-studied.

METHODS

Adult patients undergoing LSF were identified the State Inpatient Database. Patients were identified as obese or nonobese using ICD-9 codes. Outcome variables were 90-day readmission, major medical complication, infection, and revision rates. Data were queried for demographics, comorbidities, surgery characteristics, and outcome variables. Logistic multivariate regression was utilized, serially testing interactions between obesity and other independent variables in separate models for each outcome. The Benjamini-Hochberg procedure was used to adjust statistical significance for multiple comparisons.

RESULTS

A total of 262,153 patients were included: 31,062 obese and 231, 091 nonobese. For major complications, obese patients had lower odds ratios (ORs) versus nonobese patients for cerebrovascular accident, diabetes with chronic complications, age ≥65, congestive heart failure, history of myocardial infarction, renal disease, chronic pulmonary disease, Medicare/Medicaid payor, more than two levels fused, transforaminal/posterior lumbar interbody fusion, and female sex, and higher OR for non-White race. For readmission, obese patients had lower OR for age ≥65, history of MI, renal disease, and mental health disease, and higher OR for female sex. For revision, obese patients had higher OR for female sex and TLIF/PLIF. For infection, obese patients had lower OR for diabetes with and without chronic complications, and higher OR for female sex.

CONCLUSION

Many medical comorbidities have less impact in obese patients than nonobese patients in predicting adverse outcomes despite increased rates of adverse outcomes in obese patients. These findings reflect the impact of obesity as an independent risk factor and have important implications for preoperative optimization.Level of Evidence: 3.

Comparative Demographics and Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion in Chinese, Malays, and Indians

STUDY DESIGN

This study carried out a retrospective review of prospectively collected registry data.

OBJECTIVE

This study aimed to determine whether (1) utilization rates; (2) demographics and preoperative statuses; and (3) clinical outcomes differ among Chinese, Malays, and Indians undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

SUMMARY OF BACKGROUND DATA

There is a marked racial disparity in spine surgery outcomes between white and African American patients. Comparative studies of ethnicity have mostly been carried out in American populations, with an underrepresentation of Asian ethnic groups. It is unclear whether these disparities exist among Chinese, Malays, and Indians.

METHODS

A prospectively maintained registry was reviewed for 753 patients who underwent primary MIS-TLIF for degenerative spondylolisthesis between 2006 and 2013. The cohort was stratified by race. Comparisons of demographics, functional outcomes, and patient satisfaction were performed preoperatively and 1 month, 3 months, 6 months, and 2 years postoperatively.

RESULTS

Compared with population statistics, there was an overrepresentation of Chinese (6.6%) and an underrepresentation of Malays (5.0%) and Indians (3.5%) who underwent MIS-TLIF. Malays and Indians were younger and had higher body mass index at the time of surgery compared with Chinese. After adjusting for age, sex, and body mass index, Malays had significantly worse back pain and Indians had poorer Short-Form 36 Physical Component Summary compared with Chinese preoperatively. Chinese also had a better preoperative Oswestry Disability Index compared with the other races. Although significant differences remained at 1 month, there was no difference in outcomes up to 2 years postoperatively, except for a lower Physical Component Summary in Indians compared with Chinese at 2 years. The rate of minimal clinically important difference attainment, satisfaction, and expectation fulfillment was also comparable. At 2 years, 87.0% of Chinese, 76.9% of Malays, and 91.7% of Indians were satisfied.

CONCLUSION

The variations in demographics, preoperative statuses, and postoperative outcomes between races should be considered when interpreting outcome studies of lumbar spine surgery in Asian populations.

LEVEL OF EVIDENCE

Level III-nonrandomized cohort study.

Ninety-Day Readmission in Elective Revision Lumbar Fusion Surgery in the Inpatient Setting

STUDY DESIGN

Retrospective review.

OBJECTIVES

(1) Identify the 90-day rate of readmission following revision lumbar fusion, (2) identify independent risk factors associated with increased rates of readmission within 90 days, (3) and identify the hospital costs associated with revision lumbar fusion and subsequent readmission within 90 days.

