Resident Physician Brown University Providence, Rhode Island, United States
Introduction: Use of lumbar fusion has increased significantly over the last 2 decades. For patients with lumbar stenosis and spondylolisthesis (LSS), 2 landmark prospective trials published in NEJM in 2016 failed to find clear evidence in favor of laminectomy with fusion (LF) over laminectomy alone (LA) in this population. We hypothesized that these results may have reduced national utilization of fusion for this indication since 2016 and sought to interrogate practice patterns over this time period.
Methods: We conducted a retrospective cohort analysis of admitted patients undergoing LA or LF for LSS in the National Inpatient Sample (NIS) from 2016-2019. Standard NIS weighting and survey methods were used.
Results: Among included patients, 34,465 (18%) underwent LA, with a significant decline from 2016 (34%) to 2019 (9%). In univariable analysis, LA patients differed significantly from LF patients with regard to age, race, insurance status, admission type, All Patients Refined Diagnosis Related Groups (ARP-DRG) Severity of Illness, APR-DRG Risk of Mortality, Region of the Country, Hospital Size, and Median Income per ZIP Code (all p ≤ 0.002). In multivariable logistic regression, age (aOR 0.96, 95% CI: 0.95-0.97), Medicaid insurance (aOR 0.79, 95% CI: 0.68-0.93), self-pay status (aOR 0.66, 95% CI: 0.45-0.95), moderate severity of illness (aOR 0.92, 95% CI: 0.87-0.99), and medium (aOR 0.70, 95% CI: 0.62-0.80) and large (aOR 0.67, 95% CI: 0.60-0.75) hospital size were associated with decreased odds of LF. Conversely, elective admission status (aOR 2.28, 95% CI: 2.02-2.59), Midwest region (aOR 1.33, 95% CI: 1.17-1.52), and Southern region (aOR 1.29, 95% CI: 1.14-1.45) were associated with increased odds of LF. While LF was paradoxically associated with shorter length of stay (3.16 vs 3.29 days, p < 0.001), total admission costs were higher ($31,570 vs $18,778, p < 0.001).
Conclusion : Despite evidence to the contrary, relative utilization of laminectomy with fusion relative to laminectomy without fusion has continued to increase since 2016. A variety of patient- and hospital-level factors are strongly associated with procedure choice. These trends may reflect perceived ambiguity of trial results, unchanged surgical reimbursement schemes for LSS, or a drastic nationwide shift toward outpatient and/or observation-status LA.
