1. Epidemic Curves Sensitivity/Specificity

2. Epidemic Curve Time (since exposure) Number of New Cases

3. Notes on Epidemic Curves Sort by time to illness Think critically about the data (possible problems) Ask questions (or make assumptions) Similar to Survival Curve (see text, p492)

4. Survival from AIDS in Mths (p492 in text) Pt #Surv. Mths 12 0.9167 23 0.9091 36 46 0.800 57 0.857 610 715etc 815 916 1027 1130 1232 Hazard See Table 21.3 in Text (page 493) Survival Rate

5. Sensitivity/Specificity (p136 in text) Used in Screening or diagnostic Tests when there is a ‘gold standard’ Sensitivity: pr(+| ill) Specificity: pr(-| not ill) Suppose eating a food item is a ‘test’. If yes, the person should be ill. If no, not ill. Use ‘symptoms’ as the ‘gold standard’