METHODS

Utilizing 2014 data from the Nationwide Readmissions Database, patients undergoing elective revision lumbar fusion were identified. With this sample, multivariate logistic regression was utilized to identify independent predictors of readmission within 90 days. An analysis of total hospital costs was also conducted.

RESULTS

In 2014, an estimated 14 378 patients underwent elective revision lumbar fusion. The readmission rate at 90 days was 3.1% (n = 446). Diabetes with chronic complications was the only comorbidity found to carry significantly increased odds of readmission. Surgical complications such as deep venous thrombosis, surgical wound disruption, hematoma, and pneumonia (experienced during the index admission) were also independent predictors of readmission. Anterior approaches were associated with increased odds of readmission. The most common related diagnoses on readmission were hardware issues, postoperative infection, and disc herniation. Readmissions were associated with an average of $96 152 in increased hospital costs per patient compared with those not readmitted.

CONCLUSION

Relevant patient comorbidities and surgical complications were associated with increased readmission within 90 days. Readmission within 90 days was associated with significant increases in hospital costs.

Risk Factors for 90-day Readmissions With Fluid and Electrolyte Disorders Following Posterior Lumbar Fusion

STUDY DESIGN

Retrospective cohort study of the 2012 to 2014 Healthcare Cost and Utilization Project Nationwide Readmissions Database.

OBJECTIVE

To identify risk factors for 30- and 90-day readmission due to fluid and electrolyte disorders following posterior lumbar fusion.

SUMMARY OF BACKGROUND DATA

Thirty- and 90-day readmission rates are important quality and outcome measures for hospitals and physicians. These measures have been tied to financial penalties for abnormally high rates of readmission. Furthermore, complex and high cost surgeries have been increasingly reimbursed in the form of bundled disease resource group payments, where any treatment within 90-day postdischarge is covered within the original bundled payment scheme.

METHODS

A total of 65,121 patients in the Healthcare Cost and Utilization Project Nationwide Readmissions Database met our inclusion criteria, of which 1128 patients (1.7%) were readmitted within 30 days, and 1669 patients (2.6%) were readmitted within 90 days due to fluid and electrolyte abnormalities. A bivariate analysis was performed to compare baseline characteristics between patients readmitted with fluid and electrolyte disorders and the remainder of the cohort. A multivariate regression analysis was then performed to identify independent risk factors for readmission due to fluid and electrolyte disorders at 30 and 90 days.

RESULTS

The strongest independent predictors of 30-day readmissions were age ≥80 years, age 65 to 79 years, age 55 to 64 years, liver disease, and drug use disorder. The five strongest predictors of 90-day readmissions were age ≥80 years, age 65 to 79 years, age 55 to 64 years, liver disease, and fluid and electrolyte disorders.

CONCLUSION

Patients with baseline liver disease, previously diagnosed fluid and electrolyte disorders, age older than 55 years, or drug use disorders are at higher risk for readmissions with fluid and electrolyte disorders following posterior lumbar fusion. Close monitoring of fluid and electrolyte balance in the perioperative period is essential to decrease complications and reduce unplanned readmissions.

LEVEL OF EVIDENCE

3.

Black Race as a Social Determinant of Health and Outcomes After Lumbar Spinal Fusion Surgery: A Multistate Analysis, 2007 to 2014

STUDY DESIGN

A retrospective analysis of patient hospitalization and discharge records.

OBJECTIVE

To examine the association between race and inpatient postoperative complications following lumbar spinal fusion surgery.

SUMMARY OF BACKGROUND DATA

Racial disparities in healthcare have been demonstrated across a range of surgical procedures. Previous research has identified race as a social determinant of health that impacts outcomes after lumbar spinal fusion surgery. However, these studies are limited in that they are outdated, contain data from a single institution, analyze small limited samples, and report limited outcomes. Our study aims to expand and update the literature examining the association between race and inpatient postoperative complications following lumbar spine surgery.

METHODS

We analyzed 267,976 patient discharge records for inpatient lumbar spine surgery using data from the Healthcare Cost and Utilization Project's State Inpatient Databases for California, Florida, New York, Maryland, and Kentucky from 2007 through 2014. We used unadjusted bivariate analysis, adjusted multivariable, and stratified analysis to compare patient demographics, present-on-admission comorbidities, hospital characteristics, and complications by categories of race/ethnicity.

RESULTS

Black patients were 8% and 14% more likely than white patients to experience spine surgery specific complications (adjusted odds ratios [aOR]: 1.08, 95% confidence interval [CI]: 1.03-1.13) and general postoperative complications (aOR: 1.14, 95% CI: 1.07-1.20), respectively. Black patients, compared with white patients, also had increased adjusted odds of 30-day readmissions (aOR: 1.13, 95% CI: 1.07-1.20), 90-day readmissions (aOR: 1.07, 95% CI: 1.02-1.13), longer length of stay (LOS) (adjusted Incidence Rate Ratio: 1.15, 95% CI: 1.14-1.16), and higher total charges (adjusted Incidence Rate Ratio: 1.08, 95% CI: 1.07-1.09).

CONCLUSION

Our findings demonstrate that black patients, as compared with white patients, are more likely to have postoperative complications, longer postoperative lengths of stay, higher total hospital charges, and increased odds of 30- and 90-day readmissions following lumbar spinal fusion surgery.

LEVEL OF EVIDENCE

4.

Cost-effectiveness Applications of Patient-reported Outcome Measures (PROMs) in Spine Surgery

Because of the rising health care costs in the United States, there has been a focus on value-based care and improving the cost-effectiveness of surgical procedures. Patient-reported outcome measures (PROMs) can not only give physicians and health care providers immediate feedback on the well-being of the patients but also be used to assess health and determine outcomes for surgical research purposes. Recently, PROMs have become a prominent tool to assess the cost-effectiveness of spine surgery by calculating the improvement in quality-adjusted life years (QALY). The cost of a procedure per QALY gained is an essential metric to determine cost-effectiveness in universal health care systems. Common patient-reported outcome questionnaires to calculate QALY include the EuroQol-5 dimensions, the SF-36, and the SF-12. On the basis of the health-related quality of life outcomes, the cost-effectiveness of various spine surgeries can be determined, such as cervical fusions, lumbar fusions, microdiscectomies. As the United States attempts to reduce costs and emphasize value-based care, PROMs may serve a critical role in spine surgery moving forward. In addition, PROM-driven QALYs may be used to analyze novel spine surgical techniques for value-based improvements.

Preoperative and Postoperative Spending Among Working-Age Adults Undergoing Posterior Spinal Fusion Surgery for Degenerative Disease

OBJECTIVE

To investigate the health care resource utilization and the associated 6 months preoperative and 6 months postoperative spending among patients undergoing posterior lumbar fusion.

METHODS

We retrospectively reviewed a private insurance claims database for patients who underwent single-level posterior spinal fusion from January 2011 to December 2015. Outpatient health services, prescription pain medications, and inpatient admissions were assessed.

RESULTS

Among 25,401 patients (mean age, 52 years; 58% female) in the final cohort, median spending during the period from 6 months before surgery to 6 months after surgery was $60,714 (interquartile range [IQR], $46,961-$79,892)/patient. Preoperative spending accounted for 7% ($121 million) of the total costs, and postoperative spending accounted for 8% ($135 million). Median preoperative spending was $3566 (IQR, $2144-$5857) per patient, with imaging accounting for the highest proportion (33%) of preoperative spending. In the 6 months period preceding surgery, 46% patients received injections and 47% received physical therapy. The median postoperative spending was $1954/patient (IQR, $735-$4416). Total postoperative spending was significantly higher among those not discharged home (median, $7525; IQR, $6779-$19,602) compared with those discharged home (median, $1617/patient; IQR, $648-$4033) and home with home care services (median, $2921; IQR, $1406-$5662) (P < 0.001).

