Correlational Studies for Drug Effects

1. Correlational Studies for Drug Effects Alec Walker October 2014

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

3. How we evaluate causal connections Theory Prediction Data Experiment

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

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

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

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

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

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

10. US Mortality from Strep and RF MassellBF 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!