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Compared to What?

Compared to What?. Compared to What?. Detectives in the Classroom - Investigation 2-2: Compared to What?. Hyphoteses. 2 Is there an association?. 1 How is this disease distributed?. Did the exposure and the disease turn up together?. 3 Is the association causal?. 4

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Compared to What?

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  1. Compared to What? Compared to What? Detectives in the Classroom - Investigation 2-2: Compared to What?

  2. Hyphoteses 2 Is there an association? 1 How is this disease distributed? Did the exposure and the disease turn up together? 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? Detectives in the Classroom - Investigation 2-2: Compared to What? Detectives en la clase — Investigación 2-1: La tabla 2x2 Detectives in the Classroom - Investigation 2-1: The 2x2 Table

  3. Review Trial 1 No Acne Acne Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 Explain what the 10% risk of acne tells you about the hypothesis “AcneMed prevents acne.” Detectives in the Classroom - Investigation 2-2: Compared to What?

  4. Review Epi Talk Control Group People who participate in a trial, but do not get the treatment. People whose results are compared to the group that was treated. Detectives in the Classroom - Investigation 2-2: Compared to What?

  5. Sample No AcneMed 100 teenagers Review Population Sample AcneMed 100 teenagers 10/100 or 10% All Teenagers Not Observed Not Observed ? / 100 or ? % Observed Detectives in the Classroom - Investigation 2-2: Compared to What?

  6. Review Identify the cell or cells in 2x2 table in which the following people belong: No Disease Disease Total Exposed a b c c d d Not Exposed People who are not exposed Detectives in the Classroom - Investigation 2-2: Compared to What?

  7. Review Identify the cell or cells in 2x2 table in which the following people belong: No Disease Disease Total b Exposed a b c d Not Exposed People who are exposed and do not have the disease Detectives in the Classroom - Investigation 2-2: Compared to What?

  8. Review Identify the cell or cells in 2x2 table in which the following people belong: No Disease Disease Total a Exposed a b c d Not Exposed People who are exposed and have the disease Detectives in the Classroom - Investigation 2-2: Compared to What?

  9. 10 10 % 10 90 or 100 Risks Trial 2 No Acne Acne Risk Acne Total AcneMed 100 a b c d No AcneMed 100 Detectives in the Classroom - Investigation 2-2: Compared to What?

  10. Epi Log Worksheet Detectives in the Classroom - Investigation 2-2: Compared to What?

  11. How would you describe the two risks? 10 10 % 10 90 or 100 10 10 90 % 10 or 100 1 Risks Trial 2 No Acne Acne Risk Acne Total AcneMed 100 a b c d No AcneMed 100 Detectives in the Classroom - Investigation 2-2: Compared to What?

  12. Review Epi Talk Risk A measure of how often an event occurs in a defined group of people in a defined period of time. The likelihood of developing a disease. Detectives in the Classroom - Investigation 2-2: Compared to What?

  13. Epi Talk Epi Talk Relative Risk A way of showing the relationship between two risks. Tells us the number of times one risk is larger or smaller than another. Calculated by dividing the risk of an outcome in one group by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  14. Relative Risk 10 10 % 10 90 or 100 10 10 90 % 10 or 100 2 Relative Risk Trial 2 No Acne Acne Risks Acne Total AcneMed 100 a b c d = 1 No AcneMed 100 Relative Risk: Risk of an outcome in one group divided by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  15. Review Epi Talk Relative Risk A way of showing the relationship between two risks. Tells us the number of times one risk is larger or smaller than another. Calculated by dividing the risk of an outcome in one group by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  16. Review Epi Talk Inference Process of predicting from what is observed in a sample to what is not observed in a population. To generalize back to the source population. Detectives in the Classroom - Investigation 2-2: Compared to What?

  17. Sample No AcneMed 100 teenagers Review Population Inference Sample AcneMed 100 teenagers 10/100 or 10% All Teenagers Not Observed 10 / 100 or 10 % Observed Detectives in the Classroom - Investigation 2-2: Compared to What?