CONCLUSIONS

Unplanned readmission after posterior spinal fusion was the highest contributor to postoperative spending and the second highest contributor to overall costs. Understanding factors that contribute to the costs in the preoperative and postoperative period in patients undergoing single-level posterior lumbar fusion for degenerative pathology is essential to identify targets for cost containment.

Risk Factors Associated With 90-Day Readmissions After Degenerative Lumbar Fusion: An Examination of the Michigan Spine Surgery Improvement Collaborative (MSSIC) Registry

BACKGROUND

Most studies have evaluated 30-d readmissions after lumbar fusion surgery. Evaluation of the 90-d period, however, allows a more comprehensive assessment of factors associated with readmission.

OBJECTIVE

To assess the reasons and risk factors for 90-d readmissions after lumbar fusion surgery.

METHODS

The Michigan Spine Surgery Improvement Collaborative (MSSIC) registry is a prospective, multicenter, and spine-specific database of patients surgically treated for degenerative disease. MSSIC data were retrospectively analyzed for causes of readmission, and independent risk factors impacting readmission were found by multivariate logistic regression.

RESULTS

Of 10 204 patients who underwent lumbar fusion, 915 (9.0%) were readmitted within 90 d, most commonly for pain (17%), surgical site infection (16%), and radicular symptoms (10%). Risk factors associated with increased likelihood of readmission were other race (odds ratio [OR] 1.81, confidence interval [CI] 1.22-2.69), coronary artery disease (OR 1.57, CI 1.25-1.96), ≥4 fused levels (OR 1.41, CI 1.06-1.88), diabetes (OR 1.34, CI 1.10-1.63), and surgery length (OR 1.09, CI 1.03-1.16). Factors associated with decreased risk were discharge to home (OR 0.63, CI 0.51-0.78), private insurance (OR 0.79, CI 0.65-0.97), ambulation same day of surgery (OR 0.81, CI 0.67-0.97), and spondylolisthesis diagnosis (OR 0.82, CI 0.68-0.97). Of those readmitted, 385 (42.1%) patients underwent another surgery.

CONCLUSION

Ninety-day readmission occurred in 9.0% of patients, mainly for pain, wound infection, and radicular symptoms. Increased focus on postoperative pain may decrease readmissions. Among factors impacting the likelihood of 90-d readmission, early postoperative ambulation may be most easily modifiable. Optimization of preexisting medical conditions could also potentially decrease readmission risk.

Patient Factors Affecting Emergency Department Utilization and Hospital Readmission Rates After Primary Anterior Cervical Discectomy and Fusion: A Review of 41,813 cases

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

To identify preoperative risk factors for emergency department (ED) visit and unplanned hospital readmission after primary anterior cervical discectomy and fusion (ACDF) at 30 and 90 days.

SUMMARY OF BACKGROUND DATA

Limited data exist to identify factors associated with ED visit or readmission after primary ACDF within the first 3 months following surgery.

METHODS

Patients undergoing ACDF from 2005 to 2012 were identified in the Statewide Planning and Research Cooperative System database. Multivariable regression models were created based on patient-level and surgical characteristics to identify independent risk factors for hospital revisit.

RESULTS

Of 41,813 patients identified, 2514 (6.0%) returned to the ED within 30 days of discharge. Risk factors included age < 35, black race (OR 1.19), Charlson Comorbidity index score > 1, length of stay (LOS) greater than 1 day (OR 1.23), and fusion of > 2 levels (OR 1.17). Four thousand six hundred nine (11.0%) patients returned to the ED within 90 days. Risk factors mirrored those at 30 days. Patients having private insurance or those discharged to rehab were less likely to present to the ED. One thousand three hundred ninety-four (3.3%) patients were readmitted by 30 days. Risk factors included male sex, Medicare, or Medicaid insurance (OR 1.71 and 1.79 respectively), Charlson comorbidity index > 1, discharge to a skilled nursing facility (OR 2.90), infectious/pathologic (OR 3.296), or traumatic (OR 1.409) surgical indication, LOS > 1 day (OR 1.66), or in-hospital complication. 2223 (5.3%) patients were readmitted by 90 days. Risk factors mirrored those at 30 days. No differences in readmission were seen based on race or number of levels fused. Patients aged 18 to 34 were less likely to be readmitted versus patients older than 35.

