Does need matter? Needs assessments and decision-making among major humanitarian health agencies.

Disasters of physical origin, including earthquakes, floods, landslides, tidal waves, tropical storms, tsunamis, and volcanic eruptions, have affected millions of people globally over the past 100 years. Proportionately, there is far greater likelihood of being affected by such disasters in low-income countries than in high-income countries. Furthermore, low-income countries are in need of international assistance following disasters more often than high-income countries.