Patient-specific factors affecting hospital costs in lumbar spine surgery

Lumbar Laminotomy: Variables Affecting 90-day Overall Reimbursement

INTRODUCTION

Lumbar laminotomy/diskectomy is a common procedure performed to address radiculopathy that persists despite conservative treatment. Understanding cost/reimbursement variability and its drivers has the potential to help optimize related healthcare delivery. The goal of this study was to assess variability and factors associated with reimbursement through 90 days after single-level lumbar laminotomy/diskectomy.

METHODS

Lumbar laminotomies/diskectomies were isolated from the 2010 to 2021 PearlDiver M151 data set. Exclusion criteria included patients younger than 18 years; other concomitant spinal procedures; and indications of trauma, oncologic, or infectious diagnoses. Patient, surgical, and perioperative data were abstracted. These variables were examined using a multivariable linear regression model with Bonferroni correction to determine factors independently correlated with reimbursement.

RESULTS

A total of 28,621 laminotomies/diskectomies were identified. The average ± standard deviation 90-day postoperative reimbursement was $9,453.83 ± 19,343.99 and, with a non-normal distribution, the median (inner quartile range) was $3,314 ($5,460). By multivariable linear regression, variables associated with greatest increase in 90-day postoperative reimbursement were associated with admission (with the index procedure [+$11,757.31] or readmission [+$31,248.80]), followed by insurance type (relative to Medicare, commercial +$4,183.79), postoperative adverse events (+$2,006.60), and postoperative emergency department visits (+$1,686.89) ( P < 0.0001 for each). Lesser associations were with Elixhauser Comorbidity Index (+$286.67 for each point increase) and age (-$24.65 with each year increase) ( P < 0.001 and P = 0.003, respectively).

DISCUSSION

This study assessed a large cohort of lumbar laminotomies/diskectomies and found substantial variations in reimbursement/cost to the healthcare system. The largest increase in reimbursement was associated with admission (with the index procedure or readmission), followed by insurance type, postoperative adverse events, and postoperative emergency department visits. These results highlight the need to balance inpatient versus outpatient surgeries while limiting postoperative readmissions to minimize the costs associated with healthcare delivery.

What Is the Evidence Surrounding the Cost-Effectiveness of Osteobiologic Use in ACDF Surgery? A Systematic Review of the Literature

STUDY DESIGN

This study constitutes a systematic review of the literature.

OBJECTIVE

The aim of this study was to identify and present all available studies that report on the costs of osteobiologics used in anterior cervical discectomy and fusion (ACDF).

METHODS

The literature was systematically reviewed to identify studies with specific inclusion criteria: (1) randomized controlled trials and observational studies, (2) in adult patients, (3) with herniated disc(s) or degenerative cervical spine disease, (4) reporting on either direct or indirect costs of using specific osteobiologics in an ACDF operation. (5) Only studies in English were included. The quality of the included studies was assessed using the MINORS and RoB 2.0 tools.

RESULTS

Overall, 14 articles were included; one randomized controlled trial and 13 observational studies. The most commonly used osteobiologics other than autograft/iliac crest bone graft (ICBG) were allograft and bone morphogenetic protein (BMP). None of the studies was reported to be industry-supported. There was considerable heterogeneity on the reported costs. Overall, most studies reported on surgery-related costs, such as anesthesia, operating room, surgical materials and surgeon's fee. Only two studies, both using allograft, reported the exact cost of the osteobiologic used (450 GBP, $700). Some of the studies reported on the cost of care during hospitalization for the surgical operation, such as radiology studies, emergency room costs, cardiologic evaluation, laboratory studies, pharmacy costs, and room costs. Only a few studies reported on the cost of follow-up, reoperation, and physical therapy and rehabilitation.

CONCLUSION

Based on the data of this current systematic review, no recommendations can be made regarding the cost-effectiveness of using osteobiologics in ACDF. Given the high costs of osteobiologics, this remains a topic of importance. The design of future studies on the subject should include cost effectiveness.

Assessment of a Private Payer Bundled Payment Model for Lumbar Decompression Surgery

INTRODUCTION

Although bundled payment models are well-established in Medicare-aged individuals, private insurers are now developing bundled payment plans. The role of these plans in spine surgery has not been evaluated. Our objective was to analyze the performance of a private insurance bundled payment program for lumbar decompression and microdiskectomy.

METHODS

A retrospective review was conducted of all lumbar decompressions in a private payer bundled payment model at a single institution from October 2018 to December 2020. 120-day episode of care cost data were collected and reported as net profit or loss regarding set target prices. A stepwise multivariable linear regression model was developed to measure the effect of patient and surgical factors on net surplus or deficit.

RESULTS

Overall, 151 of 468 (32.2%) resulted in a deficit. Older patients (58.6 vs. 50.9 years, P < 0.001) with diabetes (25.2% vs. 13.9%, P = 0.004), hypertension (38.4% vs. 28.4%, P = 0.038), heart disease (13.9% vs. 7.57%, P = 0.030), and hyperlipidemia (51.7% vs. 35.6%, P = 0.001) were more likely to experience a loss. Surgically, decompression of more levels (1.91 vs. 1.19, P < 0.001), posterior lumbar decompression (86.8% vs. 56.5%, P < 0.001), and performing surgery at a tertiary hospital (84.8% vs. 70.3%, P < 0.001) were more likely to result in loss. All readmissions resulted in a loss (4.64% vs. 0.0%, P < 0.001). On multivariable regression, microdiskectomy (β: $2,398, P = 0.012) and surgery in a specialty hospital (β: $1,729, P = 0.096) or ambulatory surgery center (β: $3,534, P = 0.055) were associated with cost savings. Increasing number of levels, longer length of stay, active smoking, and history of cancer, dementia, or congestive heart failure were all associated with degree of deficit.

CONCLUSIONS

Preoperatively optimizing comorbidities and using risk stratification to identify those patients who may safely undergo surgery at a facility other than an inpatient hospital may help increase cost savings in a bundled payment model of working-age and Medicare-age individuals.

Patient-specific Risk Factors Increase Episode of Care Costs After Lumbar Decompression

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To determine, which patient-specific risk factors increase total episode of care (EOC) costs in a population of Centers for Medicare and Medicaid Services beneficiaries undergoing lumbar decompression.

SUMMARY OF BACKGROUND DATA

Lumbar decompression is an effective option for the treatment of central canal stenosis or radiculopathy in patients unresponsive to nonoperative management. Given that elderly Americans are more likely to have one or more chronic medical conditions, there is a need to determine, which, if any, patient-specific risk factors increase health care costs after lumbar decompression.

