Cause

1. RR = 7 Cause Is this association causal? Detectives in the Classroom – Investigation 3-2: Cause

2. Hypotheses 1 How is this disease distributed? 2 Is there an association? 3 Is the association causal? 4 What should be done to prevent the disease? 5 Did the prevention strategy work? Where are we and where are we going? What’s my hypothesis? Did the exposure and the disease turn up together? Why did the exposure and the disease turn up together? Detectives in the Classroom – Investigation 3-2: Cause

3. No Outcome Total Outcome Exposure b a d c No Exposure Is the association causal? Detectives in the Classroom – Investigation 3-2: Cause

4. IS ASSOCIATED WITH IN Is the association causal? Detectives in the Classroom – Investigation 3-2: Cause

5. Review What do epidemiologists and mean when they say that two things, an exposure a disease, are associated with each other? Detectives in the Classroom – Investigation 3-2: Cause

6. No Outcome Outcome Exposure No Exposure Review Relative Risk Risks Count % or a b c d 10% or Compare Divide What do epidemiologists mean when they say two things, an exposure and a disease, are associated with each other? Detectives in the Classroom – Investigation 3-2: Cause

7. Relative Risk No Outcome Outcome Count 100 100% 100 0 100 Exposure 100 100 1 1% 1 99 100 No Exposure 100 Compare Divide Review Risks or a b c d or Did the exposure and the outcome turn up together? Were the exposure and the outcome associated? Detectives in the Classroom – Investigation 3-2: Cause

8. Relative Risk No Outcome Outcome Count 30 30% Exposure 30 70 100 100 1 30 30% No Exposure 30 70 100 100 Compare Divide Review Risks or a b c d 90 or Did the exposure and the outcome turn up together? Were the exposure and the outcome associated? Detectives in the Classroom – Investigation 3-2: Cause

9. Relative Risk No Outcome Outcome Count 30 30% Exposure 30 70 100 100 3 10 10% No Exposure 10 90 100 100 Compare Divide Review Risks or a b c d 90 or Did the exposure and the outcome turn up together? Were the exposure and the outcome associated? Detectives in the Classroom – Investigation 3-2: Cause

10. Review 1. Cause 2. 3. 4. 5. Detectives in the Classroom – Investigation 3-2: Cause

11. Review Detectives in the Classroom – Investigation 3-2: Cause

12. Review Epi Talk Cause Anything that produces an effect. Detectives in the Classroom – Investigation 3-2: Cause

13. 1 DZ NoDZ X NoX Identify the cells of the 2 x 2 table in which there would be people if the exposure caused the disease. 2 x 2 Table a a bc d d Detectives in the Classroom – Investigation 3-2: Cause

14. Cigarette Labels Detectives in the Classroom – Investigation 3-2: Cause

15. Cigarette Labels “… Smoking Causes Lung Cancer ….” Detectives in the Classroom – Investigation 3-2: Cause

16. 2 NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes Label a 2 x 2 table to test the hypothesis that cigarette smoking causes lung cancer. Cigarette smoking causes lung cancer. a bc d Detectives in the Classroom – Investigation 3-2: Cause

17. NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes Cigarette smoking causes lung cancer. a b a bc d c d Label a 2 x 2 table to test the hypothesis that cigarette smoking causes lung cancer. Detectives in the Classroom – Investigation 3-2: Cause

18. NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes Cell b … anything that produces an effect. b a bc d Smoking Causes Lung Cancer Label a 2 x 2 table to test the hypothesis that cigarette smoking causes lung cancer. Detectives in the Classroom – Investigation 3-2: Cause

19. NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes Time Cigarette smoking causes lung cancer. … anything that produces an effect. b a bc d Smoking Causes Lung Cancer X DZ Detectives in the Classroom – Investigation 3-2: Cause

20. AIDS No AIDS HIV No HIV Time HIV causes AIDS. … anything that produces an effect. b a bc d HIV Causes AIDS HIV AIDS Detectives in the Classroom – Investigation 3-2: Cause

21. NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes Time Cigarette smoking causes lung cancer. … anything that produces an effect. b a bc d Smoking Causes Lung Cancer Cigarettes Lung Cancer Detectives in the Classroom – Investigation 3-2: Cause

22. NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes X + X causes DZ. … anything that produces an effect. b a bc d Smoking Causes Lung Cancer X DZ Detectives in the Classroom – Investigation 3-2: Cause

23. NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes Genetic Susceptibility + Cigarette smoking causes lung cancer. … anything that produces an effect. b a bc d Smoking Causes Lung Cancer Cigarettes Lung Cancer Detectives in the Classroom – Investigation 3-2: Cause

24. No Measles Measles Measles Virus Measles Virus Causes Measles No Measles Virus No Immunity + Measles Virus Measles Measles virus causes measles. … anything that produces an effect. b a bc d Detectives in the Classroom – Investigation 3-2: Cause

25. 1. NoLung Cancer Lung Cancer a bc d Smoked Cigarettes Did Not Smoke Cigarettes b 2. X X + + Time Time Time 3. X causes DZ. X DZ X DZ X DZ Detectives in the Classroom – Investigation 3-2: Cause

26. NoLung Cancer Lung Cancer Smoked Cigarettes Did Not Smoke Cigarettes X Lung Cancer DZ X X Cell c … anything that produces an effect. Smoking Causes Lung Cancer a bc d c Cigarettes Asbestos Radon Detectives in the Classroom – Investigation 3-2: Cause

27. 3 DZ NoDZ X a bc d NoX Label the 2 x 2 table and identify the cells in which there would be people, if the exposure caused the disease. X causes DZ. Detectives in the Classroom – Investigation 3-2: Cause

28. 4 DZ NoDZ X a bc d NoX Compare your answers to Parts 1 and 3. X causes DZ. Detectives in the Classroom – Investigation 3-2: Cause

29. DZ NoDZ X a bc d NoX Cigarette smoking causes lung cancer. Have you identified cell a? Have you identified cells b and c? Have you identified cell d? Compare your answers to Parts 1 and 3. Detectives in the Classroom – Investigation 3-2: Cause

30. 5 Describe how you can have people in cells b and c and still put a label on a pack of cigarettes that reads “… smoking causes lung cancer ….” Cigarette smoking causes lung cancer. Have you mentioned time delay between exposure and outcome? Have you mentioned the possible need for another exposure? SURGEON GENERAL’S WARNING:Smoking Causes Lung Cancer, Heart Disease, Emphysema, and May Complicate Pregnancy Detectives in the Classroom – Investigation 3-2: Cause

31. 6 Label a 2 x 2 table and identify the cells in which there would be people if the exposure caused the disease. Lack of fitness and physical activity causes heart attacks. a bc d Detectives in the Classroom – Investigation 3-2: Cause

32. NoHeart Attack Heart Attack Lack of Fitness No Lack of Fitness 6 Lack of fitness and physical activity causes heart attacks. a b a bc d c d Label a 2 x 2 table and identify the cells in which there would be people, if the exposure caused the disease. Detectives in the Classroom – Investigation 3-2: Cause

33. Epi Talk Epi Talk Multiple Causes A combination of causes or an alternative cause that produces the effect. Detectives in the Classroom – Investigation 3-2: Cause

34. 7 Label a 2 x 2 table and identify the cells in which there would be people if the exposure caused the disease. Lack of supervision of small children causes lead poisoning. a bc d Detectives in the Classroom – Investigation 3-2: Cause

35. NoLead Poisoning Lead Poisoning Lack of Supervision No Lack of Supervision 7 Lack of supervision of small children causes lead poisoning. a b a bc d c d Label a 2 x 2 table and identify the cells in which there would be people if the exposure caused the disease. Detectives in the Classroom – Investigation 3-2: Cause

36. Explanations for Finding an Association 1. Cause 2. 3. 4. 5. Why would an exposure and an outcome turn up together? Detectives in the Classroom – Investigation 3-2: Cause

37. Investigation 3-2 has ended. CDC Cause Detectives in the Classroom – Investigation 3-2: Cause