Tim Morris's Avatar

Tim Morris

@timpmorris.bsky.social

Biostatistician working on methodology at Novartis. Simulation studies, non-inferiority, missing data, estimands, covariate adjustment… He/him https://tpmorris.substack.com/

2,350 Followers  |  455 Following  |  1,441 Posts  |  Joined: 20.09.2023  |  1.8866

Latest posts by timpmorris.bsky.social on Bluesky

Two slices of gluten-free bread with large air pocket at the bottom making the shape of an intensely sad mouth

Two slices of gluten-free bread with large air pocket at the bottom making the shape of an intensely sad mouth

Classic bit of pathetic fallacy here from my gluten-free bread

10.10.2025 08:42 — 👍 2    🔁 0    💬 0    📌 0

Talk to us, what font is it?

09.10.2025 21:12 — 👍 3    🔁 0    💬 2    📌 0

Hey, imagine how tough life must be striking the right balance between being top-2% and not-suspiciously-prolific, plus staying productive while people waste your time patiently explaining how you’re wrong!

09.10.2025 19:44 — 👍 3    🔁 0    💬 0    📌 0

I’m thinking about the methods research that tends to get funded. Precious little late-phase methodology (often viewed as insufficiently novel etc.).

09.10.2025 15:46 — 👍 1    🔁 0    💬 1    📌 0

I reckon not much – so many of the problems in funded applied research are so basic and obvious that any fundable methods research would be too sophisticated!

09.10.2025 15:11 — 👍 1    🔁 0    💬 1    📌 0
Post image

New (short) post on hearing criticism of your work.

No, I’m not telling you who it was – they will recognise themself!

open.substack.com/pub/tpmorris...

08.10.2025 16:17 — 👍 1    🔁 0    💬 0    📌 0

My favorite genre of fiction is Thesis Acknowledgments.

02.05.2025 10:39 — 👍 46    🔁 6    💬 2    📌 0

Straight onto my reading list

24.09.2025 05:21 — 👍 1    🔁 0    💬 0    📌 0
The morning sun peeping around some horse chestnuts (non-native) and hornbeams (non-native)

The morning sun peeping around some horse chestnuts (non-native) and hornbeams (non-native)

The defenders of British Values, having completed their work assaulting police officers, have returned home, leaving London a Dystopian Hellscape once again

15.09.2025 08:33 — 👍 10    🔁 0    💬 0    📌 0

Bonus marks for explaining why the quoted post appears to be wrong but the quoting post is in fact wrong.

15.09.2025 08:29 — 👍 2    🔁 0    💬 0    📌 0

Why does everyone who picks up the mic at this conference feel they have to mention this talk, whether grudgingly or positively??

11.09.2025 15:11 — 👍 3    🔁 0    💬 0    📌 0

Hahaha I enjoyed that! Yes, I agree on the sentence/s (these documents do not cite any references though, which always annoys people).

11.09.2025 11:39 — 👍 2    🔁 0    💬 0    📌 0

Very much agree with that last point. I think what you’re politely saying translates to “come back when you’ve read my 🤬 paper!”

11.09.2025 11:36 — 👍 2    🔁 0    💬 1    📌 0

The second sentence of your abstract!

11.09.2025 10:50 — 👍 0    🔁 0    💬 1    📌 0

Isn’t this like complaining that the bus to the airport fell short when it didn’t fly you to your destination? 😜

It’s gives us a useful (important) start but is not a grand-unifiying-all-singing-all-dancing solution!

11.09.2025 10:47 — 👍 0    🔁 0    💬 1    📌 0
Post image

😜

11.09.2025 09:17 — 👍 2    🔁 0    💬 1    📌 0
Post image

I’m just a bit baffled about what you think this is “inferior to”. Writing an subsequent expression in terms of potential outcomes? If so, this should come from the natural-language version, not compete with it.
E.g. doi.org/10.1002/sim....

11.09.2025 08:46 — 👍 0    🔁 0    💬 1    📌 0

Inferior to what? For the Addendum, the whole point is to give a structured description of the estimand in natural-language.

This should *not* set the estimand in stone – we cannot just skip past identification, estimation, implementation &c. – though practice isn’t as good as the intention.