METHODS

Care episodes limited to lumbar decompression surgeries were retrospectively reviewed on a Centers for Medicare and Medicaid Service reimbursement database at our academic institution between 2014 and 2019. The 90-day total EOC reimbursement payments were collected. Patient electronic medical records were then matched to the selected care episodes for the collection of patient demographics, medical comorbidities, surgical characteristics, and clinical outcomes. A stepwise multivariate linear regression model was developed to predict patient-specific risk factors that increased total EOC costs after lumbar decompression. Significance was set at P <0.05.

RESULTS

A total of 226 patients were included for analysis. Risk factors associated with increased total EOC cost included increased age (per year) (β = $324.70, P < 0.001), comorbid depression (β = $4368.30, P = 0.037), revision procedures (β = $6538.43, P =0.012), increased hospital length of stay (per day) (β = $2995.43, P < 0.001), discharge to an inpatient rehabilitation facility (β = $14,417.42, P = 0.001), incidence of a complication (β = $8178.07, P < 0.001), and readmission (β = $18,734.24, P < 0.001) within 90 days.

CONCLUSIONS

Increased age, comorbid depression, revision decompression procedures, increased hospital length of stay, discharge to an inpatient rehabilitation facility, and incidence of a complication and readmission within 90 days were all associated with increased total episodes of care costs.

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.

The Impact of Cognitive Impairment on Postoperative Complications After Spinal Surgery: A Matched Analysis

OBJECTIVE

The coprevalence of age-related comorbidities such as cognitive impairment and spinal disorders is increasing. No studies to date have assessed the postoperative spine surgery outcomes of patients with mild cognitive impairment (MCI) or severe cognitive impairment (dementia) compared with those without preexisting cognitive impairment.

METHODS

Using all-payer claims database, 235,123 persons undergoing either cervical or lumbar spine procedures between January 2010 and October 2020 were identified. Exact 1:1:1 matching based on baseline patient demographics and comorbidities was used to create a dementia group, MCI group, and control group without MCI/dementia (n = 3636). The primary outcome was the rate of any 30-day major postoperative complications. Secondary outcomes included the rates of revision surgery, readmission rates within 30 days, and health care costs within 1 year postoperatively.

RESULTS

Compared with the control group, patients with dementia had an 8-fold and 5.4-fold increase in all-cause 30-day complications after undergoing cervical and lumbar spine procedures, respectively. Similarly, patients with MCI had a 3.1-fold and 2.2-fold increase in all-cause 30-day complications, respectively. Patients with either MCI or dementia had increased rates of pneumonia and urinary tract infection after either spine procedure compared with control (P < 0.01). Odds of revision surgery were increased in the lumbar surgery cohort for dementia (3.43; 95% confidence interval, 1.69-6.95) and for MCI (2.41; 95% confidence interval, 1.14-5.05).

CONCLUSIONS

This is the first study to characterize the postoperative complications profile of patients with preexisting dementia or MCI undergoing cervical and lumbar spine surgery. Both dementia and MCI are associated with increased postoperative complications within 30 days.

Healthcare resource utilization and costs 2 years pre- and post-lumbar spine surgery for stenosis: a national claims cohort study of 22,182 cases

BACKGROUND CONTEXT

Improved understanding of the pre- and postoperative trends in costs and healthcare resource utilization (HCRU) is needed to better inform patient expectations and aid in the development of strategies to minimize the significant healthcare burden associated with lumbar spine surgery.

PURPOSE

Examine the time course of costs and HCRU in the 2 years preceding and following elective lumbar spine surgery for stenosis in a large national claims cohort.

STUDY DESIGN/SETTING

Retrospective analysis of an administrative claims database (IBM® Marketscan® Research Databases 2007-2015).

PATIENT SAMPLE

Adult patients undergoing elective primary single-level lumbar surgery for stenosis with at least 2 years of continuous health plan enrollment pre- and postoperatively.

OUTCOME MEASURES

Functional measures, including monthly rates of HCRU (15 categories), monthly gross covered payments (including payments made by the health plan and deductibles and coinsurance paid by the patient) overall, by HCRU category, and by spine versus non-spine-related.

METHODS

All available patients were utilized for analysis of HCRU. For analysis of payments, only patients on noncapitated health plans providing accurate financial information were analyzed. Payments were converted to 2015 United States dollars using the medical care component of the consumer price index. Trends in payments and HCRU were plotted on a monthly basis pre- and post-surgery and assessed with regression models. Relationships with demographics, surgical factors, and comorbidities were assessed with multivariable repeated measures generalized estimating equations.

RESULTS

Median monthly healthcare payments 2 years prior to surgery were $275 ($22, $868). Baseline HCRU at 2 years preoperatively was stable or only gradually rising (office visits, prescription drug use), but began an increasingly steep rise in many categories 6 to 12 months prior to surgery. Monthly payments began an increasingly steep rise 6 months prior to surgery, reaching a peak of $1,402 ($634, $2,827) in the month prior to surgery. This was driven by an increase in radiology, office visits, PT, injections, prescription medications, ER encounters, and inpatient admissions. Payments dropped dramatically immediately following surgery. Over the remainder of the 2 years, the median total payments declined only slightly, as a continued decline in spine-related payments was offset by gradually increased non-spine related payments as patients aged. By 2 years postoperatively, the percentage of patients using PT and injections returned to within 1% of the baseline levels observed 2 years preoperatively; however, spine-related prescription medication use remained elevated, as did other categories of HCRU (radiology, office visits, lab/diagnostic services, and also rare events such as inpatient admissions, ER encounters, and SNF/IRF). Patients with a fusion component to their surgeries had higher payments and HCRU preoperatively, and this did not resolve postoperatively. Variations in payments and HCRU were also evident among plan types, with patients on comprehensive medical plans-predominantly employer-sponsored supplemental Medicare coverage-utilizing more inpatient, ER, and inpatient rehabilitation & skilled nursing facilities. Patients on high-deductible plans had fewer payments and HCRU across all categories; however, we are unable to distinguish whether this is because they used fewer of these services or if they were paying for these services out of pocket without submitting to the payer. By 2 years postoperatively, 51% of patients had no spine-related monthly payments, while 33% had higher and 16% had lower monthly payments relative to 2 years preoperatively.

CONCLUSIONS

This is the first study to characterize time trends in direct healthcare payments and HCRU over an extended period preceding and following spine surgery. Differences among plan types potentially highlight disparities in access to care and plan-related financial mediators of patients' healthcare resource utilization.

Risk Factors for 30-day and 90-day Readmission After Lumbar Decompression

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess readmission rates and risk factors for 30-day and 90-day readmission after elective lumbar decompression at a single institution.

SUMMARY OF BACKGROUND DATA

Hospital readmission is an undesirable aspect of interventional treatment. Studies evaluating readmissions after elective lumbar decompression typically analyze national databases, and therefore have several drawbacks inherent to their macroscopic nature that limit their clinical utility.

