Increased Surgeon-specific Experience and Volume is Correlated With Improved Clinical Outcomes in Lumbar Fusion Patients

STUDY DESIGN

The present study design was that of a single center, retrospective cohort study to evaluate the influence of surgeon-specific factors on patient functional outcomes at 6 months following lumbar fusion. Retrospective review of a prospectively maintained database of patients who underwent neurosurgical lumbar instrumented arthrodesis identified the present study population.

OBJECTIVE

This study seeks to evaluate surgeon-specific variable effects on patient-reported outcomes such as Oswestry Disability Index (ODI) and the effect of North American Spine Society (NASS) concordance on outcomes in the setting of variable surgeon characteristics.

SUMMARY OF BACKGROUND DATA

Lumbar fusion is one of the fastest growing procedures performed in the United States. Although the impact of surgeon-specific factors on patient-reported outcomes has been contested, studies examining these effects are limited.

METHODS

This is a single center, retrospective cohort study analyzing a prospectively maintained database of patients who underwent neurosurgical lumbar instrumented arthrodesis by 1 of 5 neurosurgery fellowship trained spine surgeons. The primary outcome was improvement of ODI at 6 months postoperative follow-up compared with preoperative ODI.

RESULTS

A total of 307 patients were identified for analysis. Overall, 62% of the study population achieved minimum clinically important difference (MCID) in ODI score at 6 months. Years in practice and volume of lumbar fusions were statistically significant independent predictors of MCID ODI on multivariable logistic regression ( P =0.0340 and P =0.0343, respectively). Concordance with evidence-based criteria conferred a 3.16 (95% CI: 1.03, 9.65) times greater odds of achieving MCID.

CONCLUSION

This study demonstrates that traditional surgeon-specific variables predicting surgical morbidity such as experience and procedural volume are also predictors of achieving MCID 6 months postoperatively from lumbar fusion. Independent of surgeon factors, however, adhering to evidence-based guidelines can lead to improved outcomes.

Burden of preoperative opioid use and its impact on healthcare utilization after primary single level lumbar discectomy

BACKGROUND CONTEXT

The complication profile and higher cost of care associated with preoperative opioid use and spinal fusion is well described. However, the burden of opioid use and its impact in patients undergoing lumbar discectomy is not known. Knowledge of this, especially for a relatively benign and predictable procedure will be important in bundled and value-based payment models.

PURPOSE

To study the burden of pre-operative opioid use and its effect on postoperative healthcare utilization, cost, and opioid use in patients undergoing primary single level lumbar discectomy.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

A 29,745 patients undergoing primary single level lumbar discectomy from the IBM MarketScan (2000-2018) database.

OUTCOME MEASURES

Ninety-day and 1-year utilization of lumbar epidural steroid injections, emergency department (ED) services, lumbar magnetic resonance imaging, hospital readmission, and revision lumbar surgery. Continued opioid use beyond 3-months postoperatively until 1-year was also studied. We have reported costs associated with healthcare utilization among opioid groups.

METHODS

Patients were categorized in opioid use groups based on the duration and number of oral prescriptions before discectomy (opioid naïve, < 3-months opioid use, chronic preoperative use, chronic preoperative opioid use with 3-month gap before surgery, and other). The risk of association of preoperative opioid use with outcome measures was studied using multivariable logistic regression analysis with adjustment for various demographic and clinical variables.

RESULTS

A total of 29,745 patients with mean age of 45.3±9.6 years were studied. Pre-operatively, 29.0% were opioid naïve, 35.0% had < 3-months use and 12.0% were chronic opioid users. There was a significantly higher rate of post-operative lumbar epidural steroid injections, magnetic resonance imaging , ED visits, readmission and revision surgery within 90-days and 1-year after surgery in chronic pre-operative opioid users as compared with patients with < 3-months use and opioid naïve patients (p<.001). Chronic post-operative opioid use was present in 62.6% of the preoperative chronic opioid users as compared with 5.6% of patients with < 3-months opioid use. A 3-month prescription free period before surgery in chronic pre-operative opioid users cut the incidence of chronic post-operative opioid use by more than half, at 25.7%. Cost of care and adjusted analysis of risk have been described.

