Patient Satisfaction Scores
After the hospital at which I used to work began using Press Ganey last year, I researched the issues about validity and statistical methods Press Ganey used that didn’t seem right to me.
After reviewing Press Ganey documents, things still didn’t seem right.
For example, one Press Ganey document (.pdf file) trying to explain away small sample sizes shows that with a sample size of 25, the standard error approximates 20. During an interview with a Press Ganey researcher, I was told that Press Ganey seeks to have a standard error of 2 or less. When the sample size increases to 50, the standard error approximates 14 – still seven times more than Press Ganey’s goal. A sample size of 100 only decreases standard error to roughly 10. Statistically significant?
Another Press Ganey document (.pdf file) provides scripts for hospital administrators to use when physicians object to Press Ganey’s statistical methods. Tell the doctors that you’ll put them in touch with the Ph.Ds at Press Ganey headquarters. “Rarely does a physician pursue the matter further when offered to speak to someone knowledgeable in statistics,” the documents says.
I did speak to Press Ganey statisticians. The answers they had to my questions really didn’t cut it.
When things still didn’t make sense, I interviewed some statisticians at St. Louis University and then co-published a couple of articles about patient satisfaction and Press Ganey in EP Monthly, the magazine where I have been a contributing author for more than 10 years. Links below.
Didn’t seem to have much of an effect upon the misuse of the statistics.
I also engaged in a point-counterpoint with another physician about whether patient satisfaction scores are useful. A heavily edited version of that article appears on EP Monthly here. I submitted the original version of the article to Kevin, MD and he graciously agreed to post it on his blog.
I have a couple of other articles about Press Ganey to write in the next few months. I also received some raw data about a survey that asked doctors and patients about patient satisfaction surveys. I plan to publish that study later this year.
Will post all the articles here when I finish them.