title: Impact of a critical pathway on the results of carotid endarterectomy in a tertiary care university hospital: effect of methods on outcome.
abstract: OBJECTIVE
  A carotid endarterectomy critical pathway (CP) targeting a 3-day postoperative course was introduced in March 1994. This retrospective analysis assesses its impact on operative results, postoperative length of stay (POD), and cost of hospitalization (COH).
  
  
  METHODS
  One hundred eighty-six patients who underwent 201 carotid endarterectomy procedures from Nov. 1992 to Feb. 1994 (Pre-CP; n = 67) and from Apr. 1994 to Jul. 1995 (Post-CP; n = 134) at Johns Hopkins Hospital, a tertiary care referral center, were evaluated.
  
  
  RESULTS
  The Pre-CP and Post-CP groups had similar risk factors, postoperative morbidity rates, and mortality rates. Furthermore, they had similar mean POD (Pre-CP, 6.0 +/- 0.5 days; Post-CP, 5.7 +/- 0.6 days; p = 0.79) and COH. However, only 85 of the Post-CP (63%) patients were actually placed on the CP (CP-starters); the mean POD was 3.4 +/- 0.3 days among these CP-starters (p < 0.0001) and 2.8 +/- 0.1 days among the 74 Post-CP patients (55%) that remained on the pathway (CP-finishers; p < 0.0001). The mean COH was reduced from $12,881 (Pre-CP) to $9701 for the CP-starters (p = 0.01) and to $8572 for the CP-finishers (p = 0.0001). However, we found that only 47 of the Pre-CP patients (70%) would have been eligible for the CP, and the mean POD among those cases was 4.2 +/- 0.4 days, which was not different than the mean POD among the CP-starters (p = 0.17). The mean COH of the eligible Pre-CP cases, $9508, was not significantly different from the COH of the CP-starters (p = 0.97).
  
  
  CONCLUSIONS
  This subset analysis emphasizes the importance of establishing an accurate "control" group when studying a CP, because using all of the Pre-CP cases as the "control" group in the original analysis, including patients who would not have been candidates for the CP, clearly overstated the beneficial impact of the CP.
authors.affiliation: Department of Surgery, Johns Hopkins Hospital, Baltimore, MD 21287-4685, USA.
authors.forename: A
authors.initials: A
authors.lastname: Dardik
authors.forename: G M
authors.initials: GM
authors.lastname: Williams
authors.forename: S L
authors.initials: SL
authors.lastname: Minken
authors.forename: B A
authors.initials: BA
authors.lastname: Perler
mesh_terms: D000704:Analysis of Variance; D000792:Angiography; D015142:Baltimore; D019091:Critical Pathways; D003627:Data Interpretation, Statistical; D016894:Endarterectomy, Carotid / Q000009:adverse effects / Q000191:economics / Q000401:mortality; D017721:Hospital Costs; D006785:Hospitals, University / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome