http://www.who.int/docstore/bulletin/pdf/2000/issue6/bu0585.pdf

The most frequently used bases for comparing international health care resources are health care expenditures, measured either as a fraction of gross domestic product (GDP) or per capita.It distinguishes measures of real resources, forexample human resources, medicines and medical equipment, from measures of financial resources such as expenditures. Measures of real resources are further subdivided according to whether their factor prices are determined primarily in national or global markets.