3 ms·
> “The research was based on the medical records of more than 46,000 women aged 35 to 74 from the Sister Study, meaning all women involved had a close relative
by velcrovan 7y ago
> “The research was based on the medical records of more than 46,000 women aged 35 to 74 from the Sister Study, meaning all women involved had a close relative who had died of breast cancer.”
Can someone explain to me how this isn’t a huge problem for this study?
- draw_down 7y agoCan you explain? If they all came from that set, and the ones who used straighteners/dyes developed cancer more often than the ones who didn't... what exactly am I missing here?
- natalyarostova 7y agoIt means they researchers hypothesized that the cost of generalizing to the population was less than the benefit from increased statistical power.
- UnFleshedOne 7y agoIf you want to be careful, you can say the study found that among cohort with increased cancer risk due to genetics, using those hair products increased cancer risk even further.
- tinco 7y agoCan you explain why it would be?
- btilly 7y agoYou go with the data that you have, not the data you wish you could get. It would be nice to redo the study with a large population that is randomly selected. However there is also no reason to believe that the results will be significantly different in direction. Therefore it would also be unwise to discount this result.
- jcutrell 7y agoDepends on the goal. If the risk factor is homogenized, then the variable researched can be isolated theoretically. However, this doesn’t allow you to test for interaction between those variables. In the study for example, they identify an apparent interaction between ethnicity and the chemicals mentioned; we don’t know what the effect size would be (whether additive, multiplicative, or something else entirely). (This is without any domain knowledge of the mechanisms of breast cancer to be fair.)