David B Ridley

• PhD
• Professor (Associate) at Duke University

Introduction Neglected diseases are a significant global health challenge. Encouraging the development of therapeutics and vaccines for these diseases would address an important unmet medical need. We propose a priority review voucher programme for the European Union (EU). The developer of a drug or vaccine for a neglected disease would receive a v...

During the initial phase of the COVID-19 pandemic, the Food and Drug Administration (FDA) halted inspections of most overseas drug manufacturing establishments. Looking at data from the period 2012-22, we observed steep declines in both foreign and domestic inspections in 2020. By 2022, numbers of inspections remained well below prepandemic levels,...

The COVID-19 global pandemic has devastated lives and economies. It has served as a reminder of how critical it is to invest in preventing and treating infectious diseases. Until the COVID-19 pandemic, the largest US government-sponsored reward for infectious disease drug and vaccine development was the Tropical Disease Priority Review Voucher prog...

Medicare reimburses health care providers for the drugs they administer. Since 2005, Medicare has reimbursed based on the past price of the drug. Reimbursement on past prices could motivate manufacturers to set higher launch prices because providers become less sensitive to price and because provider reimbursement is higher if past prices were high...

How do governments respond to other governments when providing a global public good? Using data from 2007 to 2014 on medical research funding for infectious and parasitic diseases, we examine how governments and foundations in 41 countries respond to funding changes by the US government (which accounts for half of funding for these diseases). Becau...

Many in the scientific community are concerned about the potential increase in prevalence of insect-borne diseases such as Chagas disease, Chikungunya, dengue fever, malaria, and Zika in the United States and around the world. Beyond vaccines and drugs to prevent and treat these diseases, a comprehensive approach to fighting these diseases should i...

Beginning in the mid- 2000s, the incidence of drug shortages rose, especially for generic injectable drugs such as anesthetics and chemotherapy treatments. We examine whether reimbursement changes contributed to the shortages, focusing on a reduction in Medicare Part B reimbursement to providers for drugs. We hypothesize that lower reimbursement pu...

U.S. federal and state governments rarely regulate healthcare price levels, but do regulate price changes for pharmaceuticals, hospitals, and health insurance. Previous research showed that limiting price increases can raise launch prices and reduce both profit and social welfare, assuming consumers are myopic. We show that with forward-looking con...

The U.S. Congress created the priority review voucher program in 2007 to encourage development of drugs for neglected diseases. Under the voucher program, the developer of a drug for a neglected or rare pediatric disease that is approved by the U.S. Food and Drug Administration receives a bonus priority review voucher for another drug. As of 2016,...

In 2007 the US Congress created the priority review voucher program to encourage the development of drugs for neglected diseases. Under the program, the developer of a drug that treats a neglected disease receives both a faster review of the drug by the Food and Drug Administration and a voucher for a faster review of a different drug. The develope...

To the Editor Dr Kesselheim and colleagues1 assessed the priority review voucher program, which rewards companies for US Food and Drug Administration (FDA) registration of treatments for rare pediatric or neglected diseases. We have a more optimistic view of the program.First, the authors wrote that “several more promising approaches exist,” includ...

In 2004 an Institute of Medicine report warned of vaccine shortages, raising concerns about disease outbreaks. More than a decade later, we looked for progress in reducing vaccine shortages. We analyzed data on vaccine sales and shortages reported by practitioners and patients to the Food and Drug Administration and the American Society of Health-S...

Drug development is costly, so drug makers need accurate estimates of sales potential. However, sales forecasts are often unreliable. Here, we present an analysis of data concerning entry order and promotional spending from a large sample of drug classes, to estimate peak market share while controlling for product quality.

SUMMARY Understanding competition in the US drug market requires knowing how sensitive demand is to prices. The relevant prices for insured consumers are copayments. There are many studies of copayment elasticity in the health literature, but they are of limited applicability for studies of competition. Because of a paucity of data, such studies ty...

In 2007, Congress created a fast-track review voucher at the US Food and Drug Administration (FDA) as a reward for approval of a drug for a neglected disease. The developer of a neglected-disease drug receives a transferable voucher for faster review of any other drug. Similar fast-track vouchers are being offered by other agencies including the US...