CONCLUSION

Insurance status, comorbidities, and LOS consistently predicted an unplanned hospital visit at 30 and 90 days. Although nondegenerative surgical indications and in-hospital complications did not predict ED visits, these factors increased the risk for readmission.

LEVEL OF EVIDENCE

3.

90-day Readmission in Elective Primary Lumbar Spine Surgery in the Inpatient Setting: A Nationwide Readmissions Database Sample Analysis

STUDY DESIGN

Secondary analysis of a large administrative database.

OBJECTIVE

The objectives of this study are to: 1) identify the incidence and cause of 90-day readmissions following primary elective lumbar spine surgery, 2) offer insight into potential risk factors that contribute to these readmissions, and 3) quantify the cost associated with these readmissions.

SUMMARY OF BACKGROUND DATA

As bundled-payment models for the reimbursement of surgical services become more popular in spine, the focus is shifting toward long-term patient outcomes in the context of 90-day episodes of care. With limited data available on national 90-day readmission statistics available, we hope to provide evidence that will aid in the development of more cost-effective perioperative care models.

METHODS

Using ICD-9 coding, we identified all patients 18 years of age and older in the 2014 Nationwide Readmissions Database (NRD) who underwent an elective, inpatient, primary lumbar spine surgery. Using multivariate logistic regression, we identified independent predictors of 90-day readmission while controlling for a multitude of confounding variables and completed a comparative cost analysis.

RESULTS

We identified 169,788 patients who underwent a primary lumbar spine procedure. In total 4268 (2.5%) were readmitted within 90 days. There was no difference in comorbidity burden between cohorts (readmitted vs. not readmitted) as quantified by the Elixhauser Comorbidity index. Independent predictors of increased odds of 90-day readmission were: anemia, uncomplicated diabetes and diabetes with chronic complications, surgical wound disruption and acute myocardial infarction at the time of the index admission, self-pay status, and an anterior surgical approach. Implant complications were identified as the primary related cause of readmission. These readmissions were associated with a significant cost increase.

CONCLUSION

There are clearly identifiable risk factors that increase the odds of hospital readmission within 90 days of primary lumbar spine surgery. An overall 90-day readmission rate of 2.5%, while relatively low, carries significantly increased cost to both the patient and hospital.

LEVEL OF EVIDENCE

3.

Risk factors for 90-day reoperation and readmission after lumbar surgery for lumbar spinal stenosis

OBJECTIVES

The objective of this study was to evaluate the incidence and risk factors for 90-day readmission and reoperation after elective surgery for lumbar spinal stenosis (LSS).

METHODS

The authors performed a retrospective consecutive cohort analysis of patients undergoing posterior lumbar decompression with or without fusion for LSS with claudication from January 2014 through December 2015.

RESULTS

Data were collected on 1592 consecutive patients. The mean age at surgery was 67.4 ± 10.1 years and 45% of patients were female. The 90-day reoperation rate was 4.7%, and 69.3% of the reoperations occurred within the first 30 days. The 90-day readmission rate was 7.2%. Multivariable analysis showed that postoperative development of a surgical site infection (SSI; odds ratio [OR] 14.09, 95% confidence interval [CI] 7.86–25.18), acute kidney injury (AKI; OR 6.76, 95% CI 2.39–19.57), and urinary tract infection (UTI; OR 3.96, 95% CI 2.43–6.37), as well as a history of congestive heart failure (CHF; OR 3.03, 95% CI 1.69–5.28), were significant risk factors for readmission within 90 days. Male sex (OR 0.60, 95% CI 0.38–0.92) was associated with decreased odds for readmission. With regards to reoperation, development of SSI (OR 25.06, 95% CI 13.54–46.51), sepsis (OR 7.63, 95% CI 1.52–40.59), UTI (OR 2.54, 95% CI 1.31–4.76), and increased length of stay (LOS; OR 1.25, 95% CI 1.17–1.33) were found to be significant risk factors. A subsequent analysis found that morbid obesity (OR 6.99), history of coronary artery disease (OR 2.263), increased duration of surgery (OR 1.004), and LOS (OR 1.07) were significant risk factors for developing an SSI.

