Numbers Need Context!

Transcript

1. Context Numbers need
2. Although not everyone might agree, Statistics are…
3. Although not everyone might agree, Statistics are… Interesting
4. Although not everyone might agree, Statistics are… Interesting Educational
5. Although not everyone might agree, Statistics are… Interesting Educational Important
6. But it can often be hard to understand them without CONTEXT
7. Our media abounds with context-less numbers
8. Let’s take a look at a few…
9. “Bacon increases risk of colorectal cancer by 20%”
10. “Bacon increases risk of colorectal cancer by 20%” “1 extra unit of alcohol a day increases a woman’s risk of breast cancer by 12%”
11. “Bacon increases risk of colorectal cancer by 20%” “1 extra unit of alcohol a day increases a woman’s risk of breast cancer by 12%” “Just 2 units of alcohol a day reduces risk of heart disease by 17%”
12. But what do the percentages really mean in real life?
13. And is there a more relevant way we could be describing this information
14. “Bacon increases risk of Colorectal cancer by 20%”
15. But just how bad is that?
16. Lets assume that ordinarily 5 out of 100 people develop Colorectal cancer.
17. Therefore if all 100 ate 3 extra rashers every day... The number could rise to six
18. Therefore if all 100 ate 3 extra rashers every day... The number could rise to six
19. So therefore…
20. So therefore… Bacon increases risk of Colorectal cancer by 20%
21. So therefore… Bacon increases risk of Colorectal cancer by 20% Is the exact same as saying
22. So therefore… Bacon increases risk of Colorectal cancer by 20% Is the exact same as saying About 1 extra case per 100 people
23. Next up…
24. “One extra unit of alcohol a day increases a woman's risk of breast cancer by 12%”
25. But just how bad is that?
26. Let’s assume about 10 out of 100 women have breast cancer in a lifetime
27. If all 100 drink an extra unit a day, that number rises to 11.
28. If all 100 drink an extra unit a day, that number rises to 11.
29. So therefore…
30. So therefore… One extra unit of alcohol a day increases a woman's risk of breast cancer by 12%”
31. So therefore… One extra unit of alcohol a day increases a woman's risk of breast cancer by 12%” Is the exact same as saying
32. So therefore… One extra unit of alcohol a day increases a woman's risk of breast cancer by 12%” Is the exact same as saying About 1 extra case per 100 people
33. And Finally…
34. “Just two units a day reduces risk of heart disease by 17%”
35. But just how GOOD is that?
36. About 32 out of 100 women have coronary heart disease in a lifetime.
37. If all 100 were to drink 2 units of alcohol every day… that number would fall to 27
38. If all 100 were to drink 2 units of alcohol every day… that number would fall to 27
39. So therefore…
40. So therefore… Just two units a day reduces risk of heart disease by 17%
41. So therefore… Just two units a day reduces risk of heart disease by 17% Is the exact same as saying
42. So therefore… Just two units a day reduces risk of heart disease by 17% Is the exact same as saying About 5 fewer cases per 100 people
43. So we have a little problem
44. Depending on the story
45. 20% can equal 1 person in 100
46. 20% can equal 1 person in 100 12% can equal 1 person in 100
47. 20% can equal 1 person in 100 12% can equal 1 person in 100 17% can equal 5 people in 100
48. So…
49. Percentage figures without CONTEXT are meaningless and can often misleading
50. When talking about health matters it isn’t enough to deal with percentages
51. Think about number of lives affected
52. And…
53. We must hold our media to account and ensure that journalists do not go for the FLASHY, SHINY and TRENDY (not to mention misleading) sounding story rather than the more relevant and helpful one...
54. Because…
55. Those… “Who might rely on the news for guidance, deserve something more relevant” (M. Blastland)
56. You can find me at: www.clearpreso.com www.twitter.com/clearpreso