How Many Nurses on Call?

Two nurses on call cost $624 on a normal night. Across ten thousand simulated nights they average $808, and the worst reaches $3,396, which is the number the stipend line never shows.

Nursing Intermediate Monte Carlo Pro engine

After you install, this is the model to open.

How Many Nurses on Call?

  1. In your spreadsheet, click the Sortia icon in the strip of icons down the right-hand edge. No strip? Click the arrow at the bottom-right to open it. You can also use Extensions, then Sortia, then Open Sortia.
  2. Click Start from a template and put that name in the search box.
  3. Pick the card with that name and click Load this template. It arrives on a new tab with real numbers already in it.

This one runs on a Pro engine, and every free install includes five full-quality runs on your own numbers, shared across all five Pro engines rather than five for each. After that, Pro is $199/year.

What it does

This is the newsvendor problem wearing scrubs. Hold too few nurses on call and the shifts nobody fills go to mandatory overtime at $756 each. Hold too many and you pay a stipend to people who go back to bed. The sheet holds two, on a night when one nurse calls off: $120 of stipend, one called in at $504, nothing uncovered, $624 all in. A perfectly ordinary night, and if you budget from it you will be wrong.

Click Run with call-offs drawn from the distribution in the panel. The average night costs $808, not $624, because the median night is cheap and the bad ones are very expensive. The maximum across ten thousand nights is $3,396. Shifts left uncovered average 0.21, which sounds like almost nothing until you notice the maximum is three, and three uncovered shifts is not a budget line, it is a unit running unsafely.

The shape here is the whole lesson: the median tells you what a night looks like and the mean tells you what the year costs, and on a cost that is skewed like this one they are $184 a night apart, which is about $67,000 a year on one unit. Budgeting off a typical night underfunds cover by roughly a quarter, every year, in a way that looks like an overspend rather than a bad estimate.

Change nurses held on call to three and rerun, then to one. What you are looking for is not the cheapest average, it is the point where uncovered shifts stop reaching three, because that tail is what you are actually buying insurance against. Two things it does not model. Call-offs are not independent: a norovirus outbreak or a bad roster takes several people at once, and the discrete distribution here treats each night as a fresh draw, so the true tail is fatter than what you see.

And it assumes an on-call nurse always answers, which anyone who has run a night shift knows is optimistic. To make it yours, replace the stipend, the shift pay and the overtime cost, and build the call-off distribution from your own last three months rather than the one here.

The model

It arrives on a tab called Template: How Many Nurses on Call:

On-call cover for one night, 24 rostered shifts
Nurses who call off1
Nurses held on call2
On-call stipend each, whether used or not60
Shift pay if one is called in ($)504
Mandatory overtime per shift ($)756
On-call nurses actually used1
Shifts still uncovered (count)0
Stipend cost120
Called-in shift cost504

plus 3 more rows on the sheet.

Once it is in your sheet

  1. The model arrives with real numbers in it and runs as it stands, so you can press the button first and understand it second.
  2. Change the numbers to yours. The sheet marks which cells are inputs and which hold formulas, and most labels carry a note explaining the row.
  3. Press the run button at the bottom of the panel. It is labeled for the tool you are in, and the result lands on its own tab, with a written reading of it beside the figures.

Never used Google Sheets? Start here goes the whole way, in seven steps, and assumes nothing.

Next question

Every model like this one, and the method behind them: Monte Carlo simulation.