1. Correlational Studies for Drug Effects Alec Walker October 2014 1

2. Correlational Studies  Population frequency  Population exposure  Inference on association  The problem of common cause

3. How we evaluate causal connections 3 Theory Prediction Experiment Data

4. Rheumatic Heart Disease at the House of the Good Samaritan, Boston, 1921-1920 4 Massell BF et al. N Engl J Med. 1988;318(5):280-6

5. Theories for Drug Safety  Case Reports  Correlations  Analogy  Animal Experience  Rumor

6.  Case Fatality Clinical Course of Rheumatic Carditis Loss of Murmurs in rheumatic carditis patients in Boston

7.  Case Fatality A General Theory Loss of Murmurs in rheumatic carditis patients in Boston Penicillin availability

8.  Case Fatality A Broader Prediction Loss of Murmurs in rheumatic carditis patients in Boston Penicillin availability National declines in mortality from scarlet fever and its complications

9.  Case Fatality A Broader Prediction Loss of Murmurs in rheumatic carditis patients in Boston Penicillin availability National declines in mortality from scarlet fever and its complications Examine rates

10. US Mortality from Strep and RF 10 Massell BF et al. N Engl J Med. 1988;318(5):280-6

11. Correlational Studies  Pay attention to the unit of observation  Risk or rate is typically the metric  Does observation unit stand as a proxy for exposure?  Does observation unit stand as a proxy for other variable characteristics that predict outcome? Yes  Confounding (“ecological fallacy”) No  Instrument

12. Suicide v. CCBs in Sweden

13. Thank You!