CONCLUSION

Chronic preoperative opioid use was present in 12% of a national cohort of lumbar discectomy patients. Such opioid use was associated with significantly higher post-operative healthcare utilization, risk of revision surgery, and costs at 90-days and 1-year postoperatively. Two-third of chronic preoperative opioid users had continued long-term postoperative opioid use. However, a 3-month prescription free period before surgery in chronic opioid users reduces the risk of long-term postoperative use. This data will be useful for patient education, pre-operative opioid use optimization, and risk-adjustment in value-based payment models.

Obesity in Patients Undergoing Lumbar Degenerative Surgery-A Retrospective Cohort Study of Postoperative Outcomes

STUDY DESIGN

Retrospective cohort studying using a national, administrative database.

OBJECTIVE

The aim of this study was to determine the postoperative complications and quality outcomes of patients with and without obesity undergoing surgical management for lumbar degenerative disease (LDD).

SUMMARY OF BACKGROUND DATA

Obesity is a global epidemic that negatively impacts health outcomes. Characterizing the effect of obesity on LDD surgery is important given the growing elderly obese population.

METHODS

This study identified patients with who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether the patient had a concurrent diagnosis of obesity at time of surgery. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between patients with and without obesity. Patients who underwent three or more levels surgical correction, were under the age of 18 years, or those with any previous history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.

RESULTS

A total of 67,215 patients underwent primary lumbar degenerative surgery, of which 22,405 (33%) were obese. After propensity score matching, baseline covariates of the two cohorts were similar. The complication rate was 8.3% in the nonobese cohort and 10.4% in the obese cohort (P < 0.0001). Patients with obesity also had longer lengths of stay (2.7 days vs. 2.4 days, P < 0.05), and higher rates of reoperation and readmission at all time-points through the study follow-up period to their nonobese counterparts (P < 0.05). Including payments after discharge, lumbar degenerative surgery in patients with obesity was associated with higher payments throughout the 2-year follow-up period ($68,061 vs. $59,068 P < 0.05).

CONCLUSION

Patients with a diagnosis of obesity at time of LDD surgery are at a higher risk for postoperative complications, reoperation, and readmission.Level of Evidence: 4.

Cost analysis of primary single-level lumbar discectomies using the Value Driven Outcomes database in a large academic center

BACKGROUND CONTEXT

Improving value is an established point of emphasis to reduce the rapidly rising health care costs in the United States. Back pain is a major driver of costs with a substantial fraction caused by lumbar radiculopathy. The most common surgical treatment for lumbar radiculopathy is microdiscectomy. Research is sparse regarding variables driving cost in microdiscectomies and often limited by cost data derived from payer-based Medicare data.

PURPOSE

To identify targets for cost reduction by determining variables associated with significant cost variation in microdiscectomies, using cost data derived from the Value Driven Outcomes tool and actual system costs.

STUDY DESIGN

Single-center, retrospective study of prospectively collected registry data.

PATIENT SAMPLE

Six hundred twenty-two patients identified by CPT code and manually screened for initial, unilateral, single-level lumbar discectomy performed between 2014 and 2018 at a single institution.

OUTCOME MEASURES

Primary outcome measures include total direct cost, clinical length of stay, and OR minutes. Total Direct Cost was further differentiated into facility and nonfacility costs.

METHODS

Univariate and multivariate generalized linear models (GLM) were used to identify variables associated with variation in primary outcome measures. Costs were normalized by mean cost for patients with normal body mass index (BMI) and a healthy American Society of Anesthesiologists (ASA) classification. Average marginal effects were reported as percentage of normalized costs.

RESULTS

Advanced age, male gender, Hispanic, black, unemployment, obesity, higher ASA class, insurance status, and being retired were positively associated with costs in univariate analysis. Asian, Native American, outpatient procedures, and being a student were associated with decreases in costs. In multivariate analysis, we found that obesity led to higher average marginal total direct (9%), total facility (15%), and facility OR costs (22%), as well as 24 more OR minutes per surgery. While being overweight was not associated with greater total direct costs, it was associated with higher total facility (8%), and facility OR costs (12%), with 11 more OR minutes per surgery. Age was associated with a longer LOS but not with OR costs. As expected, outpatient surgical costs, LOS, and OR time were significantly lower than inpatient procedures. Severe systematic disease was associated with greater total and nonfacility costs. In addition, Medicare patients had higher facility costs (14%) compared to privately insured patients.

CONCLUSIONS

Significant drivers of total direct cost in multivariate GLM analysis were obesity, severe systemic disease and inpatient surgery. Average LOS was increased due to age and inpatient status, conversely it was decreased by unemployment and retirement. Significant variables in OR time were male sex, Hispanic race and both obese and overweight BMIs.

