These GHIs generally target specific diseases such as HIV/AIDS or malaria. Their influence is massive: in 2007 the three biggest (the Global Fund, PEPFAR, and GAVI) donated over $7.5 billion.
Yet this extremely detailed report tears into the GHIs for failing to evaluate their impact on country health systems.
"No robust prospective studies of the effects of GHIs on country health systems have been done."
GHIs are characterised by their focus on scaling up selected services that have proven to be effective in the past and by their use of performance-based assessment to deliver their interventions. It's sadly ironic that they have failed to collect the evidence on the effect they are having on their key partners.