How do I improve OR utilization?

OR utilization is measured as wheels-in to wheels-out time as a percentage of available block time. The three highest-impact improvements are: reducing first-case start delays (average 18 minutes nationally), accurate case duration estimation (most facilities underestimate by 12–15%), and real-time turnover tracking with a target of 25 minutes between cases. AORN benchmarks a target utilization rate of 85%.

First-case start delays are the most addressable OR efficiency problem. The national average is 18–22 minutes per operating room per day, driven by three common causes: patient not yet on the surgical floor at wheels-in time, surgical consent not completed pre-operatively, and anesthetic pre-assessment delays requiring same-morning chart review. Each OR that loses 20 minutes per day loses 1.7 hours per week — 88 hours per year per room. At a contribution margin of $1,200 per OR-hour, a single operating room with consistent first-case delays loses over $100,000 in annual contribution margin.

Case duration estimation is a systematic rather than random problem. OR scheduling systems use mean historical duration by procedure and surgeon, which consistently underestimates complex cases in the right tail of the distribution. Using 75th-percentile duration for scheduling reduces list overruns — the cascading cancellation of final cases caused by schedule overflow — by approximately 40%. Turnover time, the gap between last patient leaving and next patient entering, averages 32–40 minutes at most hospitals against a 25-minute benchmark. The primary cause is diffuse accountability: no single role owns the full turnover sequence, so delays in any one step accumulate without triggering escalation.

OR utilization is almost universally reported as a daily or weekly average at the room or service line level. This aggregate conceals the intra-day pattern that is the actual operational problem: first case starts 20 minutes late, turnover accumulates 8 extra minutes per case, and the last case of the day is cancelled at 4:30 pm. Each of these events appears in isolation as an anomaly. Reported together across time, they reveal a systematic efficiency deficit that the average obscures.

Block utilization — the percentage of allocated block time actually used by the owning surgical group — frequently shows at 82–87% because unused blocks are released to other surgeons in the final 48 hours. This looks efficient in aggregate. The hidden finding is that the releasing pattern creates scheduling uncertainty for the non-block surgeons who fill those late-release slots, contributing to the case preparation delays that cause first-case overruns the following week.

Implement a first-case on-time start dashboard that tracks readiness by 30-minute intervals before wheels-in: patient on floor by T-60, consent complete by T-45, anesthesia assessment complete by T-30. Making these milestones visible to OR leadership creates accountability without requiring policy changes. Practices that implement real-time first-case readiness monitoring reduce first-case delays by 50–65% within 90 days.

Shift case duration scheduling to the 75th-percentile duration for each surgeon-procedure combination using the prior 12 months of actual duration data. Pair this with a real-time turnover tracking tool — ideally a visible scoreboard in the OR corridor — that shows current turnover time against the 25-minute target for every room simultaneously. Visible real-time performance against target is more effective than retrospective reporting for turnover improvement because it enables mid-session course correction.