CONCLUSIONS

Overall, this study found rates of 4.7% and 7.2% for reoperation and readmission, respectively, within 90 days: 30.7% of the reoperations and 44.7% of the readmissions occurred beyond the first 30 days. A diagnosis of SSI, AKI, UTI, and history of CHF were significant factors for readmission, while male sex was associated with decreased odds for readmission. A diagnosis of SSI, sepsis, UTI, and increased LOS were found to be significant predictors for reoperation. Understanding 90-day complication rates is imperative because there has been increased discussion and healthcare policy extending the global postoperative window to 90 days. Current literature supports a readmission rate of 3%–9% after spine surgery. However, this literature either is limited to a 30-day window or does not stratify between different types of spine surgeries.

ABBREVIATIONS

AKI = acute kidney injury; BPH = benign prostate hyperplasia; CAD = coronary artery disease; CHF = congestive heart failure; CI = confidence interval; CMS = Centers for Medicare and Medicaid Services; COPD = chronic obstructive pulmonary disease; DM = diabetes mellitus; EBL = estimated blood loss; LOS = length of stay; LSS = lumbar spinal stenosis; OR = odds ratio; POUR = postoperative urinary retention; SSI = surgical site infection; UTI = urinary tract infection.

A validated preoperative score for predicting 30-day readmission after 1-2 level elective posterior lumbar fusion

PURPOSE

To develop a model to predict 30-day readmission rates in elective 1-2 level posterior lumbar spine fusion (PSF) patients.

METHODS

In this retrospective case control study, patients were identified in the State Inpatient Database using ICD-9 codes. Data were queried for 30-day readmission, as well as demographic and surgical data. Patients were randomly assigned to either the derivation or the validation cohort. Stepwise multivariate analysis was conducted on the derivation cohort to predict 30-day readmission. Readmission after posterior spinal fusion (RAPSF) score was created by including variables with odds ratio (OR) > 1.1 and p < 0.01; value assigned to each variable was based on the OR and calibrated to 100. Linear regression was performed between readmission rate and RAPSF score to test correlation in both cohorts.

RESULTS

There were 92,262 and 90,257 patients in the derivation and validation cohorts. Thirty-day readmission rates were 10.9% and 11.1%, respectively. Variables in RAPSF included: age, female gender, race, insurance, anterior approach, cerebrovascular disease, chronic pulmonary disease, congestive heart failure, diabetes, hemiplegia/paraplegia, rheumatic disease, drug abuse, electrolyte disorder, osteoporosis, depression, obesity, and morbid obesity. Linear regression between readmission rate and RAPSF fits the derivation cohort and validation cohort with an adjusted r² of 0.92 and 0.94, respectively, and a coefficient of 0.011 (p < 0.001) in both cohorts.

CONCLUSION

The RAPSF can accurately predict readmission rates in PSF patients and may be used to guide an evidence-based approach to preoperative optimization and risk adjustment within alternative payment models for elective spine surgery.

LEVEL OF EVIDENCE

3. These slides can be retrieved under Electronic Supplementary Material.

Analysis of Risk Factors Associated with Hospital Readmission Within 360 Days After Degenerative Lumbar Spine Surgery in Elderly Patients

OBJECTIVE

There is a paucity of studies on readmission rates in elderly patients over a period of 360 days after spinal surgery.

