Topic summary

Washout with a one-week half-life: the arithmetic

Research Methods › N-of-1 designs effect size data table worked example Wiki

This is a generated summary. It shows the 9 most-liked posts from a topic of 97, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

s.kimaniTL220 Nov 2024#1

Community wiki post. Any member at trust level 3 or above can edit this post; every edit is recorded. Last edited by PharmNotes_Whitfield on 27 Apr 2025.

1 Dec 2024 — crossref_check: Plain-language pass on the opening paragraph.
27 Apr 2025 — PharmNotes_Whitfield: Corrected an arithmetic slip in the second example.

Editors: crossref_check, PharmNotes_Whitfield

Washout with a one-week half-life: the arithmetic — setting out what I have, and where I think it stops being reliable.

Washout: setting out the arithmetic in full, because I have had to do it twice and I would rather nobody else did.

Every step is shown. If the answer is wrong the error will be visible, which is the point of writing it out rather than posting the result.

51 likes 20mo

t.nardoneTL3Regular23 Nov 2024#10

l.chevalier, post #4: On washout: the maintained page in the documentation commons covers the general case with citations and a review date, which is more reliable than any reply here including this one. Go to post

Agreed on all of that, and I have nothing to add to it.

27 likes in reply to #4 20mo

f.villalobosTL224 Nov 2024#11

Committing to post the result before you know it is a useful precommitment, and this subcategory is a reasonable place to make it.

The part I am sure of is shorter than the part I have written.

29 likes 20mo

f.fenwickTL3Regular26 Nov 2024#20

Post #18 describes the usual case. This is about the unusual one.

Careful with the language on washout. "Not detected" and "not present" are different findings and the first is a statement about the method.

30 likes 20mo

s.ivaturiTL229 Nov 2024#35

Adding a reference point for washout. Mine is a single case, collected without controls, and I am posting the method alongside it so it can be discounted appropriately.

29 likes 20mo

trough_indexTL3Regular30 Nov 2024 · edited#41

A washout period between conditions is what stops one bleeding into the next, and its length should be set by the half-life rather than by convenience.

30 likes 20mo

n.kirchnerTL22 Dec 2024 · edited#50

Reading this washout thread as someone who came in with a fixed view: the third and seventh replies moved me and the confident ones did not.

29 likes 20mo

dr_okonkwoTL4 Moderator4 Dec 2024 · edited#62

trough_index, post #41: A washout period between conditions is what stops one bleeding into the next, and its length should be set by the half-life rather than by convenience. Go to post

Bookmarking this. I will come back when I have something worth adding.

32 likes in reply to #41 20mo

f.fontaineTL27 Dec 2024#82

taper_file, post #55: The arithmetic in post #53 is right; the assumption feeding it is the part to check. It does not tell you about anybody else, which is why aggregating these accounts does not produce evidence of the kind people want it to. That is one dataset and I would not build a rule on it. Go to post

If someone has run washout properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.

31 likes in reply to #55 20mo

Read the full topic (97 posts)

This topic was referenced in

Blinding yourself: practical methods and their limits — the long versionResearch Methods › N-of-1 designs · 11 replies

Suggested topics

Topic	Participants	Replies	Views	Activity
An ABAB design with a data table and honest limitations Research Methods › N-of-1 designs effect size confounding worked example An ABAB design with a data table and honest limitations Writing it up because I had to work it out twice and would rather nobody else did. An honest uncertainty about ABAB design rather than a disguised…		2	45k	5mo
Pre-registering a personal experiment, seriously Research Methods › N-of-1 designs worked example data table effect size confounding Pre-registering a personal experiment, seriously — setting out what I have, and where I think it stops being reliable. A narrow question about pre-registering a personal experiment, deliberately narrow,…	+96	119	58k	14mo
Blinding yourself: practical methods and their limits — the long version Research Methods › N-of-1 designs worked example effect size confounding data table Blinding yourself: practical methods and their limits — the long version Writing it up because I had to work it out twice and would rather nobody else did. A narrow question about Blinding yourself,…	+7	11	1.8k	22h
Coming back to: Why most self-reports here are not experiments, and that is fine Research Methods › N-of-1 designs worked example data table effect size Solved Closed The question in the title: Why most self-reports here are not experiments, and that is fine I will give what I have already checked below so nobody repeats it. A question about what a single-person experiment…	+56	62	11k	4mo
Why most self-reports here are not experiments, and that is fine Research Methods › N-of-1 designs confounding worked example data table effect size Closed Why most self-reports here are not experiments, and that is fine — that is the question, and I have not found it answered plainly anywhere I have looked. A question about what a single-person experiment can…		2	46k	11mo

Related topics — sharing the tags effect size, data table, worked example

Topic	Participants	Replies	Views	Activity
Immortal time bias in a claims-database study — one year on Evidence › Study critique effect size risk of bias confounding Solved Posting this under the heading it deserves: Immortal time bias in a claims-database study — one year on Everything below is what sits behind that. I would like to disagree carefully with the settled view on…	+41	46	3.7k	22h
Washout: how long is long enough, and for what purpose Pharmacology › Pharmacokinetics semaglutide missed dose worked example Closed Washout: how long is long enough, and for what purpose — setting out what I have, and where I think it stops being reliable. A narrow question about washout, deliberately narrow, because the broad version has…	+63	70	13k	10mo
Revisiting: Semaglutide formulation: what is in the licensed product besides the peptide Compounds › Semaglutide effect size type 2 diabetes randomised trial Solved Posting this under the heading it deserves: Revisiting: Semaglutide formulation: what is in the licensed product besides the peptide Everything below is what sits behind that. I have spent a fortnight trying…	+72	77	7.2k	19mo
Trifluoroacetate content and its consequences Analytics › Impurities & related substances water content data table forced degradation counter-ion content Trifluoroacetate content and its consequences — setting out what I have, and where I think it stops being reliable. What changes if the standard account of trifluoroacetate content is wrong? I ask because I…	+123	134	31k	5mo
The decimal-point error, and the habit that catches it Practice › Reconstitution syringe units concentration maths worked example bacteriostatic water The decimal-point error, and the habit that catches it Writing it up because I had to work it out twice and would rather nobody else did. An honest uncertainty about decimal-point error rather than a…	+110	121	10k	7mo