PURPOSE: Despite their popularity, critical pathways have been evaluated in only a few controlled studies. We evaluated the effectiveness of critical pathways in reducing length of hospital stay.

SUBJECTS AND METHODS: We compared postoperative lengths of stay of patients who underwent coronary artery bypass graft (CABG) surgery, total knee replacement, colectomy, thoracic surgery, or hysterectomy before and after pathway implementation at a university hospital. For three procedures, changes in lengths of stay at neighboring hospitals without pathway programs were assessed for comparison.

RESULTS: A total of 6,796 patients underwent one of the procedures during the study. The percentage of eligible patients managed on a critical pathway ranged from 94% for hysterectomy to 26% for colectomy. For most procedures, the postoperative length of stay was decreasing during the baseline period. After pathway implementation, the length of stay decreased 21% for total knee replacement, 9% for CABG surgery, 7% for thoracic surgery, 5% for hysterectomy, and 3% for colectomy (all P <0.01). However, similar decreases were seen in the neighboring hospitals that did not have critical pathways or other specific efficiency initiatives.

CONCLUSIONS: Critical pathways were associated with a rapid reduction in postoperative length of stay after all five study procedures. Secular trends at nearby hospitals, however, produced comparable reductions for the three procedures available for comparison. These findings raise questions about the effectiveness of critical pathways in a competitive environment.