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Relative Influence on Total Cancelled Operating Room Time from Patients Who Are Inpatients or Outpatients Preoperatively

Dexter, Franklin MD, PhD*; Maxbauer, Tina; Stout, Carole MS, BSN, CNOR; Archbold, Laura BSN, MBA§; Epstein, Richard H. MD, CPHIMS

doi: 10.1213/ANE.0000000000000118
Economics, Education, and Policy: Research Report

BACKGROUND: In previous studies, hospitals’ operating room (OR) schedules were influenced markedly by decisions made within a few days of surgery. At least half of ORs had their last case scheduled or changed within 2 working days of surgery. In the current investigation, we studied whether many of these changes were due to patients who were admitted before surgery. We differentiated these “inpatients” from “outpatients” having ambulatory surgery or admitted on the day of surgery.

METHODS: From 21 facilities of a nonacademic health system throughout the United States, N = 5 eight-week periods of cancellation data were obtained. From an academic hospital, N = 8 thirteen-week periods of cancellation data were obtained, including detailed audit data with timestamps of the entire scheduling/rescheduling/cancellation history for each case.

RESULTS: (1) In the non-academic health system, outpatients accounted for 1.6% ± 0.1% (SEM) of the scheduled minutes that were cancelled, whereas inpatients accounted for 8.1% ± 0.4%. Consequently, even though inpatients represented much less than half the total scheduled minutes of surgery (16.2% ± 0.5%, P < 0.0001), they accounted for approximately half of the total cancelled minutes (overall P = 0.55, 49% ± 2%; hospitals only P = 0.062, 57% ± 3%). (2) In the nonacademic health system, each 10% increase in a facility’s percentage of outpatients making a physical visit to a preoperative clinic (versus only a preoperative phone call) was associated with a 0.0% ± 0.1% absolute decrease in cancelled minutes (P = 0.58). (3) In the academic hospital, inpatients accounted for 22.3% ± 0.4% of the scheduled minutes but most of the total cancelled minutes (70% ± 2%, P < 0.0001). Slightly more than half the total inpatient cancelled minutes (54% ± 1%, P = 0.006) were due to cases scheduled within 1 workday prior to the day of surgery (e.g., Friday for Monday, Monday for Tuesday). During this period, inpatient cancellation rates, measured in minutes, were several-fold larger than outpatient rates (P < 0.0001).

CONCLUSIONS: Facilities can achieve a ≤2% cancellation rate for patients who are outpatient preoperatively with very few attending a preoperative clinic, when a virtual evaluation is carried out by phone. At least half of the cancelled time at health systems and hospitals is attributable to inpatients, and these patients principally are scheduled within 1 workday of the day of surgery. This is why there are so many changes to the OR schedule within 1 workday before the day of surgery. Hospitals should evaluate the cost-effectiveness of earlier assessments of inpatients. In addition, scheduling office decision-making within 1 workday before surgery should be based on statistical forecasts that include the risks of cancellation and of inpatient add-on cases being scheduled. Hospitals should monitor the performance of their perioperative managers with respect to such behavior.

From the *Department of Anesthesia, Division of Management Consulting, University of Iowa, Iowa City, Iowa; Trinity Health, Waterford; Trinity Health, Lake Orion; §Trinity Health, Livonia, Michigan; and Department of Anesthesiology, Jefferson Medical College, Philadelphia, Pennsylvania.

Accepted for publication December 18, 2013.

Funding: Departmental funding.

Conflict of Interest: See Disclosures at the end of the article.

Reprints will not be available from the authors.

This paper will be presented at the INFORMS Annual Meeting 2014 in San Francisco November 2014.

Address correspondence to Franklin Dexter, MD, PhD, Department of Anesthesia, Division of Management Consulting, University of Iowa, 200 Hawkins Dr., 6JCP, Iowa City, IA 52242. Address e-mail to or

© 2014 International Anesthesia Research Society