We estimate a model of drug demand and supply that incorporates insurance, advertising, and competition between branded and generic drugs within and across therapeutic classes. We use data on antiulcer drugs from 1991 to 2010. Our simulations show that generics and "me-too" drugs each increased consumer welfare more than $100 million in 2010, holdi...

This article sets out the context for the problem of insufficient affordable medicines to address health issues in developing countries. It also highlights some of the drivers of recent positive trends. It then detail policies and proposals that are intended to increase access to global medicines (i.e., those with a developed country market) by low...

Every year 1 billion people worldwide are affected by traditionally neglected diseases, such as malaria, tuberculosis, leishmaniasis, and lymphatic filariasis, which impose tremendous public health burdens. Governments, foundations, and drug manufacturers have, however, started to support development of new treatments. European Union Member States...

Theory predicts intense price competition results when firms cluster with rivals. Yet, strong evidence of clustering is found in previous empirical research. Researchers typically measure clustering by comparing observed location patterns to random assignment. The random assignment benchmark does not, however, account for zoning and geography and t...

"Why do businesses such as fast-food restaurants, coffee shops, and hotels cluster? In the classic analysis of Hotelling, firms cluster to attract consumers who have travel costs. We present an alternative model where firms cluster because one firm is free riding on another firm's information about market demand. One consequence of this free riding...

President Bush, the World Health Organization, and leading scholars have called for greater price transparency in health care. Prices are transparent when the buyer knows his or her price or knows prices paid by others, in advance. Transparent prices inform consumers of expected costs and reveal when sellers are charging high prices to poor people....

We analyze how rewards and penalties for follow-on drugs affect innovation, profits, and social welfare. Examples of policies that reduce the rate of return for follow-on drugs include the Orphan Drug Act and standard review at FDA, as well as the proposal of the former editor of the New England Journal of Medicine. Penalizing follow-on drugs is in...

Patents for several blockbuster biological products are expected to expire soon. The Food and Drug Administration is examining whether biologics can and should be treated like pharmaceuticals with regard to generics. In contrast with pharmaceuticals, which are manufactured through chemical synthesis, biologics are manufactured through fermentation,...

Infectious and parasitic diseases create enormous health burdens, but because most of the people suffering from these diseases are poor, little is invested in developing treatments. We propose that developers of treatments for neglected diseases receive a "priority review voucher." The voucher could save an average of one year of U.S. Food and Drug...

Withdrawals of high-profile pharmaceuticals have focused attention on post-approval safety surveillance. There have been no systematic assessments of spending on postapproval safety. We surveyed drug manufacturers regarding safety efforts. Mean spending on postapproval safety per company in 2003 was 56 million dollars (0.3 percent of sales). Assumi...

To estimate rates of non-adherence for statins following implementation of a preferred drug list (PDL). A retrospective cohort study. A difference-in-difference-in-difference approach was used to estimate the impact of a PDL on the use of statins in an Alabama Medicaid population. The PDL restricted access to certain branded medications and imposed...

Pharmaceutical manufacturers have increased the availability of their products and sometimes increased their own financial returns by charging lower prices outside of the US and by discounting to lower-income patients in the US. Examples include discounted HIV-AIDS drugs in developing countries and pharmaceutical manufacturers’ discount cards in th...

The Internet provides healthcare consumers with more information about available prices and provides pharmaceutical manufacturers with more information about consumers' willingness to pay. The former effect tends to undermine price differences while the latter tends to support them. We believe that the former effect will dominate and that the Inter...

We conducted a descriptive analysis of data from the Hospital Cost Report Information System from 1985 through 1997 on nonfederal, short-stay hospitals in the United States with 12-month reporting periods and valid data for the primary outcomes. The main outcome measures were change in number of beds, inpatient days, overhead cost per bed, and over...

Economists generally assume that zoning decreases competition, but we provide theory and evidence that zoning can have the opposite effect. Zoning keeps firms away from homes in order to protect home values. Preventing firms, such as liquor stores and gasoline stations, from locating near homes forces those firms closer together, increas-ing compet...