METHODS

Patients undergoing primary one- to four-level lumbar decompression surgery were retrospectively identified. Demographic, surgical, and readmission data within "30-days" (0-30 days) and "90-days" (31-90 days) postoperatively were extracted from electronic medical records. Patients were categorized into four groups: (1) no readmission, (2) readmission during the 30-day or 90-day postoperative period, (3) complication related to surgery, and (4) Emergency Department (ED)/Observational (OBs)/Urgent (UC) care.

RESULTS

A total of 2635 patients were included. Seventy-six (2.9%) were readmitted at some point within the 30- (2.3%) or 90-day (0.3%) postoperative periods. Patients in the pooled readmitted group were older (63.1 yr, P  < 0.001), had a higher American Society of Anesthesiologists (ASA) grade (31.2% with ASA of 3, P = 0.03), and more often had liver disease (8.1%, P = 0.004) or rheumatoid arthritis (12.0%, P = 0.02) than other cohorts. A greater proportion of 90-day readmissions and complications had surgical-related diagnoses or a diagnosis of recurrent disc herniation than 30-day readmissions and complications (66.7% vs. 44.5%, P = 0.04 and 33.3% vs. 5.5%, P < 0.001, respectively). Age (Odds ratio [OR]: 1.02, P = 0.01), current smoking status (OR: 2.38, P < 0.001), longer length of stay (OR: 1.14, P < 0.001), and a history of renal failure (OR: 2.59, P = 0.03) were independently associated with readmission or complication.

CONCLUSION

Increased age, current smoking status, hospital length of stay, and a history of renal failure were found to be significant independent predictors of inpatient readmission or complication after lumbar decompression.

Variations in LOS and its main determinants overtime at an academic spinal care center from 2006-2019

Objectives

Efforts to safely reduce hospital LOS while maintaining quality outcomes and patient satisfaction are paramount. The primary goal of this study was to assess trends in LOS at a high-volume quaternary care spine center. Secondary goals were to assess trends in factors most associated with prolonged LOS.

Methods

This is a prospective study of all consecutive patients admitted from January 2006 to December 2019. Data included demographics, diagnostic category (degenerative, oncology, deformity, trauma, other), LOS (mean, median, interquartile range, standard deviation, defined as days from admission to discharge), and in-hospital adverse events.

Results

A total of 13,493 patients were included. Overall LOS has not changed over time with an overall median of 6.3 days (p = 0.451). Median LOS significantly increased for patients treated for degenerative pathology from 2.2 days in 2006 to 3.2 days in 2019 (p = 0.019). LOS has not changed for patients treated for deformity (overall median 6.8 days, p = 0.411), oncology (overall median 11.0 days, p = 0.051), or trauma (overall median 11.8 days, p = 0.582). Emergency admissions increased 3.2%/year for degenerative pathologies (p =  < 0.001). Mean age has increased from 48.4 years in 2006 to 58.1 years in 2019 (p =  < 0.001). This trend was observed in the deformity, degenerative and trauma group, not for patients treated for oncological disease. More adverse events were significantly associated with increasing age.

Conclusion

This is the first North American study to comprehensively analyze trends in LOS for spinal surgery overtime in an academic center. Overall, LOS has not changed from 2006–2019. Various factors that influence LOS appear to have balanced each other. It may also be explained by the changing epidemiology of both elective and emergency surgeries. These findings provide opportunities for intervention and improvement, targeted at the geriatric population, to reduce length of hospitalization.

Costs associated with potentially unnecessary postoperative healthcare encounters after lumbar spine surgery

BACKGROUND CONTEXT

Excessive use of postoperative imaging after lumbar surgery has been documented, becoming a target for cutting costs. This must be balanced with the patient's need for information and allay their postoperative concerns.

PURPOSE

To determine the incidence and associated costs of patient interactions with the healthcare system, outside the standard follow up routine, in the first postoperative year.

STUDY DESIGN

Retrospective longitudinal cohort.

PATIENT SAMPLE

Consecutive series of 200 patients who underwent lumbar fusions from 2018 to 2019 from a multi-surgeon single tertiary spine center.

OUTCOME MEASURES

All healthcare encounters: phone calls, office and emergency department visits, and additional testing METHODS: A consecutive series of 200 patients who underwent lumbar fusions from 2018 to 2019 were identified. All non-routine healthcare encounters: phone calls, office and emergency department visits, and additional testing were collected. Direct costs for all healthcare services were determined using the Medicare Allowable rates. Indirect costs were determined using local, median income, length of office visits, and distance from the clinic to the patient's home.

RESULTS

Of 200 patients, 14 with thoracic fusion were excluded. The mean age of the 186 included patients was 58.26 years and 85 (46%) were male. Forty-seven percent (87/186) had only routine postoperative visits and 24 had revision surgery. Seventy-five patients made a total of 102 phone calls, 55 office visits, leading to 38 diagnostic studies none of which led to an additional intervention. Using Medicare Allowable rates, the mean direct cost was $776 per patient and the using a median income of $16/h the mean indirect cost was $124 per patient. There were no differences in the baseline characteristics among the patients who only had routine post-op encounters, had non-routine encounters or had a repeat surgery.

CONCLUSIONS

Forty percent of the patients undergoing lumbar surgery had a healthcare encounter outside their routine follow up that did not result in additional intervention after their index operation. These potentially unnecessary encounters create additional cost and inconvenience to both the patient and healthcare system. Providing patient reassurance is important and providers should identify ways to reduce associated costs through patient education, virtual visits, or new technologies to monitor patient's postoperative progress.

The Impact of ASA Status on Cost of Care and Length of Stay Following Posterior Cervical Decompression and Fusion

BACKGROUND

Increasing numbers of posterior cervical decompression and fusion (PCDF) over the past decade have raised the prospect of bundled payment plans. The American Society of Anesthesiologists (ASA) Physical Status Classification system may enable accurate estimation of healthcare costs, length of stay, and other postoperative outcomes in PCDF patients.

OBJECTIVE

To evaluate correlations between ASA and postoperative outcomes, length of stay (LOS), and healthcare costs in patients undergoing PCDF.

METHODS

971 patients that underwent PCDF between 2008 and 2016 at a single institution were evaluated by low (I and II) versus high (III and IV) ASA. Demographics were compared using univariate analysis. Cost of care, LOS and postoperative complications were compared using multivariable logistic and linear regression, controlling for gender, age, length of surgery and number of segments fused.

