NIH and National Foundation Expenditures For Sickle Cell Disease and Cystic Fibrosis Are Associated With Pubmed Publications and FDA Approvals

Sickle cell disease (SCD) and cystic fibrosis are both rare inherited diseases most often diagnosed in the United States by newborn screening. Early diagnosis and treatment have led to substantial improvements in survival, but adult mortality remains high with median survival of 40 to 45 years for sickle cell anemia and 35 to 40 years for cystic fibrosis. Disparities in funding between these two diseases of similar severity have been long recognized, but the relationship between funding and research productivity has not been rigorously evaluated. We hypothesized that expenditures by the NIH and the national foundations for these diseases would be associated with the number of publications indexed in PubMed, active clinical trials, and FDA approvals.

We estimated disease-specific funding and number of career development awards using NIH RePORT (http://www.report.nih.gov/categorical_spending.aspx) and the Form 990 financial reports for expenditures by year for the Sickle Cell Disease Association of America and the Cystic Fibrosis Foundation and Cystic Fibrosis Foundation Therapeutics, Inc. We calculated expenditures per individual using published estimates of the number of people with SCD (89,079) and cystic fibrosis (30,000) in the United States. We developed a comprehensive search strategy with a medical informationist to identify relevant publications in PubMed and new postings of clinical trials (clinicaltrials.gov) by disease. We reviewed FDA approvals from 2009 to July 2013 to identify indications for SCD or cystic fibrosis.

Funding per affected individual was 7.6 (2010) to 11.4 fold (2011) greater for cystic fibrosis than SCD and included a 3.5-fold higher NIH funding and 370 (2010) to 440 fold (2011) higher national foundation funding. NIH career development awards were similar for the two diseases despite nearly 3-fold more individuals affected by SCD. There were nearly twice as many publications and slightly more new listings of clinical trials for cystic fibrosis. No drugs were approved between 2010 and July 2013 for the treatment of SCD compared with 5 for cystic fibrosis.

We confirmed widely disparate NIH and national foundation funding per individual affected by SCD and cystic fibrosis. Research productivity as measured by articles indexed in PubMed, new clinical trials, and new drug approvals were substantially higher for cystic fibrosis, despite similar severity to SCD and many fewer affected individuals in the United States. This likely reflects the increased financial resources available for research and quality improvement efforts.