Geographic and Hospital Variation in Cost of Lumbar Laminectomy and Lumbar Fusion for Degenerative Conditions.
BACKGROUND
Spinal surgery costs vary significantly across hospitals and regions, but there is insufficient understanding of what drives this variation.


OBJECTIVE
To examine the factors underlying the cost variation for lumbar laminectomy/discectomy and lumbar fusions.


METHODS
We obtained patient information (age, gender, race, severity of illness, risk of mortality, population of county of residence, median zipcode income, insurance status, elective vs nonelective admission, length of stay) and hospital data (region, hospital type, bed size, wage index) for all patients who underwent lumbar laminectomy/discectomy (n = 181 267) or lumbar fusions (n = 433 364) for degenerative conditions in the 2001 to 2013 National Inpatient Sample database. We performed unadjusted and adjusted analyses to determine which factors affect cost.


RESULTS
Mean costs for lumbar laminectomy/discectomy and lumbar fusion increased from $8316 and $21 473 in 2001 (in inflation-adjusted 2013 dollars), to $11 405 and $29 438, respectively, in 2013. There was significant regional variation in cost, with the West being the most expensive region across all years and showing the steepest increase in cost over time. After adjusting for patient and hospital factors, the West was 23% more expensive than the Northeast for lumbar laminectomy/discectomy, and 25% more expensive than the Northeast for lumbar fusion ( P < .01). Higher wage index, smaller hospital bed size, and rural/urban nonteaching hospital type were also associated with higher cost for lumbar laminectomy/discectomy and fusion ( P < .01).


CONCLUSIONS
After adjusting for patient factors and wage index, the Western region, hospitals with smaller bed sizes, and rural/urban nonteaching hospitals were associated with higher costs for lumbar laminectomy/discectomy and lumbar fusion.
Department of Neurological Surgery, University of California, San Francisco, California.|Center for Healthcare Value, University of California, San Francisco, California.
Corinna C
CC
Zygourakis
School of Medicine, University of California, San Francisco, California.
Caterina Y
CY
Liu
School of Medicine, University of California, San Francisco, California.
Glenn
G
Wakam
Center for Healthcare Value, University of California, San Francisco, California.|Department of Medicine, University of California, San Francisco, California.
Christopher
C
Moriates
Department of Medicine, University of California, San Francisco, California.
Christy
C
Boscardin
Department of Neurological Surgery, University of California, San Francisco, California.
Christopher P
CP
Ames
Department of Neurological Surgery, University of California, San Francisco, California.
Praveen V
PV
Mummaneni
Department of Neurosurgery, Stanford University Medical Center, Palo Alto, California.
John
J
Ratliff
Center for Healthcare Value, University of California, San Francisco, California.|Department of Medicine, University of California, San Francisco, California.|Philip Lee Institute for Health Policy Studies, University of California, San Francisco, California.
R Adams
RA
Dudley
Center for Healthcare Value, University of California, San Francisco, California.|Department of Medicine, University of California, San Francisco, California.
Ralph
R
Gonzales
D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D007796:Laminectomy / Q000191:economics / Q000706:statistics & numerical data; D008159:Lumbar Vertebrae / Q000601:surgery*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000191:economics / Q000706:statistics & numerical data
Cost of surgery; Cost variation; Geographic variation; Lumbar fusion; Lumbar laminectomy; National inpatient sample (NIS) database