RESULTS

The high ASA cohort had greater mean age (62 vs. 55, p<0.0001) and higher Elixhauser comorbidity index (ECI) scores (p<0.0001). ASA was independently associated with longer LOS (+2.1 days, CI: 1.3-2.9; p<0.0001) and higher cost (+$2,936, CI: $1,457-$4,415; p<0.0001). High ASA patients were more likely to have a non-home discharge (3.9, 95% CI 2.8-5.6, p<0.0001), delayed extubation (3.2, 95% CI 1.4-7.3, p=0.006), ICU stay (2.4, 95% CI 1.5-3.7, p=0.0001), in-hospital complications (1.5, 95% CI 1.0-2.2, p=0.03) and 30-day (3.2, 95% CI 1.5-6.8, p=0.003) and 90-day (3.2, 95% CI 1.8-5.7, p=0.0001) readmission.

CONCLUSIONS

High ASA is strongly associated with increased costs, LOS and adverse outcomes following PCDF. Therefore, ASA could be useful for preoperative prediction of these outcomes.

Reimbursement of Lumbar Decompression at an Orthopedic Specialty Hospital Versus Tertiary Referral Center

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to investigate the differences in Medicare reimbursement for one- to three-level lumbar decompression procedures performed at a tertiary referral center versus an orthopedic specialty hospital (OSH).

SUMMARY OF BACKGROUND DATA

Lumbar decompression surgery is one of the most commonly performed spinal procedures. Lumbar decompression also comprises the largest proportion of spinal surgery that has transitioned to the outpatient setting.

METHODS

Patients who underwent a primary one- to three- level lumbar decompression were retrospectively identified. Reimbursement data for a tertiary referral center and an OSH were compiled through Centers for Medicare and Medicaid Services. Demographic data, surgical characteristics, and time cost data were collected through chart review. Multivariate regression models were used to determine independent factors associated with total episode of care cost, operating room (OR) time, procedure time, and length of stay (LOS), and to determine independent predictors of having the decompression performed at the OSH.

RESULTS

Total episode of care, facility, and non-facility payments were significantly greater at the tertiary referral center than the OSH, as were OR time for one- to three-level procedures, procedure time of all pooled levels, and LOS for one- and two-level procedures. Three-level procedure was independently associated with increased OR time, procedure time, and LOS. Age and two-level procedure were also associated with increased LOS. Procedure at the OSH was associated with decreased OR time and LOS. Charlson Comorbidity Index was a negative predictor of decompression being performed in the OSH setting.

CONCLUSION

Significant financial savings to health systems can be expected when performing lumbar decompression surgery at a specialty hospital as opposed to a tertiary referral center. Patients who are appropriate candidates for surgery in an OSH can in turn expect faster perioperative times and shorter LOS.Level of Evidence: 3.

Predicting High-Value Care Outcomes After Surgery for Skull Base Meningiomas

BACKGROUND

Although various predictors of adverse postoperative outcomes among patients with meningioma have been established, research has yet to develop a method for consolidating these findings to allow for predictions of adverse health care outcomes for patients diagnosed with skull base meningiomas. The objective of the present study was to develop 3 predictive algorithms that can be used to estimate an individual patient's probability of extended length of stay (LOS) in hospital, experiencing a nonroutine discharge disposition, or incurring high hospital charges after surgical resection of a skull base meningioma.

METHODS

The present study used data from patients who underwent surgical resection for skull base meningiomas at a single academic institution between 2017 and 2019. Multivariate logistic regression analysis was used to predict extended LOS, nonroutine discharge, and high hospital charges, and 2000 bootstrapped samples were used to calculate an optimism-corrected C-statistic. The Hosmer-Lemeshow test was used to assess model calibration, and P < 0.05 was considered statistically significant.

RESULTS

A total of 245 patients were included in our analysis. Our cohort was mostly female (77.6%) and white (62.4%). Our models predicting extended LOS, nonroutine discharge, and high hospital charges had optimism-corrected C-statistics of 0.768, 0.784, and 0.783, respectively. All models showed adequate calibration (P>0.05), and were deployed via an open-access, online calculator: https://neurooncsurgery3.shinyapps.io/high_value_skull_base_calc/.

CONCLUSIONS

After external validation, our predictive models have the potential to aid clinicians in providing patients with individualized risk estimation for health care outcomes after meningioma surgery.

Drivers of Prolonged Hospitalization Following Spine Surgery: A Game-Theory-Based Approach to Explaining Machine Learning Models

BACKGROUND

Understanding the interactions between variables that predict prolonged hospital length of stay (LOS) following spine surgery can help uncover drivers of this risk in patients. This study utilized a novel game-theory-based approach to develop explainable machine learning models to understand such interactions in a large cohort of patients treated with spine surgery.

METHODS

Of 11,150 patients who underwent surgery for degenerative spine conditions at a single institution, 3,310 (29.7%) were characterized as having prolonged LOS. Machine learning models predicting LOS were built for each patient. Shapley additive explanation (SHAP) values were calculated for each patient model to quantify the importance of features and variable interaction effects.

RESULTS

Models using features identified by SHAP values were highly predictive of prolonged LOS risk (mean C-statistic = 0.87). Feature importance analysis revealed that prolonged LOS risk is multifactorial. Non-elective admission produced elevated SHAP values, indicating a clear, strong risk of prolonged LOS. In contrast, intraoperative and sociodemographic factors displayed bidirectional influences on risk, suggesting potential protective effects with optimization of factors such as estimated blood loss, surgical duration, and comorbidity burden.

CONCLUSIONS

Meticulous management of patients with high comorbidity burdens or Medicaid insurance who are admitted non-electively or spend clinically indicated time in the intensive care unit (ICU) during their hospitalization course may be warranted to reduce their risk of unanticipated prolonged LOS following spine surgery.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Utilization of the American Society of Anesthesiologists (ASA) classification system in evaluating outcomes and costs following deformity spine procedures

PURPOSE

Adult spinal deformity (ASD) has increased prevalence in aging populations. Due to the high cost of surgery, studies have evaluated risk factors that predict readmissions and poor outcomes. The American Society of Anesthesiologists (ASA) classification system has been applied to patients with ASD to assess preoperative health and assess the correlation between ASA class and postoperative complications. This study evaluates the relationship between ASA and complications, length of stay (LOS), and direct costs following spine deformity surgery.

METHODS

Patients undergoing spine deformity surgery at a single institution from 2008-2016 were included and stratified based upon ASA status. Primary outcomes included patient demographics, adjusted LOS, and cost of care. Secondary measures compared between cohorts included adverse events, non-home discharge, and readmission rates.

RESULTS

442 patients with ASD were included in this study. Higher ASA class was correlated with greater Elixhauser Comorbidity Index (ECI) scores (p < 0.0001) and older age (p < 0.0001). Univariate analysis showed longer LOS (p < 0.0001) and greater direct costs in patients with higher ASA class (p < 0.0001). Patients in ASA Class III or IV had the greatest incidence of ICU stay when compared to patients without systemic disease (p < 0.0001). Upon multivariable regression analysis, high ASA class was associated with higher rates of non-home discharge (OR 5.0, 95% CI 3.1-8.1). Direct costs were greater for higher ASA class (regression estimate =  + $9,666, p = 0.002).

