Date of Award


Document Type


Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Joseph S. Ross


Importance: Generic drugs play an essential role in the US healthcare system, providing less costly alternatives to branded drugs that are equally effective and safe. The US Food and Drug Administration (FDA) regulatory policies influence the standards for generic drug approval. In 2017, the FDA instituted several initiatives to promote generic drug approval, particularly focused on those with limited competition.

Objective: To determine whether the initiatives begun by FDA in 2017 were associated with greater numbers of approvals of generic drugs with limited generic competition and histories of drug shortage.

Study Sample and Design: We conducted a cross-sectional study of new drug applications (ANDA) approved by FDA during two one-year periods: July 1st, 2016 to June 30th, 2017 (before the initiatives) and January 1st, 2018 to December 31st, 2018 (after the initiatives). ANDAs were also characterized on the basis of their initial approval year, priority review status and orphan designation status for the original new drug, World Health Organization (WHO) essential medicine status, therapeutic area, drug complexity.

Main outcomes and measures: We determined (1) generic competition at the time of ANDA approval; (2) history of drug shortage during the five years before ANDA approval.

Results: A total of 1,410 ANDAs were identified, 661 prior to the FDA’s initiatives, 749 afterwards. Overall, there were 336 (23.8%) ANDAs originally approved with priority review status, 183 (13.0%) ANDAs previously approved with orphan drugs status. 262 (18.6%) ANDAs were listed as essential medicine by WHO, and 265 (18.8%) generic approvals were categorized as complex generic drugs. In the pre-period, 234 (35.4%) of the ANDAs approved were determined to have limited competition (≤3 ANDAs), as compared to 237 (31.6%) afterwards (p=0.14). Similarly, 242 (36.6%) of the ANDAs approved in the pre-period had been in shortage during the five years before ANDA approval, as compared to 282 (37.7%) afterwards (p=0.69). In multivariate analysis, approval of generics with limited competition was significantly less likely during the period after the FDA’s initiatives when compared to before (OR=0.76; 95% CI, 0.60-0.97; p=0.02), but there was no significant difference in the approval of generics with histories of drug shortage (OR=1.09; 95% CI, 0.86-1.38; p=0.46).

Conclusion and relevance: The FDA’s initiatives in 2017 to promote generic drug approvals had limited impact on the approval of ANDAs for drugs that lacked generic competition and had histories of drug shortage. Additional efforts are needed to promote approval of generic drugs with limited competition.


This thesis is restricted to Yale network users only. It will be made publicly available on 08/28/2021