Source for the substitution between formats figure, since it was asked for. It is in the discussion rather than the abstract, which is why the version circulating is stronger than the paper is. Reading the surrounding paragraph is worth the two minutes. The authors are more careful than their summarisers.
On the subject in the title: Substitution between formats during a shortage Working notes rather than a conclusion.
The question about substitution between formats that I actually want answered is the second one below. The first is context and I have kept it short.
Both are stated with units, and I have said what I already checked so that nobody repeats it.
Source for the substitution between formats figure, since it was asked for. It is in the discussion rather than the abstract, which is why the version circulating is stronger than the paper is.
Reading the surrounding paragraph is worth the two minutes. The authors are more careful than their summarisers.
Adding the measurement that post #2 says would settle it.
Two claims get bundled together under substitution between formats and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.
Almost every disagreement in threads like this one dissolves once you say which of the two you are making.
Same experience here, different supplier, so it is at least not unique to one of them.
Shortage status determines what compounding is permitted in some jurisdictions, which links two questions that otherwise seem unrelated.
Switching presentation or strength during a shortage is a prescribing decision rather than a substitution anybody should improvise.
Shortage predictions: regulators and suppliers issue shortage alerts before they become acute. Checking the regulatory website for shortages gives you advance notice.
That is my reading. Someone else read the same page differently and was reasonable.
Stockpiling in response to a shortage worsens it, which is true and is a poor argument to make to somebody who has run out.
I would call that likely rather than established.
Worth separating two things that post #11 runs together.
The practical version of substitution between formats is three sentences long. The rigorous version is three pages and reaches the same conclusion with the conditions attached.
This follows post #11 rather than contradicting it.
Regional differences during a shortage are large, and a supply position in one country says nothing about another.
Nothing here is medical advice, and decisions about what to do during a supply interruption belong with a prescriber.
For what it is worth, the same held on the two occasions I checked.
That is consistent with mine, for whatever one more account is worth.
The published shortage register maintained by the national regulator is the authoritative source here, and it is updated far more often than any thread.
I had written a reply contradicting post #15 and deleted it. Here is what survived.
The thing about substitution between formats that took me longest to accept is that a plausible mechanism is not evidence of an effect. It is a reason to look, not a result.
Confirming post #19 from a second method, which matters more than confirming it from a second person.
What I want from this substitution between formats 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.
Planning around a known shortage window is easier than reacting to one, and the notices give advance warning more often than people expect.
Pharmacy-level availability varies enormously during a shortage, so two honest accounts from the same city can be opposite.
The interesting part of this is the exception, and I do not understand the exception.
Seconded. It reads as careful rather than confident, which is the right register.
Small methodological point on substitution between formats: repeating a measurement is cheap and resolves most of what is being argued about here at no cost to anyone.
Trying to state the substitution between formats position in a way that someone who disagrees would recognise as fair, because I do not think the version in this thread passes that test.
Anyone reporting availability should say the region and the date, because both determine whether the report is usable.
Post #26 and I disagree about the size of the effect, not about the direction.
Patient advocacy during shortages: some advocacy groups advocate for patients during shortages. Knowing who they are and following their communication is useful.
Small point, but it is the one that usually catches people.
The arithmetic in post #28 is right; the assumption feeding it is the part to check.
The strongest argument against my own position on substitution between formats, stated as well as I can state it, since nobody else has yet.
Answering the question post #26 raises rather than the one it answers.
Manufacturer allocation decisions during a shortage are commercial and are rarely explained, which is frustrating and is not evidence of anything.
I have changed my mind on this once already, so take it as current rather than settled.