CONCLUSION

This study demonstrates that ASA class is correlated with a more complicated postoperative hospital course, greater rates of non-home discharge, total direct costs in spine deformity patients.

Later Surgical Start Time Is Associated With Longer Length of Stay and Higher Cost in Cervical Spine Surgery

STUDY DESIGN

Retrospective study of a surgical cohort from a single, large academic institution.

OBJECTIVE

The aim of this study was to investigate associations between surgical start time, length of stay, cost, perioperative outcomes, and readmission.

SUMMARY OF BACKGROUND DATA

One retrospective study with a smaller cohort investigated associations between surgical start time and outcomes in spine surgery and found that early start times were correlated with shorter length of stay. No examinations of perioperative outcomes or cost have been performed.

METHODS

All patients undergoing anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF) were queried from a single institution from January 1, 2008 to November 30, 2016. Patients undergoing surgery that started between 12:00 AM and 6:00 AM were excluded due to their likely emergent nature. Cases starting before and after 2:00 PM were compared on the basis of length of stay and cost as the primary outcomes using multivariable logistic regression.

RESULT

The patients undergoing ACDF and PCDF were both similar on the basis of comorbidity burden, preoperative diagnosis, and number of segments fused. The patients undergoing ACDF starting after 2 PM had longer LOS values (adjusted difference of 0.65 days; 95% confidence interval [CI]: 0.28-1.03; P = 0.0006) and higher costs of hospitalization (adjusted difference of $1177; 95% CI: $549-$1806; P = 0.0002). Patients undergoing PCDF starting after 2 PM also had longer LOS values (adjusted difference of 1.19 days; 95% CI: 0.46-1.91; P = 0.001) and higher costs of hospitalization (adjusted difference of $2305; 95% CI: $826-$3785; P = 0.002).

CONCLUSION

Later surgical start time is associated with longer LOS and higher cost. These findings should be further confirmed in the spine surgical literature to investigate surgical start time as a potential cost-saving measure.

LEVEL OF EVIDENCE

3.

Adult Spinal Deformity Surgery in Patients With Movement Disorders: A Propensity-matched Analysis of Outcomes and Cost

STUDY DESIGN

This was a retrospective study using national administrative data from the MarketScan database.

OBJECTIVE

To investigate the complication rates, quality outcomes, and costs in a nationwide cohort of patients with movement disorders (MD) who undergo spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

Patients with MD often present with spinal deformities, but their tolerance for surgical intervention is unknown.

METHODS

The MarketScan administrative claims database was queried to identify adult patients with MD who underwent spinal deformity surgery. A propensity-score match was conducted to create two uniform cohorts and mitigate interpopulation confounders. Perioperative complication rates, 90-day postoperative outcomes, and total costs were compared between patients with MD and controls.

RESULTS

A total of 316 patients with MD (1.7%) were identified from the 18,970 undergoing spinal deformity surgery. The complication rate for MD patients was 44.6% and for the controls 35.6% (P = 0.009). The two most common perioperative complications were more likely to occur in MD patients, acute-posthemorrhagic anemia (26.9% vs. 20.8%, P < 0.05) and deficiency anemia (15.5% vs. 8.5%, P < 0.05). At 90 days, MD patients were more likely to be readmitted (17.4% vs. 13.2%, P < 0.05) and have a higher total cost ($94,672 vs. $85,190, P < 0.05). After propensity-score match, the overall complication rate remained higher in the MD group (44.6% vs. 37.6%, P < 0.05). 90-day readmissions and costs also remained significantly higher in the MD cohort. Multivariate modeling revealed MD was an independent predictor of postoperative complication and inpatient readmission. Subgroup analysis revealed that Parkinson disease was an independent predictor of inpatient readmission, reoperation, and increased length of stay.

CONCLUSION

Patients with MD who undergo spinal deformity surgery may be at risk of higher rate of perioperative complications and 90-day readmissions compared with patients without these disorders.

LEVEL OF EVIDENCE

3.

American Society of Anesthesiologists' Status Association With Cost and Length of Stay in Lumbar Laminectomy and Fusion: Results From an Institutional Database

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The objective of this study was to characterize the costs associated with American Society of Anesthesiologists (ASA) class, and to determine the extent to which ASA status is a predictor of increased cost and LOS following lumbar laminectomy and fusion (LLF).

SUMMARY OF BACKGROUND DATA

Spinal fusion accounts for the highest hospital costs of any surgical procedure performed in the United States, and ASA (American Society of Anesthesiologists) status is a known risk factor for cost and length of stay (LOS) in the orthopedic literature. There is a paucity of literature that directly addresses the influence of ASA status on cost and LOS following LLF.

METHODS

This is a retrospective cohort study of an institutional database of patients undergoing single-level LLF at an academic tertiary care facility from 2006 to 2016. Univariate comparisons were made using χ tests for categorical variables and t tests for continuous variables. Multivariate linear regression was utilized to estimate regression coefficients, and to determine whether ASA status is an independent risk factor for cost and LOS.

RESULTS

A total of 1849 patients met inclusion criteria. For every one-point increase in ASA score, intensive care unit (ICU) LOS increased by 0.518 days (P < 0.001), and hospital length of stay increased by 1.93 days (P < 0.001). For every one-point increase in ASA score, direct cost increased by $7474.62 (P < 0.001).

CONCLUSION

ASA status is a predictor of hospital LOS, ICU LOS, and direct cost. Consideration of the ways in which ASA status contributes to increased cost and prolonged LOS can allow for more accurate reimbursement adjustment and more precise targeting of efficiency and cost effectiveness initiatives.

LEVEL OF EVIDENCE

3.

Analysis of an overlapping surgery policy change on costs in a high-volume neurosurgical department

OBJECTIVE

Overlapping surgery remains a controversial topic in the medical community. Although numerous studies have examined the safety profile of overlapping operations, there are few data on its financial impact. The authors assessed direct hospital costs associated with neurosurgical operations during periods before and after a more stringent overlapping surgery policy was implemented.

METHODS

The authors retrospectively reviewed the records of nonemergency neurosurgical operations that took place during the periods from June 1, 2014, to October 31, 2014 (pre–policy change), and from June 1, 2016, to October 31, 2016 (post–policy change), by any of the 4 senior neurosurgeons authorized to perform overlapping cases during both periods. Cost data as well as demographic, surgical, and hospitalization-related variables were obtained from an institutional tool, the Value-Driven Outcomes database.

