Is academic department teaching status associated with adverse outcomes after lumbar laminectomy and discectomy for degenerative spine diseases?

BACKGROUND CONTEXT

Lumbar laminectomy and discectomy surgeries are among the most common procedures performed in the United States, and often take place at academic teaching hospitals, involving the care of resident physicians. While academic institutions are critical for the maturation of the next generation of attending surgeons, concerns have been raised regarding the quality of resident-involved care. There is conflicting evidence regarding the effects of resident participation in teaching hospitals on spine surgery patient outcomes. As the volume of lumbar laminectomy and discectomy increases, it is imperative to determine how academic status impacts clinical and economic outcomes.

PURPOSE

The purpose of this study is to determine if lumbar laminectomy and discectomy surgeries for degenerative spine diseases performed at academic teaching centers is associated with more adverse clinical outcomes and increased cost compared to those performed at nonacademic centers.

STUDY DESIGN/SETTING: This study is a multi-center retrospective cohort study using a New York Statewide database.

PATIENT SAMPLE

We identified 36,866 patients who met the criteria through the New York Statewide Planning and Research Cooperative System who underwent an elective lumbar laminectomy and/or discectomy in New York State between January 1, 2009 and September 30, 2014.

OUTCOME MEASURES

The primary functional outcomes of interest included: length of stay, cost of the index admission; 30-day and 90-day readmission; 30-day, 90-day, and 1-year return to the operating room.

METHODS

International Classification of Diseases, Ninth revision codes were utilized to define patients undergoing a laminectomy and/or discectomy who also had a diagnosis code for a lumbar spine degenerative condition. We excluded patients with a procedural code for lumbar fusion, as well as those with a diagnosis of scoliosis, neoplasm, inflammatory disorder, infection or trauma. Hospital academic status was determined by the Accreditation Council for Graduate Medical Education. Unique encrypted patient identifiers allowed for longitudinal follow-up for readmission and re-operation analyses. We extracted charges billed for each admission and calculated costs through cost-to-charge ratios. Logistic regression models compared teaching and nonteaching hospitals after adjusting for patient demographics and comorbidities.

RESULTS

Compared to patients at nonteaching hospitals, patients at teaching hospitals were more likely to be younger, male, non-Caucasian, be privately insured and have fewer comorbidities (p<.001). Patients undergoing surgery at teaching hospitals had 10% shorter lengths of stay (2.7 vs. 3.0 days, p<.001), but 21.5% higher costs of admission ($13,693 vs. $11,601 p<.001). Academic institutions had a decreased risk of return to the operating room for revision procedures or irrigation and debridement at 30 days (OR:0.70, 95% confidence interval [CI]: 0.60-0.82, p<.001), 90 days (OR:0.75, 95%CI: 0.66-0.86, p<.001), and 1 year (OR:0.84, 95%CI: 0.77-0.91, p<.001) post index procedure. There was no difference in 30- and 90-day all-cause readmission, or discharge disposition between the two groups.

CONCLUSIONS

Elective lumbar laminectomy and discectomy for degenerative lumbar conditions at teaching hospitals is associated with higher costs, but decreased length of stay and no difference in readmission rates at 30- and 90-days postoperatively compared to nonteaching hospitals. Teaching hospitals had a decreased risk of return to the operating room at 30 days, 90 days and 1 year postoperatively. Our findings might serve as an impetus for other states or regions to compare outcomes at teaching and nonteaching sites.