What PPH measures
PPH is patients seen divided by provider hours worked. An ED that sees 60 patients in a day with 24 provider hours runs at 2.5 PPH. It measures workload per provider, averaged over whatever period you pick.
The usual range
A widely cited ACEP Now article on ED staffing puts the recommended range at 1.8 to 2.8 patients per provider per hour, with an inflection point around 2.1 to 2.2, past which more coverage is needed.1 Those figures describe emergency physicians and APPs across a shift. They don't include the wait a patient sees at 9pm.
Why waits climb so fast
Think of one provider who spends 20 minutes on each patient. That provider can see three patients an hour at most. At 1.5 patients an hour they're busy half the time, so a new patient usually finds them free. At 2.8 an hour they're busy more than nine minutes out of ten. Nearly every patient finds a line, and one long visit backs up everyone behind it.
Workload rises in a straight line. Waiting doesn't. Here's one MD, 24 hours a day, with visits averaging 20 minutes, run for a simulated year at each arrival rate.
| Patients per hour (PPH) | Share of time busy | Average wait |
|---|---|---|
| 1.5 | 50% | 13 min |
| 2.0 | 67% | 26 min |
| 2.2 | 73% | 37 min |
| 2.5 | 83% | 66 min |
| 2.8 | 93% | 190 min |
Example assumptions: steady arrivals, random around the hourly average; 20-minute average visit that varies from patient to patient. "Share of time busy" is arrivals times 20 minutes, divided by 60.
Going from 2.0 to 2.5 PPH is a 25% increase in workload. In this example the average wait goes from 26 to 66 minutes. The last step, from 2.5 to 2.8, takes it to 190.
Team size changes the answer
The same PPH gives a different wait depending on how many providers share the line. With more providers, the chance that all of them are tied up at once drops, so patients get through faster at the same workload per provider.
| Providers on duty | Patients per hour | PPH | Average wait |
|---|---|---|---|
| 1 | 2.5 | 2.5 | 66 min |
| 2 | 5 | 2.5 | 29 min |
| 3 | 7.5 | 2.5 | 20 min |
All three run at 2.5 PPH. One provider alone averages a 66-minute wait; three providers together average 20. That's why a PPH target that works at noon, with three providers on, can leave the overnight provider working alone with a long line.
How to use PPH
- Use it as a first check on total provider hours for a day or a shift.
- Don't use it to set hour-by-hour coverage. Small overnight teams need a lower PPH than large daytime teams to give the same wait.
- Check the hours that matter by running them. Enter your arrivals by hour and staffing, and look at the wait at each hour, not the daily average.
For a side-by-side of ratio tools and simulation, see staffing calculator vs. staffing simulation.
Questions
What is a good patients per provider per hour for an emergency department?
An ACEP Now article on ED staffing cites 1.8 to 2.8 patients per provider per hour, with more coverage needed past about 2.1 to 2.2. The right number for a given hour depends on visit length and how many providers are on together.
What is the difference between PPH and utilization?
PPH counts patients per provider hour. Utilization is the share of time a provider is busy, which is PPH times the average visit time. The same PPH means higher utilization when visits are longer.
Does the same math apply to urgent care?
Yes. Urgent care visits are usually shorter, so providers can see more patients an hour, but waits still climb steeply as providers approach full use. See the urgent care staffing guide.
Sources
- Staffing an ED Appropriately and Efficiently, ACEP Now, August 1, 2009 (Kirk B. Jensen, MD)