Predictors of Hospital Readmission and Surgical Site Infection in the United States, Denmark, and Japan: Is Risk Stratification a Universal Language?
METHODS
Retrospective review of three spine surgery databases.


OBJECTIVE
The purpose of the present study is to determine whether predictors of hospital readmission and surgical site infection (SSI) after lumbar fusion will be the same in United States, Denmark, and Japan.


BACKGROUND
Because clinical decision making becomes more data driven, risk stratification will be crucial to minimize complications. Spine surgeons worldwide face this issue, leading to parallel efforts to address risk stratification. This raises the question as to whether pooled data would be valuable and whether models generated in one country would be applicable to other populations.


METHODS
Predictors of SSI and 30-day readmission from three prospective databases (National Neurosurgery Quality and Outcomes Database [N2QOD] N = 2653, DaneSpine N = 1993, Japan Multicenter Spine Database [JAMSD] N = 3798) were determined and compared to identify common or divergent predictive risks.


RESULTS
Predictive variables differed in the three databases, for both readmission and SSI. Factors predictive for hospital readmission were American Society of Anesthesiologists (ASA) grade in N2QOD (P = 0.013, odds ratio [OR] 2.08), fusion levels in DaneSpine (P = 0.005, OR 1.67), and sex in JAMSD (P = 0.001, OR = 2.81). Associated differences in demographics and procedural factors included mean ASA grade (N2QOD = 2.45, JAMSD = 1.72) and fusion levels (N2QOD = 1.39, DaneSpine = 1.52, JAMSD = 1.34). For SSI, sex (P = 0.000, OR = 3.30), diabetes (P = 0.000, OR = 2.90), and length of stay (P = 0.000, OR = 1.02) were predictive in JAMSD. No predictors were identified in N2QOD or DaneSpine.


CONCLUSIONS
Predictors of SSI and hospital readmission differ in the United States, Denmark, and Japan, suggesting that risk stratification models may need to be population specific or adjusted. Some differences in measured parameters exist in the three databases analyzed; however, patient and procedure selection also appear to differ and may limit the ability to directly pool data from different regions. Therefore, risk stratification models developed in one country may not be directly applicable to other countries.


METHODS
2.
Norton Leatherman Spine Center, Louisville, KY.
Steven
S
Glassman
Norton Leatherman Spine Center, Louisville, KY.
Leah Y
LY
Carreon
Rygkirurgisk Center Middelfart, Sygehus Lillebælt, Middelfart, Denmark.
Mikkel
M
Andersen
Carolina Neurosurgery and Spine, Charlotte, NC.
Anthony
A
Asher
Department of Orthopedic Surgery, Aalborg University Hospital, Aalborg, Denmark.
Soren
S
Eiskjær
Spine Unit, Department of Orthopaedic Surgery, University Hospital of Copenhagen, København, Denmark.
Martin
M
Gehrchen
Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Shiro
S
Imagama
Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan.
Ken
K
Ishii
Department of Orthopedic Surgery, Faculty of Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan.
Takahashi
T
Kaito
Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan.
Yukihiro
Y
Matsuyama
Department of Orthopaedic Surgery, Dokkyo Medical University School of Medicine, Tochigi, Japan.
Hiroshi
H
Moridaira
Department of Neurological Surgery, University of California-San Francisco, San Francisco, CA.
Praveen
P
Mummaneni
Department of Neurosurgery, University of Virginia, Charlottesville, VA.
Christopher
C
Shaffrey
Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan.
Morio
M
Matsumoto
D003718:Denmark / Q000453:epidemiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology