New Clinical Information and Physician Prescribing: How Do Pediatric Labeling Changes Affect Prescribing to Children?

This paper investigates the impact of new clinical information and pediatric labeling changes, induced by the FDA’s 1997 pediatric exclusivity provision, on physician prescribing to children. The policy, which offers firms extensions of market exclusivity in return for conducting clinical studies of existing drugs in children, was a response to the absence of pediatric data in most drug labels to inform pediatric prescribing. The policy led to a surge in the number of pediatric clinical studies and an increase in pediatric drug labeling changes, which reflect the new scientific information from those studies. However, there is little evidence about how the new information from these studies has affected physician prescribing to pediatric patients. Given that extensions of exclusivity are socially costly, evidence is needed to evaluate the social benefits of the exclusivity policy.

We use a difference in difference strategy to examine the extent to which the new clinical information in a pediatric drug labeling change affects physician prescribing to children. Using data for all pediatric drug labeling changes among new chemical entities approved from 1990 to 2007 and pediatric prescribing data from the National Ambulatory Medical Care Survey (NAMCS), we empirically examine how pediatric prescriptions respond to different types of labeling changes in comparison to adult prescriptions of comparator drugs (without labeling changes) in the same ATC class. One challenge associated with identifying the effect of the new information in the labeling change is controlling for alternative sources of information dissemination of clinical study results. Our analysis controls for the dissemination of pediatric study results in medical journals and in drug promotion using data from IMS Health and the medical literature.

Our results show that the new information when added to a drug's label did affect pediatric prescribing. We find that most pediatric exclusivity label changes lead to reductions in prescribing to children. We observed the greatest reduction in pediatric prescribing when the label indicates that a drug is not effective for children. Results also show that physicians prescribe fewer drugs to children when the label reveals new pediatric risk information. This evidence suggests that the pediatric labeling changes led physicians to reduce previous patterns of inefficient off label prescribing.