During the past half-century, numerous advances
in medicine and public health have
been introduced into local health programs
throughout the world. The under-5 mortality
rate (the risk of death from birth until the
fifth birthday) in developing countries fell by
47% (from 167 deaths per 1000 live births
to 89 deaths per 1000 live births) between
1970 and 2001.1,2 The degree to which this
decline can be attributed to local health programs
is not well understood.3,4