How Many RNs Does it Take to…

How many RNs does it take to change your star rating? That’s the topic of today’s post. (You thought this was going to be a joke about registered nurses and light bulbs, didn’t you?)

RN staffing hours have a huge effect on your star rating. Specifically the staffing score is about two thirds RN hours. The goal of this post is to help you understand how nursing hours effect your staffing star rating and how many hours it would take your facility to move from your current star rating to any other rating.

The staffing star rating is hardest bonus star to achieve. (Check out my previous post about the different ways facilities get star ratings.) In fact, you can get the staffing bonus star with either a 4 or 5 star staffing rating and it’s still less frequently awarded than the QM bonus star which can only be achieved with a 5 star QM rating.

How is the staffing star rating calculated?

(Feel free to skip this part if you just want to know about your facility.) There are two parts to the staffing rating: RN staffing and overall nursing staffing, which includes RNs. That means a change in RN hours affect both ratings. 

For each of the two ratings we calculate something called adjusted hours which are simply your reported RN hours divided by expected hours and then multiplied by the national average hours. The equation looks like this:


Your expected hours are based on the case-mix of your entire population. A RUG-IV RUG is calculated for everyone. Based on those RUGs we get an expected number of nursing hours. This information comes from the latest STRIVE study. (If you want to see the expected hours per RUG-IV RUG, check out page 20 of this document.)

The national averages are occasionally recalculated but as of this writing are 0.380417 for RNs and 3.228514 for total nursing hours.

Next, use your adjusted hours to look up star ratings from the table below. (This table is from the document I linked above.) 


Lastly, your stars for RN and Total are used to look up your overall staffing score from this table, which is from the same document:


Simple, right?

What about MY facility?

So let’s say you have a star rating of 5. How many RN hours could you lose and maintain that star rating? Or let’s say you have a 3 star rating and want to know how many hours it would take to get a 4 or even 5 star rating?

Since we know how star ratings are calculated, we can easily figure out how many hours it would take for your specific facility to get any star rating we want. Well almost any star rating. You can see from the table that if you have a very low number of LPN and aide hours, it isn’t possible to get 5 stars no matter the number of RN hours you add. Also you can only go so low with RN hours before you don’t get a score. You can see the exclusion rules in the document I previously linked. See page 8.


Let’s look at a specific example:

To the right is information for Meadow Park Health and Rehabilitation in Vidalia Georgia. (Randomly selected, I have no relationship with this building or anyone affiliated with it and I’ve never been there.) 

This building received 3 stars for staffing as of this writing. (yellow) They reported 0.611 RN hours per resident per day. (Also yellow)

IF they were to reduce the RN hours from 0.611 to 0.261 (orange) they would score 2 stars. That’s a reduction of 57%. Any lower than that and they’d get one star.

They could actually reduce RN hours by 52% and MAINTAIN the 3 star rating they already have. (blue)

What would it take for this facility to get to 4 staffing stars? Not much it turns out. Increasing RN hours by less than 2 percent would have done the trick. (green) What’s more interesting is this change from 3 to 4 staffing stars would have given Meadow Park Health a bonus star and turned the facility from 3 overall stars to 4.

A 5 star staffing rating would require an incredible 71% increase in RN hours and not net the facility anything other than a really impressive staffing star rating, and of course the intrinsic benefits of an extra RN around. (red) (The bonus star is for 4 or 5 staffing stars.) 

Now let’s look at yours!

I’ve done the calculations described above for every building that currently has a star rating. Just find your facility on the map and click the marker. (Be patient, the map might be slow to load. There are around 15 thousand SNFs on it.)  I highly recommend opening the map in it’s own window to make it easier. (click the tiny frame in the upper right corner of the map.) The map has 9 layers: 1 star, 2 star, 3 star (x3), 4 star (x3) and 5 star. 3 and 4 star are split into 3 layers because of limitations in the mapping tool. After you full-screen the map you can enable/disable layers as you’d like. 

If you have any questions about the mapping, the way I did the calculations, star ratings or anything else, contact me. I’d be happy to help you find your facility and interpret your numbers.








If you really were looking for a nursing joke: How many nurses does it take to screw in a light bulb?


None. They have the nursing students do it.