| Objective. This study aims to quantify the return from investing an additional one billion dollars in cumulative funding for the National Institutes of Health (NIH) in terms of increased pharmaceutical research and development (R&D) as indicated by annual numbers of new drugs per year entering Phase I clinical trials. The study also aims to determine how the return on investment, as define above, varies across individual Institutes of the NIH.; Data. The comprehensive dataset needed to meet this objective was constructed by combining data from many sources on NIH funding, counts of drugs beginning clinical trials between 1983 and 1999, industry research spending, insurance coverage, drug sales, counts of drugs in later stages of R&D, perceived medical need for disease treatments, indicators for FDA incentives, and the number of companies involved in developing each drug. The drugs were grouped into categories corresponding to each Institute, which resulted in drugs targeting diseases with the majority of their research funding coming from the same NIH Institute grouped together.; Methods. The primary model was a log-linear model of the counts of drugs and cumulative Congressional appropriations for NIH, discounted 3% annually. Sensitivity analyses were performed using covariates representing potential confounding effects. Sensitivity analyses were also done using four other forms of NIH funding: (1) using a discount rate of 5% rather than 3%, (2) using annual appropriations rather then cumulative appropriations, (3) excluding administrative and training grant appropriations from the total appropriations, and (4) using non-AIDS research appropriations. The study also examined the sensitivity of the findings to insurance coverage, industry research spending, pharmaceutical sales revenue, potential competing pharmaceuticals, FDA drug development incentives, and the companies involved in developing each drug.; Results. This study found that, during the 1980s and 1990s, each additional billion dollars in cumulative Congressional NIH appropriations (discounted 3% annually) resulted in an average of 5.3 new drugs ({dollar}188.7 million/drug) entering Phase I clinical trials across all disease categories. The number of new drugs entering Phase I clinical trials per billion dollar increase in NIH funding varied markedly across Institutes, ranging from 23.8 ({dollar}42.0 million/drug) for NIAMS, to less than 1 (>{dollar}1 billion/drug) when NIMH, NIDA, and NIAAA were combined. Modeling showed that, in the 1980s and 1990s, the time lag between increases in cumulative Congressional appropriations and increases in new drugs entering Phase I clinical trials was estimated to be an average of 11.1 years across Institutes, with wide variation in time lags across Institutes, ranging from 18 years for NIDDK to 4 years for the combination of NIMH, NIDA, and NIAAA.; Conclusions. Increases in cumulative NIH funding correlates strongly with the number of new drugs entering Phase I clinical trials, but the wide variation in the return across individual Institutes raises questions about the most effective way allocate NIH funding to maximize impact on pharmaceutical research and development by disease categories. |
