4 ms·

This is an interesting study, and I highly encourage everyone to also read the accompanying editorial, which raises some important methodological shortcomings.

by nkrumm 9y ago

This is an interesting study, and I highly encourage everyone to also read the accompanying editorial, which raises some important methodological shortcomings. See here: https://jamanetwork.com/journals/jama/fullarticle/2657356 https://jamanetwork.com/journals/jama/fullarticle/2657356 The reason this study was done because there has been a very well replicated association between the plasma (not red cells) donated from previously pregnant women and the risk of TRALI, a very rare but deadly transfusion reaction. After this association was made clear, blood banks no longer collect plasma from previously pregnant ("ever pregnant") women, and the overall rate of TRALI has dramatically dropped (from about 35 fatalities in the US per year to ~15). Source: MD/lab medicine resident

wnissen 9y ago
Do you have any insight into why, when they were looking at men vs. two types of women, 88% of the blood donors were men? Seems like you would want at least 50% women.
- salad77 9y ago
  I don't think an ethics committee would approve of exposing a study group to a known or suspected higher risk of death without significant safeguards. Using a small sample exposed to the suspected risk and the vast majority not exposed sounds like responsible ethics. It is not stated, but there should also have been additional safeguards and monitoring. It is normal for studies to be terminated early if they are found to expose participants to either too much danger or if the study group is found to be significantly advantaged (in which case, for example, the whole group is given the beneficial treatment instead of just the small study group). 50% may sound 'fair' or 'equal', but this is about researching ways of saving life, some social notion of fairness or gender equality is not relevant and, if this study is correct, could have caused excessive death. Is it worth people being killed to get the gender balance into the shape you prefer?
  - ThatGeoGuy 9y ago
    > Is it worth people being killed to get the gender balance into the shape you prefer? This is obviously a tough question to answer, and maybe the answer here is no. Further, I wouldn't say "worth people being killed" as much as I'd say it's "worth risking people dying". Obviously this is context sensitive and is different for each treatment and study. Despite this, as the devils advocate, you could say that given that men and women can respond to different treatments in a range of ways, the ideal distribution would be diverse enough to accommodate for those differences, which would provide a better statistical subset and by extension producing "better" data. Same caveats apply, where you mentioned "too much danger" and if the study is "significantly advantaged". In short, it could be less about fairness (equity) or equality and more about collecting a broader or more diverse range of data.
    - downrightmike 9y ago
      Correct answer is always no. No one should be knowingly killed or endangered to suit a biased view.
  - aladoc99 9y ago
    It seems as though people are getting the idea that this was a randomized trial, where people were assigned to receive units of blood from various types of donors. However, it was a retrospective case-control study, where records from everyday clinical practice were analyzed after the fact to look for patterns or, as in this case, try to answer questions. Did people who had received units of PRBCs from various types of donors fare any differently? I tend to view this kind of study as valuable for hypothesis generation, but not for solid conclusions, because it's impossible to control for every possible confounding factor. So the notion of ethics committees being concerned about patient's mortality doesn't apply here. All patients in the study have already either survived the study period or not. Same for safeguards, monitoring, and early termination.
- thatcat 9y ago
  Not OP, but have sold plasma before. The typical person selling plasma is at the bottom 1% of the income distribution, turns out there are a lot more homeless men than women so I would venture that it's an availability issue.
jxramos 9y ago
thanks for defining "ever pregnant", I thought this was some weird birthcontrol thing as in faking the body to thinking its already pregnant perpetually. "Ever pregnant" as in "has been pregnant at least once" or as you say "previously pregnant". Also for those who want to know https://en.wikipedia.org/wiki/Transfusion-related_acute_lung_injury https://en.wikipedia.org/wiki/Transfusion-related_acute_lung...
- thaumasiotes 9y ago
  Can I ask where you're from? I don't personally see a difficulty using "ever pregnant" to mean "has ever been pregnant".
  - jxramos 9y ago
    from the states, but I guess my thoughts landed on phrases like "ever more", which makes me wonder if that's actually two words... nope it's a single word: evermore. Looks like I was interpreting the word in its first definition, but it was meant in the 2a definition Definition of ever 1 :always; eg * ever striving to improve * the ever-increasing population 2a :at any time * more than ever before 2b :in any way * how can I ever thank you 3 —used as an intensive * looks ever so angry * am I ever happy to see you
    - thaumasiotes 9y ago
      Hmmm... I don't like definition 2b. I think senses (1) and (2a) as given here are both related to the core "ever" concept "encompassing all of time", and "how can I ever thank you" rhetorically emphasizes that no matter how long you spend trying, you'll never be able to thank the person properly.
      - jxramos 9y ago
        If one cannot exhaustively find a sufficient reply to give in thanks after so much time than I'd say that's logically identical to being unable to reply "in any way". the emphasis of the former is on the search and it's ultimate futility, the emphasis of the latter for the existence lacking in the first place which precludes any successful search.

