“They want to understand why some generic drug classes aren’t being used as much as they could,” says lead investigator Jodi Segal, M.D., co-director of the Center for Drug Safety and Effectiveness at Johns Hopkins. “One goal of the project is to learn whether that decision stems more from patient demand or from doctor demand.”
The study, “Effect of Therapeutic Class on Generic Drug Substitutions,” will analyze drug use in the U.S. by therapeutic class and create predictors to help determine when generic or brand-name medications are more likely to be used by patients. The research will also make use of patient-reported concerns about generic drugs, by therapeutic class, to identify reasons patients might ask their doctors to prescribe generic drugs. It also will develop a method for prioritizing drug classes that would benefit from generic drug development.
Patent protection for a brand-name drug lasts an average of 20 years from date of filing. A generic drug can enter the market only after the brand-name patent or other marketing exclusivities have expired and FDA approval is granted. While the generics are molecularly identical to their brand-name counterparts, there can be subtle differences, such as the shape of a capsule, or the dyes or fillers incorporated.
Both patients and doctors may perceive larger differences, because many brand-name medications benefit from powerful marketing campaigns. Previous research has found some patients are suspicious of generic drugs, believing they are less effective or of lower quality than branded counterparts. State laws can also guide the choice between generic or branded drugs. The research will test the hypothesis that states requiring generic substitutions when appropriate have higher rates of generic drug use.
When patients opt for brand-name drugs instead of the generic equivalent, their insurance companies pay more, and typically the patients do as well. In 2013, 86 percent of drugs prescribed in the United States were generic, according to the FDA, yet generic drugs accounted for just 29 percent of the nation’s prescription drug costs. According to IMS Institute for Healthcare Informatics, spending on branded drugs accounted for 71 percent of U.S. prescription drug costs, or $232 billion.
“If the societal goal is to allow patients to access worthy medications while containing costs within the health care system, we need to understand why there is differential acceptance of generic drugs,” says Segal.
Researchers will analyze electronic medical records from Sutter Health and insurance claims data from Truven Health Analytics. These large data sets will yield information about written and pharmacist-filled prescriptions, providing insights into the drugs that are prescribed and the ones patients actually had filled. In particular, investigators will look at differences in generic usage rates between different classes of therapeutic drugs, including medications for heart disease, epilepsy or asthma. They will also take into consideration such factors as patients’ age and socioeconomic class.
Additionally, the researchers will analyze data from the FDA Adverse Event Reporting System, which collects patient-based complaints about drugs. Investigators will focus on reports that discuss adverse results after switching to a generic product.
The Johns Hopkins team is conducting the research in partnership with the Palo Alto Medical Foundation Research Institute, in California, which has access to and experience with the Sutter Health data.
The final step will be to convene a panel of colleagues and experts, including representatives of large generic drug manufacturing companies, to work together to develop a system for identifying and prioritizing drugs that are suitable for investment and development of a generic substitute.
Co-investigators are Sonal Singh and Matthew Daubresse of Johns Hopkins. The lead investigator in California is Robert J. Romanelli of the Palo Alto Medical Research Foundation, who is working with Vani Nimbal.