RESULTS

A total of 625 hospitalizations met inclusion criteria for cost analysis; of these, 362 occurred prior to the policy change and 263 occurred after the change. All costs were reported as a proportion of the average total hospitalization cost for the entire cohort. There was no significant difference in mean total hospital costs between the prechange and postchange period (0.994 ± 1.237 vs 1.009 ± 0.994, p = 0.873). On multivariate linear regression analysis, neither the policy change (p = 0.582) nor the use of overlapping surgery (p = 0.273) was significantly associated with higher total hospital costs.

CONCLUSIONS

A more restrictive overlapping surgery policy was not associated with a reduction in the direct costs of hospitalization for neurosurgical procedures.

Implications of anesthetic approach, spinal versus general, for the treatment of spinal disc herniation

OBJECTIVEHealthcare costs continue to escalate. Approaches to care that have comparable outcomes and complications are increasingly assessed for quality improvement and, when possible, cost containment. Efforts to identify components of care to reduce length of stay (LOS) have been ongoing. Spinal anesthesia (SA), for select lumbar spine procedures, has garnered interest as an alternative to general anesthesia (GA) that might reduce cost and in-hospital LOS and accelerate recovery. While clinical outcomes with SA or GA have been studied extensively, few authors have looked at the cost-analysis in relation to clinical outcomes. The authors' objectives were to compare the clinical perioperative outcomes of patients who received SA and GA, as well as the direct costs associated with each modality of care, and to determine which, in a retrospective analysis, can serve as a dominant procedural approach.METHODSThe authors retrospectively analyzed a homogeneous surgical population of 550 patients who underwent hemilaminotomy for disc herniation and who received either SA (n = 91) or GA (n = 459). All clinical and billing data were obtained via each patient's chart and the hospital's billing database, respectively. Additionally, the authors prospectively assessed patient-reported outcome measures for a subgroup of consecutively treated patients (n = 75) and compared quality-adjusted life year (QALY) gains between the two cohorts. Furthermore, the authors performed a propensity score-matching analysis to compare the two cohorts (n = 180).RESULTSDirect hospital costs for patients receiving SA were 40% higher, in the hundreds of dollars, than for patients who received GA (p < 0.0001). Furthermore, there was a significant difference with regard to LOS (p < 0.0001), where patients receiving SA had a considerably longer hospital LOS (27.6% increase in hours). Patients undergoing SA had more comorbidities (p = 0.0053), specifically diabetes and hypertension. However, metrics of complications, including readmission (p = 0.3038) and emergency department (ED) visits at 30 days (p = 1.0), were no different. Furthermore, in a small pilot group, QALY gains were statistically no different (n = 75, p = 0.6708). Propensity score-matching analysis demonstrated similar results as the univariate analysis: there was no difference between the cohorts regarding 30-day readmission (p = 1.0000); ED within 30 days could not be analyzed as there were no patients in the SA group; and total direct costs and LOS were significantly different between the two cohorts (p < 0.0001 and p = 0.0126, respectively).CONCLUSIONSBoth SA and GA exhibit the qualities of a good anesthetic, and the utilization of these modalities for lumbar spine surgery is safe and effective. However, this work suggests that SA is associated with increased LOS and higher direct costs, although these differences may not be clinically or fiscally meaningful.

What are the Rates, Reasons, and Risk Factors of 90-day Hospital Readmission After Lumbar Discectomy?: An Institutional Experience

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

To report the rate, reasons, and risk factors for 90-day readmissions after lumbar discectomy at an academic medical center.

SUMMARY OF BACKGROUND DATA

Several studies have reported complications and readmissions after spine surgery; however, only one previous study has focused specifically on lumbar discectomy. As the patient profile and morbidity of various spine procedures is different, focus on procedure-specific complications and readmissions will be beneficial.

MATERIALS AND METHODS

Patients who underwent lumbar discectomy for unrelieved symptoms of prolapsed intervertebral disk and had at least 90 days of follow-up at an academic institution (2013-2014) were included. Retrospective review of electronic medical record was performed to record demographic and clinical profile of patients. Details of lumbar discectomy, index hospital stay, discharge disposition, hospital readmission within 90 days, reason for readmission and treatment given have been reported. Risk factors for hospital readmission were analyzed by multivariate logistic regression analysis.

RESULTS

A total of 356 patients with a mean age of 45.0±13.8 years were included. The 90-day readmission rate was 5.3% (19/360) of which two-third patients were admitted within 30 days giving a 30-day readmission rate of 3.7% (13/356). The top 2 primary reasons for readmission included back and/or leg pain, numbness, or tingling (42.9%), and persistent cerebrospinal fluid leak or seroma (25.0%). On adjusted analysis, risk factors associated with higher risk of readmission included incidental durotomy [odds ratio (OR), 26.2; 95% confidence interval (CI), 5.3-129.9] and discharge to skilled nursing facility/inpatient rehabilitation (OR, 25.2; 95% CI, 2.7-235.2). Increasing age was a negative predictor of readmission (OR, 0.95; 95% CI, 0.91-0.99).

CONCLUSIONS

Incidental durotomy, younger age, and discharge to nursing facility were associated with higher risk of 90-day hospital readmission after lumbar discectomy. As compared with extensive spine procedures, patient comorbidity burden may not be as significant in predicting readmission after this relatively less invasive procedure.

Preoperative Chronic Opioid Therapy: A Risk Factor for Complications, Readmission, Continued Opioid Use and Increased Costs After One- and Two-Level Posterior Lumbar Fusion

STUDY DESIGN

Retrospective, economic analysis.

OBJECTIVE

To study patient profile associated with preoperative chronic opioid therapy (COT), and study COT as a risk factor for 90-day complications, emergency department (ED) visits, and readmission after primary one- to two-level posterior lumbar fusion (PLF) for degenerative spine disease. We also evaluated associated costs, risk factors, and adverse events related to long-term postoperative opioid use.

SUMMARY OF BACKGROUND DATA

Chronic opioid use is associated with poor outcomes and dependence after spine surgery. Risk factors, complications, readmissions, adverse events, and costs associated with COT in patients undergoing lumbar fusion are not entirely known. As providers look to reduce healthcare costs and improve outcomes, identification of modifiable risk factors is important.

METHODS

Commercial insurance data from 2007 to Q3-2015 was used to study preoperative opioid use in patients undergoing primary one- to two-level PLF. Ninety-day complications, ED visits, readmissions, 1-year adverse events, and associated costs have been described. Multiple-variable regression analyses were done to study preoperative COT patient profile and opioid use as a risk factor for complications and adverse events.

