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Posts by David Laursen

Studies concerned complementary and alternative medical treatments, but mechanisms of bias though e.g. expectation likely similar in psychology?

5 days ago 0 0 0 0
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Bias due to lack of patient blinding in clinical trials. A systematic review of trials randomizing patients to blind and nonblind sub-studies Background: Blinding patients in clinical trials is a key methodological procedure, but the expected degree of bias due to nonblinded patients on estimated treatment effects is unknown. Methods: Syste...

Perhaps somewhat related: a systematic review looking at trials with both blinded and non-blinded patients:
pmc.ncbi.nlm.nih.gov/articles/PMC...

(Disclosure: the first author is my boss and supervisor)

5 days ago 2 0 1 1

Yes, typically. The classic example is atropine for imitating the anticholinergic effects of tricyclic antidepressants, e.g. dry mouth.

2 weeks ago 1 0 1 0

Yes, interesting that unblinding has not received more attention in the grand scheme of blinding. Although admittedly there have been sporadic discussions since the 1950s.

Unsure if active placebo controls may protect, but probably not always.

2 weeks ago 1 0 1 0

Thomas Wakley, the original editor of @thelancet.com was indeed no friend of Dr John Snow.
In happier news, the journal published a 'corrected' obituary in 2013:
www.thelancet.com/journals/lan...

We're glad you had a refreshing visit to the John Snow pub @pwgtennant.bsky.social‬ 😊

1 month ago 10 5 2 0
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a cat wearing sunglasses and a chain around its neck is sitting on a blue couch . Alt: a cat wearing sunglasses and a shiny chain around its neck is sitting on a blue couch looking fabulous.

Typo in student paper: Single-bling randomized control trial

1 month ago 22 3 3 1

@spacecowboybooks.bsky.social Thanks for a very useful feed! Only minor quibble: The feed seems to "refresh" every time I go away from it (to another feed) and back - losing my current "reading progress". Other similar feeds do not appear to refresh as often. Possible to reduce "refresh rate"?

2 months ago 3 0 1 0
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Thanks, I'll take a closer look!

2 months ago 0 0 0 0

Casual causal?

2 months ago 2 0 0 0

Causal inference coming to an unblinded trial near you!

Hoping to read it more carefully soon and understand how it relates to previous efforts in measuring and handling unblinding (e.g. blinding indices) and to choice of control (e.g. active placebo)

#Blinding #Masking #Unblinding #Unmasking

2 months ago 4 0 0 0

... (in an estimation setting, this would probably be estimating differences in beliefs between arms, either with conventional 2x2 measures, or blinding indices). This appears to be a central discussion in many fields, so would appreciate your reflections.

Thanks in advance!

3/3

2 months ago 0 0 0 0

I noticed your warning against conditioning on post-treatment belief (since it is a collider). Just wondering, does this reservation extend more generally to cautioning against testing for success of blinding at all, regardless of doing a stratified analysis of treatment effects by belief? ...

2/3

2 months ago 0 0 1 0

(cross-posting from Disqus at MedRxiv now that I found this post: hope that's okay!)

Thanks for an interesting preprint, which I hope to read more carefully soon. I am not particularly well versed within causal inference so apologies if the question is unclear.

...

1/3

2 months ago 0 0 2 0

Previous post about this study:
bsky.app/profile/davi...

3 months ago 3 0 1 0
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3 If feasible and meaningful, have another person check procedures that are not done in duplicate (e.g. trial overlap removal).

5/5

3 months ago 2 0 1 0

Lessons learned:
1 Use automatic data checks (e.g., that all trials are included in analysis, and no more than once), and ensure that they are working as intended.
2 Add useful extra info the appendix for easy validation (e.g. forest plots for all main analyses with outcomes listed).

4/5

3 months ago 1 0 1 0

Correcting these mistakes leads to small changes in estimates but does not change our overall conclusions (NB. two analyses of heterogeneity become statistically significant, but we interpret these with caution).

3/5

3 months ago 2 0 1 0

Some details: One mistake related to incorrect exclusion of a few trials during removal of overlapping trials across meta-analyses). The other mistake was misclassifying a meta-analysis (about attrition but classified as co-intervention) which then entered the wrong analysis.

2/5

3 months ago 1 0 1 0

Errare humanum est ...
(To err is human ...)

While preparing my PhD thesis, I discovered some (minor) errors in which trials and meta-analyses were included for analysis in our meta-epidemiological study.

1/5

3 months ago 5 1 1 1

Sounds great! Would be interesting to compare # original posts across platforms

3 months ago 0 0 0 0

Thanks for the status! Do you have separate numbers for original posts vs reposts and how these compare between Bluesky and X?

3 months ago 3 0 1 0

Webinar - read more and sign up: www.cochrane.org/events/how-t...

On 17 February 2026, Andreas Lundh and Asbjørn Hrobjartsson will host a Cochrane Learning Live webinar about the TACIT tool.

4 months ago 5 1 0 0
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... IN MICE 🐭

jamesheathers.medium.com/in-mice-expl...

Vigtigt med retvisende overskrifter og passende forbehold for ekstrapolering til mennesker.

#JustSaysInMice #InMice #IMus

5 months ago 0 0 0 0

Many seemingly overlapping terms: MCID, MID, minimally relevant different (MiReDif), smallest effect size of interest (SESOI), smallest worthwhile difference (SWD) ...

Different traditions? Would be nice with a good overview.

5 months ago 1 0 0 0

Thanks, I'll check it out!

5 months ago 1 0 0 0

Any specific critical literacy resources from philosophy you would recommend?

5 months ago 1 0 1 0

Happening TODAY at 3pm GMT 👇

5 months ago 2 2 1 0
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Introduction to INSPECT-SR Training Workshop December An introductory 2-hour online workshop will introduce participants to the INSPECT-SR tool for assessing trustworthiness of randomised controlled...

Have increased capacity for this December INSPECT-SR online training workshop following a successful 1st event today. Book here: www.trybooking.com/uk/FKHV

5 months ago 12 7 0 2

Recent trial with potential data problems @bmj.com. Great with IPD available for checking.

Helpful/feasible with early standard checks in submission? E.g. onlinelibrary.wiley.com/doi/full/10....) or INSPECT-IPD (in development, www.sciencedirect.com/science/arti..., @jdwilko.bsky.social)

5 months ago 2 0 0 0

In Danish, it is similar with the word for male cousin (perhaps more in humorous context). E.g., "I saw this weird cousin in the train today ..."

5 months ago 0 0 0 0
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