how much of what we believe about endpoint actually comes from SELECT threads
how much of what we believe about endpoint actually comes from SELECT threads — that is what I am asking, and I have already read the wiki twice.
On means, which this board treats as targets and which are nothing of the sort.
A reported mean body weight change is the centre of a distribution that in these trials is very wide. Substantial numbers of participants did much better, and substantial numbers did considerably worse while remaining on the drug and in the analysis.
Quoting the mean as an expectation therefore misleads in both directions: it makes ordinary results look like failures and it makes exceptional results look normal. If a paper publishes the distribution — and several do, in the appendix — look at that instead. It is far more informative than the number in the abstract.
Intention-to-treat analyses everybody randomised regardless of what they did afterwards. Completer analyses only those who finished. The second is systematically more flattering and both are legitimate if labelled.
A confidence interval is the range of effects compatible with the data. Two trials with overlapping intervals have not disagreed, whatever their point estimates look like next to each other.
Sceptical readings welcome. The confident ones are the ones I distrust.
best — the order this archive was captured in
How to read one of these papers in fifteen minutes, in the order that actually helps.
Start with the registered protocol and check the primary endpoint against what is reported. Then the methods: who was included, what the comparator was, how long the randomised phase ran. Then the discontinuation numbers, which are a tolerability result and are usually in a supplementary table.
Only then the efficacy figure, and read the interval rather than the point estimate. Finish with the limitations section, which is where the authors say what they actually think.
Fifteen minutes, and you will know more than any thread summarising it.
Careful with that mean. The distribution around it was wide enough that it describes very few individual participants.
Read a press release and the publication three months apart. The hedging in the second one was substantial.
That is the 68-week readout, not the 72-week one. Different trial, different duration.
Argued for a week about a result and then read the limitations section, which conceded most of my opponent’s point.
Went looking for the registered protocol to see whether the endpoint had changed. It had not, which was reassuring and worth checking.
Added the trial identifier to the title so this thread is findable in two years.
Went looking for the registered protocol to see whether the endpoint had changed.
Adding the check nobody runs — the registered protocol is public and takes two minutes to compare.
This. Intention-to-treat versus completer analysis routinely moves the headline by several points.
phase 2 finds a dose, phase 3 measures the effect
Absolute or relative risk reduction?
SURPASS is the diabetes programme and reports glycaemic endpoints