Journal club: LEADER as the historical anchor Writing it up because I had to work it out twice and would rather nobody else did.
What changes if the standard account of LEADER is wrong? I ask because I have been treating it as settled and I noticed this week that I could not say why.
Working through the consequences rather than the evidence, since others here are better placed on the evidence.
Where the group cannot agree, record the disagreement rather than resolving it by seniority. The recorded disagreement is more honest and more useful later.
The opening post answers the question as asked. The question underneath it is different.
The baseline characteristics table is the single most useful page for the questions that get asked here, because it tells you who the result applies to.
It took me longer than it should have to see that.
The number people quote for LEADER is a central estimate presented without its interval, and the interval is wide enough that the estimate is nearly uninformative on its own.
Agreed, and I will stop repeating the version of this I had been repeating.
Narrowing post #5, because the general version has more than one answer.
The most common failure mode is spending fifty minutes on the effect size and ten on the population. Reversing that ratio would improve most sessions.
Two people can read the same figure differently here and both be reasonable.
A definition problem is doing most of the work in this LEADER discussion. Once the term is pinned down I suspect the disagreement mostly goes away and what is left is small.
Picking up post #9: that is the part I would want checked first.
I would be cautious about generalising from the LEADER example above. It is a good example. It is one example.
Reading this LEADER thread as someone who came in with a fixed view: the third and seventh replies moved me and the confident ones did not.
Sessions on negative or null results are consistently the most instructive and the hardest to get anyone to attend.
I keep a log of this specifically because memory is unreliable about it.
Reading order that works for these sessions: registry entry, methods, baseline table, primary result, then abstract last. Reading the abstract first anchors everything that follows.
I have seen it go both ways, which is why I hedge.
On post #12 — agreed on the reasoning, with one qualification.
Practical experience of LEADER, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.
Bookmarking this. I will come back when I have something worth adding.
What I would check first on LEADER is whether the thing being measured moved or whether the way of measuring it moved. Those look identical in a graph.
I have been on both sides of the LEADER argument in this category within eighteen months, which should tell you how strong the evidence for either side is.
Where I part company with post #18, and it is a narrow parting.
Careful with the language on LEADER. "Not detected" and "not present" are different findings and the first is a statement about the method.
The baseline characteristics table is the single most useful page for the questions that get asked here, because it tells you who the result applies to.
Two questions I would want answered before drawing anything from the LEADER data above: how were the cases selected, and what happened to the ones that dropped out.
What I want from this LEADER thread is the list of things that would need to be true for the claim to hold. If we can write that list, we can check it.
Where the group cannot agree, record the disagreement rather than resolving it by seniority. The recorded disagreement is more honest and more useful later.
A single observation, in a thread that deserves better than single observations.
One caution on LEADER: everything above assumes the underlying documentation is what it claims to be. That assumption is doing real work and is rarely stated.
The figures usually contain the finding and the text usually contains the interpretation. Separating them for the first twenty minutes is a discipline worth keeping.
That has held every time I have looked, which is not the same as always.