May 3, 2021

Briefly

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  • Mediawatch took on bogus polls and interviewed me.
  • If you ask people whether the recent stories about blood clotting affect their views on Covid vaccines they will say ‘yes’. But if you asked people, before and after, what their views actually are, there’s a very slight change to be more pro-vaccine.
  • A study of 9806 blood donors found 8 had antibodies to the Covid virus.  Extrapolated crudely to all of NZ that’s about 4000 undiagnosed cases. I’m not giving a statistical uncertainty interval because the non-sampling uncertainty is going to be larger — blood donors tend to be younger and so more likely to have been asymptomatic/weakly symptomatic and thus not tested, but might also be less likely to have been infected.  Still, the number is in the sort of range you’d expect.
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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar
    Megan Pledger

    The 8 cases were from 7 DHBs. That just sounds a bit odd. That doesn’t really follow the distribution of where the cases were (although small numbers).

    3 years ago

  • avatar
    Steve Curtis

    For the ‘blood clots’, the head of the Australian equivalent to Medsafe, Professor Skerritt said
    ‘We also have to remember that in reporting cases of people presenting in hospitals with clots or to their GP, 50 Australians each day report to hospitals with serious blood clots.’
    https://www1.racgp.org.au/newsgp/clinical/no-evidence-that-recent-blood-clot-deaths-were-lin
    Even if they get ‘one a week’ after a vaccination, its barely perceptible against the normal situation

    3 years ago

    • avatar
      Thomas Lumley

      It’s completely imperceptible if you lump them in with all other blood clots — we know about these ones because they are so different from the more common cases in location and biochemistry and treatment, as well as in cause.

      3 years ago