Understanding the Impact of Obesity on Short-term Outcomes and In-hospital Costs After Instrumented Spinal Fusion.
BACKGROUND
Obesity rates continue to rise along with the number of obese patients undergoing elective spinal fusion.


OBJECTIVE
To evaluate the impact of obesity on resource utilization and early complications in patients undergoing surgery for degenerative spine disease.


METHODS
A single-institution retrospective analysis was conducted on patients with degenerative spine disease requiring instrumentation between 2008 and 2012. The 801 identified patients were grouped based on a body mass index (BMI) of <30 (nonobese, n = 478), ≥30 and <40 (obese, n = 283), and alternatively BMIs of ≥40 (morbidly obese, n = 40). Baseline characteristics, surgical outcomes and requirements, complications, and cost were compared. Logistic and linear regression analyses were used to determine the strength of association between obesity and outcomes for categorical and continuous data, respectively.


RESULTS
Significant differences were found in comorbidities between cohorts. Multivariate analysis revealed significant associations between obesity and longer anesthesia times (30 minutes, P = .008), and surgical times (24 minutes, P = .02). Additionally, there was a 2.8 times higher rate of wound complications in obese patients (4.2% vs 1.5, P = .03), and 2.5 times higher rate of major medical complications (7.8% vs 3.1, P = .01). Morbid obesity resulted in a 10 times higher rate of wound complications (P < .001). Morbid obesity resulted in a $9078 (P = .005) increase in overall cost of care.


CONCLUSIONS
Increased BMI is associated with longer operative times, increased complication rates, and increased cost independent of comorbidities. These effects are more pronounced with morbidly obese patients, further supporting a role for preoperative weight loss.
*Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota;‡Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida;§Department of Anesthesia, Mayo Clinic, Rochester, Minnesota.
Dominique M
DM
Higgins
Grant W
GW
Mallory
Ryan F
RF
Planchard
Ross C
RC
Puffer
Mohamed
M
Ali
Marcus J
MJ
Gates
William E
WE
Clifton
Jeffrey T
JT
Jacob
Timothy B
TB
Curry
Daryl J
DJ
Kor
Jeremy L
JL
Fogelson
William E
WE
Krauss
Michelle J
MJ
Clarke
D015992:Body Mass Index; D015331:Cohort Studies; D015897:Comorbidity; D032882:Comprehension; D005260:Female; D006295:Health Resources / Q000191:economics / Q000706:statistics & numerical data; D017721:Hospital Costs / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000191:economics* / Q000453:epidemiology / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis / Q000191:economics* / Q000453:epidemiology; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000191:economics* / Q000295:instrumentation* / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome