U.S. News and World Reports used to only rank medical schools according to one system, which was research rank. Research activity accounts for 30 percent of the ranking calculation. This category is divided into "Total Research Activity," based on the dollar amount of the National Institutes of Health research grants awarded to the medical school and its affiliated hospitals, and "Average Research Activity Per Faculty Member," based on the dollar amount of National Institutes of Health research grants awarded to the medical school and its affiliated hospitals per full-time faculty member. Thus, research rankings reward schools in which there is a faculty emphasis on conducting major medical research projects, such as at Duke University, Harvard University and Johns Hopkins University.
Based on the belief that the top research universities are not necessarily the best institutions for training primary-care physicians, U.S. News and World Reports added primary-care rank. Research activity metrics are not included in the primary-care ranking calculations, but there is instead a "Primary-Care Rate," worth 30 percent. Primary Care Rate measures the percentage of M.D. or D.O. school graduates entering primary-care residencies in the fields of family practice, pediatrics, and internal medicine. University of Washington and University of North Carolina, Chapel Hill, are examples of schools with high primary-care rankings.
There are several indicators that are included in both research rank calculations and primary-care rank calculations, but accord differing amounts of weight in each system. Research rankings emphasize quality assessment scores by residency directors and student selectivity scores (based on students' MCAT scores, GPAs and the school's acceptance rate). Primary care rankings emphasize peer quality assessment scores and the school's faculty-to-student ratio.
Fitzhugh et. al. proposed an alternative medical school ranking system, called social mission score. They argue that the basic purpose of medical schools is to educate physicians to care for the national population. To fulfill this goal, medical schools should have sufficiently high percentages of graduates who practice primary care, work in health professional shortage areas, and are from underrepresented minority groups. Social mission scores are calculated based on measuring graduates in each of these three categories. The medical school with the highest social mission score is Morehouse School of Medicine. Social mission scores are generally the highest among public and community based medical schools. They are inversely correlated with the National Institute of Health's funding patterns.