Surveillance bias and public reporting

This week’s JAMA has a commentary from Haut and Pronovost that’s worth a read, on the topic of surveillance bias. This is Epidemiology 101 for those of us who live and breath surveillance and prevention, but unfortunately it is not very well understood by patients and public policy makers. So when data like this garbage dump from Consumers Reports are released and generate media attention, more harm than good result. Good hospitals are unfairly maligned, and undoubtedly some hospitals that game their rates or just perform poor surveillance are rewarded. Call me a stupid consumer, but if I require ICU care and have to choose between Vanderbilt, Virginia Commonwealth, University of Maryland and one of these hospitals, I’m choosing one of the first three. Now I'm sure this list includes excellent hospitals, but I have no (zero) confidence in the data presented (i.e. I'm 'getting to zero' confidence).

We’ve blogged plenty about the challenges of public reporting and establishing a level playing field, so I’ll refer readers to these prior posts. As Haut and Pronovost point out, to ignore standardized, accurate and fair measurement (to include external validation) is both “reckless and unjust”. It is also true that “to be done appropriately, quality measurement is expensive”. Cheap shortcuts, like using ICD-9 coding data, simply prove the maxim that ‘you get what you pay for’.