11.09.2025 08:46 — 👍 0    🔁 0    💬 1    📌 0

Yes, thanks. I disagree with your premise too as I disagree with Hernán’s grift: being able to say what trial you would like to do does not say what the estimand is, it’s something like “the estimand would be identified under this design”. But a causal estimand does not depend on study design!

11.09.2025 08:20 — 👍 2    🔁 0    💬 1    📌 0

Definitely. I guess lots of useful approaches gain this problem once popular (estimands for one). A superficial label accompanied by no-thinking.

10.09.2025 15:41 — 👍 1    🔁 0    💬 1    📌 0

Yes, agree!

10.09.2025 15:18 — 👍 0    🔁 0    💬 1    📌 0
Screenshot of a slide.
Title: “Addendum contributions (‘IMO’)”
Left hand column says
“Five ‘attributes’
1. Treatment condition of interest
2. Target population
3. Outcome variable
4. Intercurrent events
5. Population-level summary
measure”
Right hand column says
“Handling intercurrent events (LHS point 4)
1. ‘Treatment policy’
2. ‘Hypothetical’
3. ‘Composite variable’
4. ‘While on treatment’
5. Principal stratum”

Screenshot of a slide. Title: “Addendum contributions (‘IMO’)” Left hand column says “Five ‘attributes’ 1. Treatment condition of interest 2. Target population 3. Outcome variable 4. Intercurrent events 5. Population-level summary measure” Right hand column says “Handling intercurrent events (LHS point 4) 1. ‘Treatment policy’ 2. ‘Hypothetical’ 3. ‘Composite variable’ 4. ‘While on treatment’ 5. Principal stratum”

Thanks Cameron!
Dean, two key points:
1. It’s the structure in this pic that we all find so useful.
2. The “Intercurrent event strategies” mean interplay with the other four attributes.

10.09.2025 14:15 — 👍 8    🔁 2    💬 1    📌 0

One more. In comparing “Trials” & “Target trials”, slide says something like “causal contrasts” vs. “observational analogs of contrasts”. Causal contrasts are of potential outcome distributions (see Hernán & Robins’ book), which do not depend on the study design – no “observational analog”!

10.09.2025 14:00 — 👍 3    🔁 0    💬 0    📌 0

The target trials concept is great; I’m not slamming that. But even the poster-child examples leave a lot ambiguous (partly because they seem to rely on readers being able to reverse-engineer estimands).

10.09.2025 13:52 — 👍 6    🔁 0    💬 1    📌 0

I’d say substance was largely absent. Most gripes were about minor semantic things. Seemed like sour grapes that the trials community didn’t think “real trials have target trials too” solved everything for them, and he wants them to turn back from this 🤷

10.09.2025 13:50 — 👍 3    🔁 0    💬 1    📌 0

Having to infer the estimand from the design + analysis was one of the things that led to the E9(R1) addendum in the first place!
Also that the “ITT effect [sic] is never relevant” thing, avoiding engaging with how you would realise a different intercurrent event strategy in practice.

10.09.2025 13:38 — 👍 4    🔁 0    💬 1    📌 0

I’ve heard about this second-hand but assumed it was a caricature.
He is claiming that describing a target trial protocol makes the estimand crystal clear, so there is no need for anything else. But if we actually did the target trial, we would have to infer the estimand from design + analysis!

10.09.2025 13:38 — 👍 5    🔁 0    💬 1    📌 0

Miguel Hernán is presenting at EFSPI and giving a frankly embarrassing rant about (addendum-style) estimands. While lots of people are constructively using it to complement causal inference, he is sticking to basic & straw-man gripes that are easily addressed by thinking or listening to others.

10.09.2025 13:29 — 👍 16    🔁 1    💬 4    📌 1

That’s it. I can see that power dynamics are a problem, and that’s probably why there’s a reluctance to challenge anything from PPI colleagues, but no challenge makes the whole activity… inauthentic, right?

05.09.2025 15:04 — 👍 1    🔁 0    💬 0    📌 0

Sorry to pick on this one sentence. I just thought the question “is it allowed to be negative about PPI” was a very interesting one.
3/

05.09.2025 10:53 — 👍 0    🔁 0    💬 1    📌 0

@timpmorris is following 20 prominent accounts