| Term | Definition |
| TB, malaria, HIV, diarrhea, respiratory infections | world's leading causes of death (infectious diseases) |
| heart complications, unknown, cancer | world's leading causes of death (besides infectious diseases) |
| retrospective and prospective | 2 types of analytical cause and effect studies |
| retrospective | look at those with and without disease and compare them |
| prospective | collect data over time before the disease begins and compare two groups |
| experimental | study of comparing a treated population (with vaccine etc.) and a placebo |