Re:Reduced cancer mortality with daily Vitamin D intake
by mholm on Tuesday May 09, 2023 @12:14PM
(#35876555)
That's what's confusing me: 105,000 participants in a study should have resulted in thousands of cancer deaths, a 12% drop should be pretty noticeable even with 10% of the data.
[ Parent
| on HN ]
Re:Reduced cancer mortality with daily Vitamin D intake
by kelseyfrog on Tuesday May 09, 2023 @12:24PM
(#35876713)
How exactly are you getting "should have resulted in thousands of cancer deaths"?
A population of 100,000 should expect to see 144.1 deaths[1].
If you evenly divide the study group into two 52,500-sized groups(treatment + control), each group should expect to see 72 deaths. A 12% drop in one of the groups is 8.6 deaths. As a colleague would say, that's very few clams from which to make a chowder.
Perhaps the researchers are using more advanced tools than I am, but even assuming a 12% difference between treatment and control does not result in a chi-squared test with any reasonable significance. ie: the null-hypothesis(there is no difference between groups) cannot be rejected.
1. https://www.cdc.gov/cancer/dcpc/research/update-on-cancer-de...
Re:Reduced cancer mortality with daily Vitamin D intake
by mholm on Tuesday May 09, 2023 @01:37PM
(#35877768)
144.1 deaths per year. Presumably these studies lasted multiple years. Though I'll admit this was less than I expected, which would explain the differing results.
Re:Reduced cancer mortality with daily Vitamin D intake
by kelseyfrog on Tuesday May 09, 2023 @01:51PM
(#35877963)
Thank you! Yes, the time frame is important, d'uh lol.