METHODS

We identified 1248 patients older than 70 years who underwent degenerative lumbar spinal surgery from November 2005 to April 2015. We reviewed the patients who were readmitted within 360 days and compared them by univariate and multivariate analysis with the nonreadmitted patients for each period of 0-30, 30-90, 90-180, and 180-360 days postoperatively to determine risk factors for hospital readmission.

RESULTS

A total of 1248 patients (733 female, 58.7%) were enrolled in the study. The number of readmitted patients was 37 (2.96%), 94 (7.53%), 145 (11.62%), 182 (14.58%), and 213 (17.07%) at 30, 90, 180, 270, and 360 days, respectively. Surgical site-related problems decreased gradually in the first 0-90 days and slightly increased after then. Non-surgical site-related problems gradually increased with time. Logistic multiple regression analysis showed that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low alanine aminotransferase level, high body mass index, and high platelet level were risk factors for readmission.

CONCLUSIONS

We found that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low aspartate aminotransferase level, high body mass index, and high platelet level were risk factors for readmission. As the postoperative observational period became longer, the reasons for readmission tended to be more related to non-surgical site-related problems than to surgical-related problems.

Short- and long-term readmission rates after infrainguinal bypass in a safety net hospital are higher than expected

OBJECTIVE

Readmission rates are expected to have an increasing effect on both the hospital bottom line and physician reimbursements. Safety net hospitals may be most vulnerable. We examined readmissions at 30 days, 90 days, and 1 year in a large safety net hospital to determine the magnitude and effect of short- and long-term readmission rates after lower extremity infrainguinal bypass in this setting.

METHODS

All nonemergent extremity infrainguinal bypass performed at a large safety net hospital between 2008 and 2016 were identified. Patient demographic, social, clinical, and procedural details were extracted from the electronic medical record. An analysis of patients readmitted at 30 days, 90 days, and 1 year was completed to determine the details of the readmission.

RESULTS

A total of 350 patients undergoing extremity infrainguinal bypass were identified. The most frequent indication was tissue loss (57%), followed by claudication (25.6%), and rest pain (17.4%). Patient insurance carriers included Medicare (61.7%), Medicaid (25.4%), and private (13%). The distal target was the popliteal and tibial artery in 52.6% and 47.4% cases, respectively. The majority of bypasses used autologous vein (73.1%). In-hospital complications included pulmonary complications (4.3%), urinary tract infection (3.1%), acute renal failure (2%), graft occlusion (2%), myocardial infarction (1.7%), bleeding (1.4%), surgical wound complications (1.1%), and stroke (0.9%). The 30-day readmission rate was 30% with the most common reasons for readmission being surgical wound complications, nonsurgical foot/leg wounds, nonextremity infectious causes, cardiac ischemia, and congestive heart failure. The 90-day readmission rate was 49.4% and the most common reasons for readmission from 31 to 90 days were nonsurgical foot/leg wounds, graft complications, surgical wound complications, cardiac ischemia, and contralateral leg morbidity. The readmission rate within 1 year was 72.2%. Readmission causes from 91 days to 1 year included graft complications, contralateral leg morbidity, nonextremity infectious, nonsurgical foot/leg wounds, cardiac ischemia, and congestive heart failure. A tibial bypass target was associated with 30-day (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.06-2.69; P = .029) and 90-day (OR, 1.77; 95% CI, 1.14-2.74, P = .011) readmission. Nonprivate insurance (OR, 2.31; 95% CI, 1.17-4.57, P = .016), and critical limb ischemia (OR, 1.77; 95% CI, 1.14-2.74; P = .035) were associated with 1-year readmission.

CONCLUSIONS

Short- and long-term readmission rates in a safety net setting are high. The 30-day rates in this study are higher than historically reported. This data sets baseline rates for 90-day and 1-year readmission for future analyses. Although the majority of short-term readmissions are related to the index procedure, long-term readmission rates are more frequently related to systemic comorbidities. Targeted patient interventions aimed at preventing the most common reasons for readmission may improve readmission rates, particularly among patients with nonprivate insurance. However, other risk factors, such as tibial target, may not be modifiable and a higher readmission rate may need to be accepted in this population.