Recoup From Home? Comparison of Relative Cost Savings for ACDF, Lumbar Discectomy, and Short Segment Fusion Performed in the Inpatient Versus Outpatient Setting

STUDY DESIGN

Broad narrative review.

OBJECTIVE

To review and summarize the current literature on the cost efficacy of performing ACDF, lumbar discectomy and short segment fusions of the lumbar spine performed in the outpatient setting.

METHODS

A thorough review of peer- reviewed literature was performed on the relative cost-savings, as well as guidelines, outcomes, and indications for successfully implementing outpatient protocols for routine spine procedures.

RESULTS

Primary elective 1-2 level ACDF can be safely performed in most patient populations with a higher patient satisfaction rate and no significant difference in 90-day reoperations and readmission rates, and a savings of 4000 to 41 305 USD per case. Lumbar discectomy performed through minimally invasive techniques has decreased recovery times with similar patient outcomes to open procedures. Performing lumbar microdiscectomy in the outpatient setting is safe, cheaper by as much as 12 934 USD per case and has better or equivalent outcomes to their inpatient counterparts. Unlike ACDF and lumbar microdiscectomy, short segment fusions are rarely performed in ASCs. However, with the advent of minimally invasive techniques paired with improved pain control, same-day discharge after lumbar fusion has limited clinical data but appears to have potential cost-savings up to 65-70% by reducing admissions.

CONCLUSION

Performing ACDF, lumbar discectomy and short segment fusions in the outpatient setting is a safe and effective way of reducing cost in select patient populations.

Bundled Payment Models in Spine Surgery

STUDY DESIGN

The following is a narrative discussion of bundled payments in spine surgery.

OBJECTIVE

The cost of healthcare in the United States has continued to increase. To lower the cost of healthcare, reimbursement models are being investigated as potential cost saving interventions by driving incentives and quality improvement in fields such a spine surgery.

METHODS

Narrative overview of literature pertaining to bundled payments in spine surgery synthesizing findings from computerized databases and authoritative texts.

RESULTS

Spine surgery is challenging to define payment modes because of high cost variability and surgical decision-making nuances. While implementing bundled care payments in spine surgery, it is important to understand concepts such as value-based purchasing, episodes of care, prospective versus retrospective payment models, one versus two-sided risk, risk adjustment, and outlier protection. Strategies for implementation underscore the importance of risk stratification and modeling, adoption of evidence based clinical pathways, and data collection and dissemination. While bundled care models have been successfully implemented, challenges facing institutions adopting bundled care payment models include financial stressors during adoption of the model, distribution of risks, incentivization of treating only low risk patients, and nuanced variation in procedures leading to variation in costs.

CONCLUSION

An alternative for fee for service payments, bundled care payments may lead to higher cost savings and surgeon accountability in a patient's care.

Cost of Readmissions Following Anterior Cervical Discectomy and Fusion: Insights from the Nationwide Readmissions Database

BACKGROUND

Postoperative readmissions are a significant driver of variation in bundled care costs associated with cervical spine surgery.

OBJECTIVE

To determine the factors predicting the cost of readmission episodes following elective anterior cervical discectomy and fusion (ACDF).

METHODS

We queried the Healthcare Cost and Utilization Project Nationwide Readmissions Database for patients undergoing elective ACDF during 2012 to 2015. Multivariable linear regression was performed to establish the factors associated with the cost of each 30-/90-d readmission episode.

RESULTS

A total of 139 877 and 113 418 patients met inclusion criteria for the evaluation of 30- and 90-d readmissions, respectively. Among these, the national rates of 30- and 90-d readmission after an elective ACDF were 3% and 6%, respectively. The median cost of a 30- and 90-d readmission episode was $6727 (IQR: $3844-$13 529) and $8507 (IQR: $4567-$17 460), respectively. Relative predictor importance analysis revealed that the number of procedures at index admission (IA), length of stay at IA, and time elapsed between index surgical admission and readmission were the top predictors of both 30- and 90-d readmission costs (all P < .001). Although cervical myelopathy accounted for only 3.6% of all 30-d readmissions, it accounted for the largest share (8%) of 30-d readmission costs.