  18. 10 10 % 10 90 or 100 10 10 90 % 10 or 100 3 Inference Trial 2 No Acne Acne Risk Relative Risk Acne Total AcneMed 100 a b c d = 1 No AcneMed 100 AcneMed is not associated with acne. AcneMed prevents acne. Detectives in the Classroom - Investigation 2-2: Compared to What?

  19. 4 Relative Risk Trial 3 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d 1 No AcneMed 1 99 100 or 1 % 100 Detectives in the Classroom - Investigation 2-2: Compared to What?

  20. Review Epi Talk Relative Risk A way of showing the relationship between two risks. Tells us the number of times one risk is larger or smaller than another. Calculated by dividing the risk of an outcome in one group by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  21. 4 5 Relative Risk Trial 3 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d = 10 1 No AcneMed 1 99 100 or 1 % 100 Relative Risk: Risk of an outcome in one group divided by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  22. 10 ! 6 Relative Risk Trial 3 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d = 10 1 No AcneMed 1 99 100 or 1 % 100 The teenagers who took AcneMed were ___ times as likely to develop acne as those who did not take AcneMed. Detectives in the Classroom - Investigation 2-2: Compared to What?

  23. 7 Inference Trial 3 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d = 10 1 No AcneMed 1 99 100 or 1 % 100 AcneMed does not prevent acne. AcneMed may cause acne! AcneMed prevents acne. Detectives in the Classroom - Investigation 2-2: Compared to What?

  24. 8 Relative Risk Trial 4 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d 40 No AcneMed 40 60 100 or 40 % 100 Detectives in the Classroom - Investigation 2-2: Compared to What?

  25. Review Epi Talk Relative Risk A way of showing the relationship between two risks. Tells us the number of times one risk is larger or smaller than another. Calculated by dividing the risk of an outcome in one group by the risk of an outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  26. 9 Relative Risk Trial 4 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d = 0.25 40 No AcneMed 40 60 100 or 40 % 100 Relative Risk: Risk of an outcome in one group divided by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  27. 9 Relative Risk Trial 4 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d = 0.25 40 No AcneMed 40 60 100 or 40 % 100 Relative Risk: Risk of an outcome in one group divided by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  28. 10 Relative Risk Trial 4 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d = 0.25 40 No AcneMed 40 60 100 or 40 % 100 0.25 The teenagers who took AcneMed were _____ times as likely to develop acne as those who did not take AcneMed. Detectives in the Classroom - Investigation 2-2: Compared to What?

  29. 11 Inference Trial 4 No Acne Acne Risk Relative Risk Acne Total 10 10 % AcneMed 10 90 100 or 100 a b c d = 0.25 40 No AcneMed 40 60 100 or 40 % 100 AcneMed prevents acne. AcneMed prevents acne. Detectives in the Classroom - Investigation 2-2: Compared to What?

  30. Relative Risk Relative Risk Type of Association Possible Interpretation 1 None The exposure is not associated with the outcome. Greater than 1 (>1) Positive The exposure is associated with an increase in the outcome. Less than 1 (<1) Negative The exposure is associated with a decrease in the outcome Relative Risk: Risk of an outcome in one group divided by the risk of the outcome in another group. Detectives in the Classroom - Investigation 2-2: Compared to What?

  31. “AcneMed Prevents Acne.” Trial 1 No Acne Acne Risk Acne Total 10 AcneMed 10 10 90 90 100 or 10% 100 a b c d Nothing 10 90 What do the results of Trial 1 tell us about the hypothesis “AcneMed prevents acne”? Detectives in the Classroom - Investigation 2-2: Compared to What?

  32. Trial 1 Trial 2 Trial 3 Trial 4 “AcneMed Prevents Acne.” Detectives in the Classroom - Investigation 2-2: Compared to What?

  33. 10 100 10 90 10% or 100 “AcneMed Prevents Acne.” Trial 1 No Acne Acne Risks Trial 2 Acne Total Acne Med Trial 3 Trial 4 Detectives in the Classroom - Investigation 2-2: Compared to What?

