title: Morphometric age and surgical risk.
abstract: BACKGROUND
  A cornerstone of a surgeon's clinical assessment of suitability for major surgery is best described as the "eyeball test." Preoperative imaging may provide objective measures of this subjective assessment by calculating a patient's morphometric age. Our hypothesis is that morphometric age is a surgical risk factor distinct from chronologic age and comorbidity and correlates with surgical mortality and length of stay.
  
  
  METHODS
  This is a retrospective cohort study within a large academic medical center. Using novel analytic morphomic techniques on preoperative CT scans, a morphometric age was assigned to a random sample of patients having inpatient general and vascular abdominal surgery from 2006 to 2011. The primary outcomes for this study were postoperative mortality (1-year) and length of stay (LOS).
  
  
  RESULTS
  The study cohort (n = 1,370) was stratified into tertiles based on morphometric age. The postoperative risk of mortality was significantly higher in the morphometric old age group when compared with the morphometric middle age group (odds ratio 2.42, 95% CI 1.52 to 3.84, p < 0.001). Morphometric old age patients were predicted to have a LOS 4.6 days longer than the morphometric middle age tertile. Similar trends were appreciated when comparing morphometric middle and young age tertiles. Chronologic age correlated poorly with these outcomes. Furthermore, patients in the chronologic middle age tertile found to be of morphometric old age had significantly inferior outcomes (mortality 21.4% and mean LOS 13.8 days) compared with patients in the chronologic middle age tertile found to be of morphometric young age (mortality 4.5% and mean LOS 6.3 days, p < 0.001 for both).
  
  
  CONCLUSIONS
  Preoperative imaging can be used to assign a morphometric age to patients, which accurately predicts mortality and length of stay.
authors.affiliation: Morphomics Analysis Group (MAG), Department of Surgery, University of Michigan, Ann Arbor, MI 48109-5331, USA. englesbe@med.umich.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Englesbe
authors.forename: Michael N
authors.initials: MN
authors.lastname: Terjimanian
authors.forename: Jay S
authors.initials: JS
authors.lastname: Lee
authors.forename: Kyle H
authors.initials: KH
authors.lastname: Sheetz
authors.forename: Calista M
authors.initials: CM
authors.lastname: Harbaugh
authors.forename: Adnan
authors.initials: A
authors.lastname: Hussain
authors.forename: Sven A
authors.initials: SA
authors.lastname: Holcombe
authors.forename: June
authors.initials: J
authors.lastname: Sullivan
authors.forename: Darrell A
authors.initials: DA
authors.lastname: Campbell
authors.forename: Stewart C
authors.initials: SC
authors.lastname: Wang
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Sonnenday
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D019540:Area Under Curve; D015897:Comorbidity; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013514:Surgical Procedures, Operative / Q000401:mortality*; D014057:Tomography, X-Ray Computed; D014656:Vascular Surgical Procedures / Q000401:mortality