External validation of a predictive model of adverse events following spine surgery.

BACKGROUND CONTEXT: We lack models that reliably predict 30-day postoperative adverse events (AEs) following spine surgery. PURPOSE: We externally validated a previously developed predictive model for common 30-day adverse events (AEs) after spine surgery. STUDY DESIGN/SETTING: This prospective cohort study utilizes inpatient and outpatient data from a tertiary academic medical center. PATIENT SAMPLE: We assessed a prospective cohort of all 276 adult patients undergoing spine surgery in the Department of Neurosurgery at a tertiary academic institution between April 1, 2018 and October 31, 2018. No exclusion criteria were applied. OUTCOME MEASURES: Incidence of observed AEs was compared with predicted incidence of AEs. Fifteen assessed AEs included: pulmonary complications, congestive heart failure, neurological complications, pneumonia, cardiac dysrhythmia, renal failure, myocardial infarction, wound infection, pulmonary embolus, deep venous thrombosis, wound hematoma, other wound complication, urinary tract infection, delirium, and other infection. METHODS: Our group previously developed the Risk Assessment Tool for Adverse Events after Spine Surgery (RAT-Spine), a predictive model of AEs within 30 days following spine surgery using a cohort of approximately one million patients from combined Medicare and MarketScan databases. We applied RAT-Spine to the single academic institution prospective cohort by entering each patient's preoperative medical and demographic characteristics and surgical type. The model generated a patient-specific overall risk score ranging from 0 to 1 representing the probability of occurrence of any AE. The predicted risks are presented as absolute percent risk and divided into low (<17%), medium (17%-28%), and high (>28%). RESULTS: Among the 276 patients followed prospectively, 76 experienced at least one 30-day postoperative AE. Slightly more than half of the cohort were women (53.3%). The median age was slightly lower in the non-AE cohort (63 vs. 66.5 years old). Patients with Medicaid comprised 2.5% of the non-AE cohort and 6.6% of the AE cohort. Spinal fusion was performed in 59.1% of cases, which was comparable across cohorts. There was good agreement between the predicted AE and observed AE rates, Area Under the Curve (AUC) 0.64 (95% CI 0.56-0.710). The incidence of observed AEs in the prospective cohort was 17.8% among the low-risk group, 23.0% in the medium-risk group, and 38.4% in the high risk group (p =.003). CONCLUSIONS: We externally validated a model for postoperative AEs following spine surgery (RAT-Spine). The results are presented as low-, moderate-, and high-risk designations.

The impact of osteoporosis on adult deformity surgery outcomes in Medicare patients.

OBJECTIVE: To identify the impact of osteoporosis (OS) on postoperative outcomes in Medicare patients undergoing ASD surgery. BACKGROUND: Patients with OP and advanced age experience higher than average rates of ASD. However, poor bone density could undermine the durability of a deformity correction. METHODS: We queried the MarketScan Medicare Supplemental database to identify patients Medicare patients who underwent ASD surgery from 2007 to 2016. RESULTS: A total of 2564 patients met the inclusion criteria of this study, of whom n = 971 (61.0%) were diagnosed with osteoporosis. Patients with OP had a similar 90-day postoperative complication rates (OP: 54.6% vs. non-OP: 49.2%, p = 0.0076, not significant after multivariate regression correction). This was primarily driven by posthemorrhagic anemia (37.6% in OP, vs. 33.1% in non-OP). Rates of revision surgery were similar at 90 days (non-OP 15.0%, OP 16.8%), but by 2 years, OP patients had a significantly higher reoperation rate (30.4% vs. 22.9%, p < 0.0001). In multivariate regression analysis, OP increased odds for revision surgery at 1 year (OR 1.4) and 2 years (OR 1.5) following surgery (all p < 0.05). OP was also an independent predictor of readmission at all time points (90 days, OR 1.3, p < 0.005). CONCLUSION: Medicare patients with OP had elevated rates of complications, reoperations, and outpatient costs after undergoing primary ASD surgery.

Anterior Cervical Discectomy and Fusion Versus Laminoplasty for Multilevel Cervical Spondylotic Myelopathy: A National Administrative Database Analysis.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is effective for the treatment of single-level cervical spondylotic myelopathy (CSM). However, the data surrounding multilevel CSM have remained controversial. One alternative is laminoplasty, although evidence comparing these strategies has remained sparse. In the present report, we retrospectively reviewed the readmission and reoperation rates for patients who had undergone ACDF or laminoplasty for multilevel CSM from a national longitudinal administrative claims database. METHODS: We queried the MarketScan Commercial Claims and Encounters database to identify patients who had undergone ACDF or laminoplasty for multilevel CSM from 2007 to 2016. The patients were stratified by operation type. Patients aged <18 years, patients with a history of tumor or trauma, and patients who had undergone anteroposterior approach were excluded from the present study. RESULTS: A total of 5445 patients were included, of whom 1521 had undergone laminoplasty. A matched cohort who had undergone ACDF was identified. The overall 90-day postoperative complication rate was greater in the laminoplasty cohort (odds ratio, 1.48; 95% confidence interval, 1.18-1.86; P < 0.0001). The mean length of stay and 90-day readmission rates were greater in the laminoplasty cohort. The hospital and total payments of the index hospitalization were greater in the ACDF cohort, as were the total payments for ≤2 years after the index hospitalization. CONCLUSIONS: In the present administrative claims database study, no difference was found in the reoperation rate between ACDF and laminoplasty. ACDF resulted in fewer complications and readmissions compared with laminoplasty but was associated with greater costs. Additional prospective research is required to investigate the factors driving the higher costs of ACDF in this population and the long-term clinical outcomes.

Impact of Increasing Age on Outcomes of Spinal Fusion in Adult Idiopathic Scoliosis.

OBJECTIVE: To investigate the role of advancing age on postoperative complications and revision surgery after fusion for scoliosis. METHODS: A retrospective, cohort study was performed using the Thomson Reuters MarketScan database, examining patients with adult scoliosis who underwent spinal fusion from 2000 to 2009. Primary outcomes included infection, hemorrhage and pulmonary embolism (PE) within 90 days of surgery, and refusion. The effect of increasing age was estimated using the odds ratio (OR) of complications in a multivariate logistic regression analysis, and a Cox proportional hazard model estimated the hazard ratio of refusion. RESULTS: A total of 8432 patients were included in this study. Overall, the average age was 53.3 years, with 26.90% males and 39% with a Charlson Comorbidity Score of ≥ 1. Most patients had commercial insurance (66.81%), with 26.03% and 7.16% covered by Medicare and Medicaid, respectively. Increasing age (per 5-year increment) was a significant predictor of hemorrhagic complication (OR, 1.06; confidence interval [CI], 1.01-1.11; P = 0.0196), PE (OR, 1.09; CI, 1.03-1.16; P = 0.0031), infection (OR, 1.04; CI, 1.01-1.07; P = 0.0053), and refusion (hazard ratio, 1.07; CI, 1.02-1.13; P = 0.0103). CONCLUSIONS: In this study, age was associated with increased risk of hemorrhage, PE, infection, and refusion. With the aging population, the role of patient age on postoperative healing and outcomes deserves deeper investigation after repair of adult idiopathic scoliosis.