1) Evidence synthesis helps ensure sound policies and investment in global health by basing decisions on reliable evidence from systematic reviews of research studies. 2) The Cochrane Infectious Diseases Group conducts systematic reviews on infectious diseases affecting developing countries. It currently has 17 editors, 700 authors from 55 countries, and has published over 500 reviews. 3) Reanalysis of a famous deworming study from Kenya that found benefits to nutrition and school attendance revealed major, moderate, and minor errors, calling into question the evidence used to justify contemporary deworming programs.