Health system strengthening: prospects and threats for its sustainability on the global health policy agenda.

In 2013, Hafner and Shiffman applied Kingdon's public policy process model to explain the emergence of global attention to health system strengthening (HSS). They questioned, however, HSS's sustainability on the global health policy agenda, citing various concerns. Guided by the Grindle and Thomas interactive model of policy implementation, we advance and elaborate a proposition: a confluence of developments will contribute to maintaining HSS's prominent place on the agenda until at least 2030. Those developments include (1) technical, managerial, financial, and political responses to unpredictable public health crises that imperil the routine functioning of health systems, such as the 2014-2015 Ebola virus disease (Ebola) epidemic in West Africa; (2) similar responses to non-crisis situations requiring fully engaged, robust health systems, such as the pursuit of the new Sustainable Development Goal for health (SDG3); and (3) increased availability of new knowledge about system change at macro, meso, and micro levels and its effects on people's health and well-being. To gauge the accuracy of our proposition, we carried out a speculative assessment of credible threats to our premise by discussing all of the Hafner-Shiffman concerns. We conclude that (1) the components of our proposition and other forces that have the potential to promote continuing attention to HSS are of sufficient strength to counteract these concerns, and (2) prospective monitoring of HSS agenda status and further research on agenda sustainability can increase confidence in our threat assessment.