RESULTS

A total of 24,610 patients with a mean age of 65.6 ± 11.5 years were included. Five thousand five hundred (22.3%) patients had documented opioid use for more than 6 months before surgery, and 87.4% of these had continued long-term use postoperatively. On adjusted analysis, preoperative COT was found to be a risk factor for 90-day wound complications, pain diagnoses, ED visits, readmission, and continued use postoperatively. Postspinal fusion long-term opioid users had an increased utilization of epidural/facet joint injections, risk for revision fusion, and increased incidence of new onset constipation within 1 year postsurgery. The cost associated with increase resource use in these patients has been reported.

CONCLUSION

Preoperative COT is a modifiable risk factor for complications, readmission, adverse events, and increased costs after one- or two-level PLF.

LEVEL OF EVIDENCE

3.

Surgeon Reimbursement Relative to Hospital Payments for Spinal Fusion: Trends From 10-year Medicare Analysis

STUDY DESIGN

Retrospective, economic analysis.

OBJECTIVE

The aim of this study was to analyze the trend in hospital charge and payment adjusted to corresponding surgeon charge and payment for cervical and lumbar fusions in a Medicare sample population from 2005 to 2014.

SUMMARY OF BACKGROUND DATA

Previous studies have reported trends and variation in hospital charges and payments for spinal fusion, but none have incorporated surgeon data in analysis. Knowledge of the fiscal relationship between hospitals and surgeons over time will be important for stakeholders as we move toward bundled payments.

METHODS

A 5% Medicare sample was used to capture hospital and surgeon charges and payments related to cervical and lumbar fusion for degenerative disease between 2005 and 2014. We defined hospital charge multiplier (CM) as the ratio of hospital/surgeon charge. Similarly, the hospital/surgeon payment ratio was defined as hospital payment multiplier (PM). The year-wise and regional trend in patient profile, length of stay, discharge disposition, CM, and PM were studied for all fusion approaches separately.

RESULTS

A total of 40,965 patients, stratified as 15,854 cervical and 25,111 lumbar fusions, were included. The hospital had successively higher charges and payments relative to the surgeon from 2005 to 2014 for all fusions with an inverse relation to hospital length of stay. Increasing complexity of fusion such as for anterior-posterior cervical fusion had higher hospital reimbursements per dollar earned by the surgeon. There was regional variation in how much the hospital charged and received per surgeon dollar.

CONCLUSION

Hospital charge and payment relative to surgeon had an increasing trend despite a decreasing length of stay for all fusions. Although the hospital can receive higher payments for higher-risk patients, this risk is not reflected proportionally in surgeon payments. The shift toward value-based care with shared responsibility for outcomes and cost will likely rely on better aligning incentives between hospital and providers.

LEVEL OF EVIDENCE

3.

Distribution and Determinants of 90-Day Payments for Multilevel Posterior Lumbar Fusion: A Medicare Analysis

STUDY DESIGN

A retrospective, economic analysis.

OBJECTIVE

The objective of this article is to analyze the distribution of 90-day payments, sources of variation, and reimbursement for complications and readmissions for primary ≥3-level posterior lumbar fusion (PLF) from Medicare data. A secondary objective was to identify risk factors for complications.

SUMMARY OF BACKGROUND DATA

Bundled payments represent a single payment system to cover all costs associated with a single episode of care, typically over 90 days. The dollar amount spent on different health service providers and the variation in payments for ≥3-level PLF have not been analyzed from a bundled perspective.

MATERIALS AND METHODS

Administrative claims data were used to study 90-day Medicare (2005-2012) reimbursements for primary ≥3-level PLF for deformity and degenerative conditions of the lumbar spine. Distribution of payments, sources of variation, and reimbursements for managing complications were studied using linear regression models. Risk factors for complications were studied by stepwise multiple-variable logistic regression analysis.

RESULTS

Hospital payments comprised 73.8% share of total 90-day payment. Adjusted analysis identified several factors for variation in index hospital payments. The average 90-day Medicare payment for all multilevel PLFs without complications was $35,878 per patient. The additional average cost of treating complications with/without revision surgery within 90 days period ranged from $17,284 to $68,963. A 90-day bundle for ≥3-level PLF with readmission ranges from $88,648 (3 levels) to $117,215 (8+ levels). Rates and risk factors for complications were also identified.

CONCLUSIONS

The average 90-day payment per patient from Medicare was $35,878 with several factors such as levels of surgery, comorbidities, and development of complications influencing the cost. The study also identifies the risks and costs associated with complications and readmissions and emphasize the significant effect these would have on bundled payments (additional burden of up to 192% the cost of an average uncomplicated procedure over 90 days).

LEVEL OF EVIDENCE

Level 3.

A 90-day Bundled Payment for Primary Single-level Lumbar Discectomy/Decompression: What Does "Big Data" Say?

Episode-based bundling may become the major form of reimbursement for many elective spine procedures. As the amount for a 90-day episode of care is not known for a lumbar discectomy, we analyzed the previous reimbursements from Commercial payers (2007-Q2 2015), Medicare Advantage (2007-Q2 2015), and Medicare (2005-2012) for a primary single-level lumbar discectomy/decompression. Distribution of payments among various service providers was studied and a 90-day bundle was simulated. Depending on the payer type, the average facility costs constituted 59.7% to 73.6% of total payments, followed by surgeon's fees, which accounted for 13.7% to 18.5%. Postacute services made up 8.8% to 15.8% of the total reimbursement. Surgeries performed in the inpatient setting were significantly more expensive as compared with surgeries performed in the outpatient setting (P<0.01). The average 90-day bundle amount was estimated at $11,091, $6571, and $6239 for Commercial payers, Medicare Advantage, and Medicare, respectively. Overall, service providers in the Southern region were reimbursed the lowest from Commercial payers and Medicare, compared with other regions. Postacute services are not as major cost drivers after discectomy as after total joint arthroplasty or hip fracture repair.

Ninety-Day Reimbursements for Primary Single-Level Posterior Lumbar Interbody Fusion From Commercial and Medicare Data

STUDY DESIGN

Retrospective, economic analysis.

OBJECTIVE

To analyze the distribution of 90-day payments for a primary single-level posterior lumbar interbody fusion from Commercial payers and Medicare.

SUMMARY OF BACKGROUND DATA

Episode-based bundled payments aim to align incentives of all health care providers toward the common goal of high quality and economic health care. Understanding the evolving reimbursement models for spine surgery will require knowledge on existing payments, distribution, and variation. Also, it will help identify areas for cost reduction. This is currently not known for a primary single-level posterior lumbar interbody fusion.

METHODS

Administrative claims data were used to study reimbursements from Commercial payers (2007-Q3 2015), Medicare Advantage (2007-Q3 2015), and Medicare (2005-2012) for a primary single-level posterior lumbar interbody fusion. Distribution of payments among various service providers was studied. In addition to descriptive analysis, variation between regions and payers was studied by a one-way analysis of variance and post hoc Tukey test.

