@yudapearl @robertwplatt Suppose we are studying patients with severe aortic stenosis that are planning to undergo transcatheter aortic valve replacement.
@yudapearl @robertwplatt Suppose there are two different "approaches" that may be used for TAVR. We wish to know if one of them is better than the other.
@yudapearl @robertwplatt But, for various reasons (vascular anatomy, frailty, local operational preferences patient preference) not all patients are really proper "candidates" for both approaches.
Suppose I want to know if a particular medication is effective in preventing hospitalization of newly diagnosed COVID patients.
@ztownsend@rabois@MaartenvSmeden Suppose that there are 100,000 new cases in a given week, and by some miracle I have a rich data source that includes a) their date of positive test, b) whether they were hospitalized in the next 30 days after the test, and c) whether they received the medication for all 100K.
@ztownsend@rabois@MaartenvSmeden If that’s all detected cases from the population of interest, I have “census” here so I don’t need “sampling” to know “what’s the probability of being hospitalized?” - but can I confidently answer the question “was the medication effective at reducing hospitalization?”
Time for my annual love letter to @CritCareReviews and why you should consider going if combination of (location, dates, times, personal circumstances, and other considerations) permit
1. The format is like no other conference I've attended. Instead of 12 concurrent sessions , with a bunch of 10 minute talks that allow 1 question at the end, there's one main stage.
2. On that one main stage, we have the chance to go deep into each trial. Each gets a 90-minute block where the team gets 30-45 minutes to present a detailed history and motivation for the study, talk at length about their experience actually doing it, and of course the results.
Tongue-in-cheek post from @mikejohansenmd, but this is a pedantic point that increasingly bothers me when I see it: researchers wrongly identifying studies as "case-control" studies that are nothing of the sort.
@mikejohansenmd (It doesn't invalidate the work, really, it's just odd to see how many researchers don't seem to understand what a "case-control study" actually is)
@mikejohansenmd A case-control study *starts* with a group of "cases" - people who have the outcome of interest - and then identifies some suitable "controls" - people who are somehow similar to the "cases" but do not have the outcome of interest.