getty

The Centers for Medicare and Medicaid Services have been publishing quality ratings for nursing homes since 2009.

They are known generally as “star ratings,” because the nursing homes are rated from a low of one star to a high of five stars.

A recent study tried to assess the value of the star ratings and develop guidelines for how the public can interpret and use them.

One finding is that the ratings are volatile. Very few nursing homes maintained the same star rating from year to year. The researchers believe the high volatility reduces the value of the ratings.

There were two sources of volatility.

Some of the volatility was specific to the facilities. The study concluded that over the long term, the volatility in ratings reflected changes in the quality of care at the facilities.

But there also was significant short-term volatility.

Roughly half of nursing homes with one-star ratings gained one or more stars within six months while about half of those with five-star ratings lost one or more stars within six months.

The researchers doubted this ratings volatility reflected real volatility in the quality of care. Other issues related to the factors used to compile the ratings were the likely cause.

The ratings also had what the study called general volatility. Changes in the ratings methodology caused abrupt changes in the overall distribution of star ratings. At times, the ratings changed quickly from one month to the next.

The study concluded that these changes were unrelated to the quality of care and reduce the usefulness of the ratings.

Another finding was that state laws on minimum staffing levels at nursing homes were mostly irrelevant to the quality of care and star ratings. Actual staffing hours in most nursing homes significantly exceeded state-mandated minimum staffing levels.

But there was a strong association between the staffing levels at a nursing home and the star ratings. Each additional hour of care per resident per day led to an increase in a facility’s star rating.

Another problem with the ratings is the CMS advises that a three-star rating is “average.” The study found that is not the case.

Because of the volatility of the ratings, during some periods a three-star rating was above average. In other periods it was below average.

The average also varied greatly between states. A star rating that is average in one state could be above or below average in other states.

The volatility of the average makes it difficult to assess a facility’s performance over time.

A nursing home might maintain a three-star rating consistently over several years. But within that nursing home’s state, the rating might be below average in some years and above average in other years.

One consistency the study did find is that non-profit nursing homes tend to have higher ratings than for-profit facilities.

In 2025, only 14% of one-star nursing homes were operated by non-profit entities while 47% of five-star nursing homes were operated by non-profits.

The researchers found this relationship became stronger over time.

The study concludes that the ratings system should be modified to reduce volatility and other issues. In the meantime, users should be aware of the shortcomings of the ratings and the difficulty comparing ratings over time.