title: Outcomes reported by the Vascular Quality Initiative and the National Surgical Quality Improvement Program are not comparable.
abstract: OBJECTIVE
  The Vascular Quality Initiative (VQI) and National Surgical Quality Improvement Program (NSQIP) have emerged as the primary vascular surgery quality measurement tools with the purpose of evaluating perioperative outcomes and assessing hospital and physician quality. VQI uses self-reporting to capture all index vascular procedures during the inpatient period. NSQIP employs nurse abstractors to capture a sample of procedures and covers 30-day events. We hypothesize that patients undergoing lower extremity bypass (LEB) will exhibit high concordance for preoperative variables and low concordance for postoperative variables between these data sets.
  
  
  METHODS
  All patients undergoing LEB for peripheral arterial disease at the University of Massachusetts captured in both VQI and NSQIP databases were reviewed (2007-2012). Concordance between categorical variables was assessed by κ correlation coefficient. All postoperative variables were compared during equivalent inpatient stay. Events between discharge and 30 days postoperatively were tabulated with use of the NSQIP data set.
  
  
  RESULTS
  We identified 240 patients undergoing LEB captured in both VQI and NSQIP. Comparison of this identical patient cohort between VQI and NSQIP revealed a moderate to strong agreement for most preoperative variables except for congestive heart failure (κ = 0.14) and hypertension (κ = 0.35), which showed poor agreement. Concordance for inpatient postoperative variables was high for mortality (κ = 1.0) and myocardial infarction (κ = 0.86) but moderate for pulmonary complications (κ = 0.57) and poor for unplanned return to the operating room (κ = 0.41), wound infection (κ = -0.01), and change in renal function (κ = -0.01). A majority of postoperative events (71%) occurred between discharge and 30 days postoperatively, with a significantly higher incidence of wound infections in the outpatient setting (4.2% vs 95.8%; P < .0001).
  
  
  CONCLUSIONS
  VQI and NSQIP demonstrate substantial concordance for most preoperative variables and poor concordance for most postoperative variables, even at identical collection periods. This discordance is a result of differences in data collection methods and variable definitions. On the basis of these findings, VQI and NSQIP data sets cannot be used to directly compare risk-adjusted patient outcomes between institutions.
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass. Electronic address: francesco.aiello@umassmemorial.org.
authors.forename: Francesco A
authors.initials: FA
authors.lastname: Aiello
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Bing
authors.initials: B
authors.lastname: Shue
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Nisha
authors.initials: N
authors.lastname: Kini
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Amy
authors.initials: A
authors.lastname: Rosen
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Louis
authors.initials: L
authors.lastname: Messina
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass.
authors.forename: William
authors.initials: W
authors.lastname: Robinson
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Philimon
authors.initials: P
authors.lastname: Gona
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Andres
authors.initials: A
authors.lastname: Schanzer
mesh_terms: D016208:Databases, Factual; D005260:Female; D006333:Heart Failure / Q000150:complications; D006801:Humans; D006973:Hypertension / Q000150:complications; D007668:Kidney / Q000503:physiopathology; D035002:Lower Extremity / Q000098:blood supply / Q000601:surgery; D008297:Male; D008485:Medical Audit; D009203:Myocardial Infarction / Q000453:epidemiology; D017063:Outcome Assessment, Health Care / Q000379:methods*; D058729:Peripheral Arterial Disease / Q000150:complications / Q000601:surgery*; D011014:Pneumonia / Q000453:epidemiology; D011184:Postoperative Period; D057234:Preoperative Period; D019984:Quality Indicators, Health Care; D012086:Reoperation; D012189:Retrospective Studies; D057566:Self Report; D013530:Surgical Wound Infection / Q000453:epidemiology; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality / Q000592:standards*