# cigarette smoking vs. tanning - Severe flaw in statistics **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [April 19, 2009, 3:42pm UTC](https://boards.straightdope.com/t/cigarette-smoking-vs-tanning-severe-flaw-in-statistics/493624 "2009-04-19T15:42:31Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![cybrbeast](https://avatars.discourse-cdn.com/v4/letter/c/8baadc/32.png) [@cybrbeast](https://boards.straightdope.com/u/cybrbeast)\ **Post date:** [April 19, 2009, 3:42pm UTC](https://boards.straightdope.com/t/cigarette-smoking-vs-tanning-severe-flaw-in-statistics/493624/1 "2009-04-19T15:42:31Z")
Dear Cecil, in the article you mention the increases in cancer risk these behaviors cause. However one needs to know what the occurrence of the cancer in the general population is before one can conclude which behavior is more lethal. Example (with bogus numbers) if you double your risk of lung cancer and the prevalence of lung cancer in the population is 2 out of 1000, you have a chance of 4 in 1000 of getting lung cancer (an increase of 2 in 1000). If the prevalence of melanoma is 10 out of 1000 and you have a 50% higher chance of getting melanoma you have 15 out of 1000 chance of getting it (an increase of 5 in 1000). So you’d have a higher chance of melanoma than lung cancer. ---
**Author:** ![cybrbeast](https://avatars.discourse-cdn.com/v4/letter/c/8baadc/32.png) [@cybrbeast](https://boards.straightdope.com/u/cybrbeast)\ **Post date:** [April 19, 2009, 8:42pm UTC](https://boards.straightdope.com/t/cigarette-smoking-vs-tanning-severe-flaw-in-statistics/493624/2 "2009-04-19T20:42:26Z")
My apologies, I see that the issue was already mentioned here: > **[Meaningless numbers in smoking/tanning cancer comparison](https://boards.straightdope.com/sdmb/showthread.php?t=514435)** > > In this column, Cecil came to the following conclusion: This statement is completely worthless unless we’re given the base percentages in the first place. For instance, if he’s increasing his chance of getting cancer from 0.01% to 0.02%, while... ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [April 20, 2009, 9:44pm UTC](https://boards.straightdope.com/t/cigarette-smoking-vs-tanning-severe-flaw-in-statistics/493624/3 "2009-04-20T21:44:57Z")
“Don’t get all mathy on me.” --Pointy Haired Boss