title: The importance of assessing both inpatient and outpatient surgical quality.
abstract: OBJECTIVE
  We aimed to determine whether hospital-level surgical performance was similar across outpatient and inpatient settings.
  
  
  BACKGROUND
  The majority of surgical procedures in the United States are performed in an outpatient setting but most quality improvement focuses on inpatient care.
  
  
  METHODS
  Using data from the 2006 to 2008 American College of Surgeons- National Surgical Quality Improvement Program, risk-adjusted hospital observed to expected ratios for morbidity and mortality were compared for inpatient and outpatient cases. In addition, hospital outpatient performance in each year was compared with performances in subsequent years.
  
  
  RESULTS
  Hospitals demonstrated variation in outcomes for outpatient morbidity with both good and poor outliers in each year. Outpatient mortality was so rare as to not support robust modeling. There was a lack of congruence between hospital performance for outpatient morbidity and either inpatient morbidity or inpatient mortality in each year, indicating that inpatient performance is not interchangeable with outpatient performance. Outpatient morbidity performance correlation between years was only moderate (correlations 0.449-0.534, all P < 0.001) indicating that although outcomes from 1 year mildly predict subsequent years, substitution of data would likely lead to missed opportunities for improvement.
  
  
  CONCLUSIONS
  Assessments of risk-adjusted hospital-level outpatient morbidity performance demonstrate (1) variability across American College of Surgeons- National Surgical Quality Improvement Program sites; (2) a lack of congruence between outpatient morbidity performance and either inpatient morbidity or mortality performance; (3) year-to-year variation of outpatient morbidity performance at individual institutions. Continuing evaluation of both outpatient and inpatient outcomes is supported. Given the substantial volume of outpatient care delivered, outpatient assessments are likely to be an important component of ongoing quality improvement efforts.
authors.affiliation: Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL, USA. mraval@facs.org
authors.forename: Mehul V
authors.initials: MV
authors.lastname: Raval
authors.forename: Barton H
authors.initials: BH
authors.lastname: Hamilton
authors.forename: Angela M
authors.initials: AM
authors.lastname: Ingraham
authors.forename: Clifford Y
authors.initials: CY
authors.lastname: Ko
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Hall
mesh_terms: D000556:Ambulatory Surgical Procedures / Q000401:mortality / Q000592:standards*; D002423:Cause of Death; D006302:Health Services Research / Q000706:statistics & numerical data; D006801:Humans; D008923:Missouri; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care / Q000706:statistics & numerical data; D010343:Patient Admission / Q000592:standards* / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality; D011785:Quality Assurance, Health Care / Q000592:standards*; D058996:Quality Improvement / Q000592:standards; D019984:Quality Indicators, Health Care / Q000592:standards; D013223:Statistics as Topic; D016019:Survival Analysis