  34. 10 10 10 10 100 10 10 10 10 90 90 90 90 100 100 100 10% 10% 10% 10% 90 90 90 or or or or 100 100 100 100 “AcneMed Prevents Acne.” Trial 1 No Acne Acne Risk Trial 2 No Acne Acne Risks Acne Total Acne Total Acne Med Acne Med a b No Acne Med c d No Acne Acne Risks No Acne Acne Risks Trial 3 Trial 4 Acne Total Acne Total Acne Med Acne Med a a b b No Acne Med c d No Acne Med c d Detectives in the Classroom - Investigation 2-2: Compared to What?

  35. 10 10 10 10 100 10 10 10 10 90 90 90 90 100 100 100 10% 10% 10% 10% or or or or 100 100 100 100 40 1 10 1% 40% 10% or or or 10 40 1 60 90 99 100 100 100 100 100 100 “AcneMed Prevents Acne.” Trial 1 No Acne Acne Risk Trial 2 No Acne Acne Risks Acne Total Acne Total Acne Med Acne Med a b No Acne Med c d No Acne Acne Risks No Acne Acne Risks Trial 3 Trial 4 Acne Total Acne Total Acne Med Acne Med a a b b No Acne Med c d No Acne Med c d Detectives in the Classroom - Investigation 2-2: Compared to What?

  36. 10 10 10 10 100 10 10 10 10 90 90 90 90 100 100 100 10% 10% 10% 10% or or or or 100 100 100 100 40 1 10 40% 10% 1% or or or 1 40 10 60 90 99 100 100 100 100 100 100 Relative Risk Relative Risk Relative Risk “AcneMed Prevents Acne.” Trial 1 No Acne Acne Risk Trial 2 No Acne Acne Risks Acne Total Acne Total Acne Med Acne Med a b No Acne Med c d No Acne Acne Risks No Acne Acne Risks Trial 3 Trial 4 Acne Total Acne Total Acne Med Acne Med a a b b No Acne Med c d No Acne Med c d Detectives in the Classroom - Investigation 2-2: Compared to What?

  37. 10 10 10 10 100 10 10 10 10 90 90 90 90 100 100 100 10% 10% 10% 10% or or or or 100 100 100 100 40 10 1 10% 1% 40% or or or 1 10 40 60 99 90 100 100 100 100 100 100 1 Relative Risk 10 X as likely 0.25 X as likely Relative Risk Relative Risk “AcneMed Prevents Acne.” Trial 1 No Acne Acne Risk Trial 2 No Acne Acne Risks Acne Total Acne Total Acne Med Acne Med a b No Acne Med c d AcneMed is not associated with acne. No Acne Acne Risks No Acne Acne Risks Trial 3 Trial 4 Acne Total Acne Total Acne Med Acne Med a a b b No Acne Med c d No Acne Med c d AcneMed may cause acne! AcneMed prevents acne. Detectives in the Classroom - Investigation 2-2: Compared to What?

  38. 10 10 10 10 100 10 10 10 10 90 90 90 90 100 100 100 10% 10% 10% 10% 90 90 90 or or or or 100 100 100 100 “AcneMed Prevents Acne.” Trial 1 No Acne Acne Risk Trial 2 No Acne Acne Risks Acne Total Acne Total Acne Med Acne Med a Nothing b No Acne Med c d What do the results of Trial 1 tell us about the hypothesis: AcneMed prevents acne? Compared to What? No Acne Acne Risks No Acne Acne Risks Trial 3 Trial 4 Acne Total Acne Total Acne Med Acne Med a a b b No Acne Med c d No Acne Med c d Detectives in the Classroom - Investigation 2-2: Compared to What?

  39. Count Divide Compare CDC Detectives in the Classroom - Investigation 2-2: Compared to What?

  40. CDC No Acne Acne Risks Relative Risk Acne Total 10 10 % AcneMed 10 10 90 90 100 100 0.25 times as likely a b c d No AcneMed 40 10 40 60 90 100 40 % 100 Compare Divide Count Detectives in the Classroom - Investigation 2-2: Compared to What?

  41. Investigation 2-2 has ended. CDC Compared To What? Detectives in the Classroom - Investigation 2-2: Compared to What?

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