RESULTS

Average hospital costs comprise 74.2% to 77% of the total payments, followed by surgeon's fees which accounted for 12.8% to 13.7%. Overall burden of readmissions/revisions was 2.1% to 2.7%, but for the readmitted patient it constitutes 25% to 54% of the 90-day payment. Inpatient surgery had significantly higher facility costs than outpatient surgery (P = 0.02). The average 90-day payment amount was $51,465, $26,234, and $25,501 for Commercial payers, Medicare Advantage, and Medicare, respectively. There was some regional variation, however not consistent among different payers.

CONCLUSION

Hospital costs constitute the majority share of 90-day payments, which can be reduced by performing surgery in the outpatient setting. Reducing hospital costs and readmissions can lower the financial burden associated with this common spine procedure.

LEVEL OF EVIDENCE

3.

Cost Variation of Anterior Cervical Fusions in Elderly Medicare Beneficiaries

STUDY DESIGN

Retrospective database review.

OBJECTIVE

To determine how demographics and comorbid diagnoses influence hospital costs during admission for anterior cervical fusions (ACFs) in the elderly Medicare population.

SUMMARY OF BACKGROUND DATA

Elective ACFs to treat degenerative cervical pathology are extremely common within the elderly population. Although it is well known that every patient has a significantly different medical profile that guides treatment and postoperative care, little information is available regarding how hospital costs vary from patient to patient.

METHODS

Medicare records from the PearlDiver database (2011-2012) were retrospectively queried to select all 65- to 84-year-old patients who underwent primary, 1 to 2 level ACF (International Classification of Diseases, Ninth Revision, Clinical Modification: 81.02) for either cervical spondylosis or cervical disc disease. All patients with corpectomies, posterior cervical fusions, and all other same-day spine fusion surgeries were excluded. The primary outcome of this study was Medicare reimbursement from the full inpatient stay as associated with the selected International Classification of Diseases, Ninth Revision procedure code. The relative contributions of year, age, sex, region, myelopathy diagnosis, and various comorbidities to the total cost were determined with both univariate statistics and multivariate analysis. For all analyses, P < 0.001 was determined to be significant.

RESULTS

In total, 21,853 patients were selected for analysis. The average reimbursement for the full cohort was $13,648 ± $7306. On multivariate analysis, advanced age ($1083), diagnosis of myelopathy ($2150), diabetes mellitus ($1019), obesity ($651), congestive heart failure ($1523), chronic kidney disease ($1962), and chronic pulmonary disease ($489) were all factors that increased costs. Of note, sex, smoking history, and prior liver disease were not associated with changes in cost.

CONCLUSION

Medicare reimbursements provide a value means by which determinants of cost can be elucidated. Although multiple comorbidities, older age, and myelopathy diagnosis could be theorized to contribute to increased costs, there is still some uncertainty regarding their relative costs. These data are informative to practicing physicians as health care as a whole transitions to a more value-based approach.

LEVEL OF EVIDENCE

4.

Lumbar microdiscectomy as a day-case procedure: Scope for improvement?

BACKGROUND AND PURPOSE

There are no significant differences in outcomes between patients receiving inpatient and day-case lumbar microdiscectomy, but the latter is still underused in the NHS. Here we aimed to identify factors contributing to successful same-day discharge in day-case patients.

METHODS

This was a retrospective observational study of patients undergoing elective lumbar microdiscectomy between August 2012 and December 2014. Age, gender, day of surgery, distance to hospital, ASA grade, regular opiate use, smoking status, order on the operating list, and side and level of surgery were examined by logistic regression to assess their influence on same-day discharge.

RESULTS

28/95 (29.5%) patients were discharged on the day of surgery. Age (p = 0.041), ASA grade (p = 0.016), distance to hospital (p = 0.011), and position on the list (p = 0.004) were associated with day-case discharge by univariate analysis. ASA grade (p = 0.032; OR 0.176), distance to hospital (p = 0.003; OR 0.965), and position on the operating list (morning case; p = 0.011; OR 8.901) remained significant in multivariate analysis. Thirteen (13.7%) patients were identified who could have been managed as day cases had they been listed for morning operations.

CONCLUSIONS

Day-case lumbar microdiscectomy is viable when patients are carefully selected. Younger, fit patients living close to the hospital and operated on in the morning are more likely to be discharged on the same day. Knowledge of these factors while planning elective lists can help optimise bed space and improve spinal services.

Impact of obesity on complications and outcomes: a comparison of fusion and nonfusion lumbar spine surgery

OBJECTIVE Prior studies have shown obesity to be associated with higher complication rates but equivalent clinical outcomes following lumbar spine surgery. These findings have been reproducible across lumbar spine surgery in general and for lumbar fusion specifically. Nevertheless, surgeons seem inclined to limit the extent of surgery, perhaps opting for decompression alone rather than decompression plus fusion, in obese patients. The purpose of this study was to ascertain any difference in clinical improvement or complication rates between obese and nonobese patients following decompression alone compared with decompression plus fusion for lumbar spinal stenosis (LSS). METHODS The Quality Outcomes Database (QOD), formerly known as the National Neurosurgery Quality and Outcomes Database (N²QOD), was queried for patients who had undergone decompression plus fusion (D+F group) versus decompression alone (D+0 group) for LSS and were stratified by a body mass index (BMI) ≥ 30 kg/m² (obese) or < 30 kg/m² (nonobese). Demographic, surgical, and health-related quality of life data were compared. RESULTS In the nonobese cohort, 947 patients underwent decompression alone and 319 underwent decompression plus fusion. In the obese cohort, 844 patients had decompression alone and 337 had decompression plus fusion. There were no significant differences in the Oswestry Disability Index score or in leg pain improvement at 12 months when comparing decompression with fusion to decompression without fusion in either obese or nonobese cohorts. However, absolute improvement in back pain was less in the obese group when decompression alone had been performed. Blood loss and operative time were lowest in the nonobese D+0 cohort and were higher in obese patients with or without fusion. Obese patients had a longer hospital stay (4.1 days) than the nonobese patients (3.3 days) when fusion had been performed. In-hospital stay was similar in both obese and nonobese D+0 cohorts. No significant differences were seen in 30-day readmission rates among the 4 cohorts. CONCLUSIONS Consistent with the prior literature, equivalent clinical outcomes were found among obese and non-obese patients treated for LSS. In addition, no difference in clinical outcomes as related to the extent of the surgical procedure was observed between obese and nonobese patients. Within the D+0 group, the nonobese patients had slightly better back pain scores at 2 years postoperatively. There may be a higher blood product requirement in obese patients following spine surgery, as well as an extended hospital stay, when fusion is performed. While obesity may influence the decision for or against surgery, the data suggest that obesity should not necessarily alter the appropriate procedure for well-selected surgical candidates.