The possibility that health care providers (HCP) might try to game the system and treat the chart when offered or forced to play the P4P game is well recognized and quite consistent with basic human nature.
Researchers from the Houston Veteran's Administration Hospital have published an article indicating that behavior of that type does in fact occur. Dr. Laura S. Peterson and her associates write in the August 15 2006 issue of the Annals of Internal Medicine.
They reviewed 16 articles and in 4 studies they found evidence of unintended effects-adverse selection and gaming or treating the chart to achieve financially rewarded goals. Importantly, for those of us who believe this entire P4P movement is motivated by a desire to save money, they found no evidence that these efforts are cost effective. Of course, lack of evidence does not necessarily mean evidence that they are not cost effective but the third party payers and CMS may at some point pull back if they are continue to be unable to show they there are cost savings to the payers. I hope so.