by nkrumm 9y ago

wnissen 9y ago

Do you have any insight into why, when they were looking at men vs. two types of women, 88% of the blood donors were men? Seems like you would want at least 50% women.

salad77 9y ago
I don't think an ethics committee would approve of exposing a study group to a known or suspected higher risk of death without significant safeguards. Using a small sample exposed to the suspected risk and the vast majority not exposed sounds like responsible ethics. It is not stated, but there should also have been additional safeguards and monitoring. It is normal for studies to be terminated early if they are found to expose participants to either too much danger or if the study group is found to be significantly advantaged (in which case, for example, the whole group is given the beneficial treatment instead of just the small study group). 50% may sound 'fair' or 'equal', but this is about researching ways of saving life, some social notion of fairness or gender equality is not relevant and, if this study is correct, could have caused excessive death. Is it worth people being killed to get the gender balance into the shape you prefer?
- ThatGeoGuy 9y ago
  > Is it worth people being killed to get the gender balance into the shape you prefer? This is obviously a tough question to answer, and maybe the answer here is no. Further, I wouldn't say "worth people being killed" as much as I'd say it's "worth risking people dying". Obviously this is context sensitive and is different for each treatment and study. Despite this, as the devils advocate, you could say that given that men and women can respond to different treatments in a range of ways, the ideal distribution would be diverse enough to accommodate for those differences, which would provide a better statistical subset and by extension producing "better" data. Same caveats apply, where you mentioned "too much danger" and if the study is "significantly advantaged". In short, it could be less about fairness (equity) or equality and more about collecting a broader or more diverse range of data.
  - downrightmike 9y ago
    Correct answer is always no. No one should be knowingly killed or endangered to suit a biased view.
- aladoc99 9y ago
  It seems as though people are getting the idea that this was a randomized trial, where people were assigned to receive units of blood from various types of donors. However, it was a retrospective case-control study, where records from everyday clinical practice were analyzed after the fact to look for patterns or, as in this case, try to answer questions. Did people who had received units of PRBCs from various types of donors fare any differently? I tend to view this kind of study as valuable for hypothesis generation, but not for solid conclusions, because it's impossible to control for every possible confounding factor. So the notion of ethics committees being concerned about patient's mortality doesn't apply here. All patients in the study have already either survived the study period or not. Same for safeguards, monitoring, and early termination.
thatcat 9y ago
Not OP, but have sold plasma before. The typical person selling plasma is at the bottom 1% of the income distribution, turns out there are a lot more homeless men than women so I would venture that it's an availability issue.

jxramos 9y ago

thanks for defining "ever pregnant", I thought this was some weird birthcontrol thing as in faking the body to thinking its already pregnant perpetually. "Ever pregnant" as in "has been pregnant at least once" or as you say "previously pregnant". Also for those who want to know https://en.wikipedia.org/wiki/Transfusion-related_acute_lung_injury https://en.wikipedia.org/wiki/Transfusion-related_acute_lung...

thaumasiotes 9y ago
Can I ask where you're from? I don't personally see a difficulty using "ever pregnant" to mean "has ever been pregnant".
- jxramos 9y ago
  from the states, but I guess my thoughts landed on phrases like "ever more", which makes me wonder if that's actually two words... nope it's a single word: evermore. Looks like I was interpreting the word in its first definition, but it was meant in the 2a definition Definition of ever 1 :always; eg * ever striving to improve * the ever-increasing population 2a :at any time * more than ever before 2b :in any way * how can I ever thank you 3 —used as an intensive * looks ever so angry * am I ever happy to see you
  - thaumasiotes 9y ago
    Hmmm... I don't like definition 2b. I think senses (1) and (2a) as given here are both related to the core "ever" concept "encompassing all of time", and "how can I ever thank you" rhetorically emphasizes that no matter how long you spend trying, you'll never be able to thank the person properly.
    - jxramos 9y ago
      If one cannot exhaustively find a sufficient reply to give in thanks after so much time than I'd say that's logically identical to being unable to reply "in any way". the emphasis of the former is on the search and it's ultimate futility, the emphasis of the latter for the existence lacking in the first place which precludes any successful search.