CONCLUSION

In this analysis from a national all-payer database, we determined the factors associated with the cost of readmissions following elective ACDF. These results are important in assisting policymakers and payers with a better risk adjustment in bundled care payment systems and for surgeons in implementing readmission cost-reduction efforts.

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.

Utility of the Hospital Frailty Risk Score for Predicting Adverse Outcomes in Degenerative Spine Surgery Cohorts

BACKGROUND

As spine surgery becomes increasingly common in the elderly, frailty has been used to risk stratify these patients. The Hospital Frailty Risk Score (HFRS) is a novel method of assessing frailty using International Classification of Diseases, Tenth Revision (ICD-10) codes. However, HFRS utility has not been evaluated in spinal surgery.

OBJECTIVE

To assess the accuracy of HFRS in predicting adverse outcomes of surgical spine patients.

METHODS

Patients undergoing elective spine surgery at a single institution from 2008 to 2016 were reviewed, and those undergoing surgery for tumors, traumas, and infections were excluded. The HFRS was calculated for each patient, and rates of adverse events were calculated for low, medium, and high frailty cohorts. Predictive ability of the HFRS in a model containing other relevant variables for various outcomes was also calculated.

RESULTS

Intensive care unit (ICU) stays were more prevalent in high HFRS patients (66%) than medium (31%) or low (7%) HFRS patients. Similar results were found for nonhome discharges and 30-d readmission rates. Logistic regressions showed HFRS improved the accuracy of predicting ICU stays (area under the curve [AUC] = 0.87), nonhome discharges (AUC = 0.84), and total complications (AUC = 0.84). HFRS was less effective at improving predictions of 30-d readmission rates (AUC = 0.65) and emergency department visits (AUC = 0.60).

CONCLUSION

HFRS is a better predictor of length of stay (LOS), ICU stays, and nonhome discharges than readmission and may improve on modified frailty index in predicting LOS. Since ICU stays and nonhome discharges are the main drivers of cost variability in spine surgery, HFRS may be a valuable tool for cost prediction in this specialty.

How does preoperative opioid use impact postoperative health-related quality of life scores for patients undergoing lumbar microdiscectomy?

BACKGROUND CONTEXT

Narcotic use amongst patients suffering from lumbar radiculopathy is common, but the clinical benefit of narcotics for lumbar radiculopathy is likely minimal. It is unknown what the impact of preoperative use of narcotics has on outcomes related to lumbar microdiscectomy.

PURPOSE

Determine the impact that preoperative opioid use has on postoperative outcomes after lumbar microdisectomy.

STUDY DESIGN

Retrospective analysis of a prospectively collected database.

PATIENT SAMPLE

One hundred and twenty-six patients undergoing a microdiscectomy for a lumbar disc herniation.

OUTCOME MEASURES

Patient-reported outcomes measurement information system mental health scores (PROMIS MHS), patient-reported outcomes measurement information system physical health scores (PROMIS PHS) and oswestry disability index (ODI).

METHODS

We analyzed a prospectively collected database of patients undergoing a lumbar microdiscectomy for preoperative opioid use. We measured the severity of lumbar pathology on MRI based on degree of facet/disc degeneration and cross-sectional area of the dural tube at the disc herniation. We tracked PROMIS MHS, PROMIS PHS and ODI for patients both preoperatively and postoperatively. A Mann-Whitney test was used to compare HRQOL scores and time to MCID for the opioid using cohort (OC) and the nonopioid using cohort (non-OC). We performed a linear regression analysis to determine correlation between preoperative opioid use and postoperative HRQOLs.

RESULTS

There were 44 of 126 microdiscectomy patients in the OC (32.5%). There was no difference in the dural cross-sectional area (p=.91), degree of facet degeneration (p=.38), or disc degeneration (p=.5) between OC and non-OC. There were no differences in PROMIS PHS, PROMIS MHS or ODI between the OC and non-OC at the preoperative visit and all postoperative time points. There were no differences in time to reach MCID between the OC and non-OC for ODI (p=.9), PROMIS PHS (p=.64) or PROMIS MHS (p=.90). At three months out from surgery there was a statistically significant correlation between pre-op opioid use and ODI (p=.02), PROMIS MHS (p=.02) and PROMIS PHS (p=.049).

CONCLUSIONS

Our results demonstrate that patients that use opioids prior to lumbar microdiscectomy have equivalent postoperative outcomes as those that do not use opioids. Use of higher doses of opioids is associated with worse short-term outcomes.