Epidemiology Congresses XIX, XX and beyond: back to the future of population health.

The XIX World Congress of Epidemiology discussed 'Changing populations, changing diseases: epidemiology for tomorrow's world' and was able to set a benchmark for the current state for the science of population health. However, 'changing populations and changing diseases' mean that robust epidemiological enquiry is, and will continue to be, required, but most importantly, it must remain objective and relevant to the public it serves. We look forward to further discussion on population health science in tomorrow's world in three years time at the XX World Congress of Epidemiology in Anchorage, Alaska.