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Dec 6, 2015 09:51
8 yrs ago
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English term
alpha-spending function according to O’Brien and Fleming
English to Latvian
Medical
Medical (general)
clinical trial, statistics
The study uses a group-sequential design using an alpha-spending function according to O’Brien and Fleming
Nevaru atrast daudz maz ticamu latvisko variantu - varbūt kādam ir trāpījies ceļā?
Nevaru atrast daudz maz ticamu latvisko variantu - varbūt kādam ir trāpījies ceļā?
Reference comments
357 days
Erzsébet Czopyk
Hungary
Hungary
Specializes in field
Hungary
sworn translator, linguist, DPO
Native in: Hungarian (Variant: Hungary) 
Works in: Russian to Hungarian, Hungarian to Russian, Latvian to Russian, and 10 more.
Related KudoZ points
:
16
Reference:
Alpha spending functions that approximate O’Brien-Fleming
Alpha spending functions that approximate O’Brien-Fleming or Pocock Boundaries are as follows:
O’Brien−Fleming:α1(t∗)=2−2Φ(Zα/2/t∗−−√),
Pocock:α2(t∗)=αln(1+(e−1)t∗),
where Φ denotes the standard normal cumulative distribution function. To solve for the boundary values zc(k), we need to obtain the joint distribution of Z{(1), Z(2),…, Z(k)}. In most cases, this distribution is asymptotically multivariate normal, and the covariance matrix Σ is simple when the test statistics involve the same parameter at each interim analysis.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4024106/
The use of alpha spending functions has become a powerful tool in designing group sequential trials since 1990
The O'Brien-Fleming Alpha Spending Function
Description
Stipulates alpha spending according to the O'Brien-Fleming spending function in the Lan-Demets boundary construction method. Its intended purpose is in constructing calls to GrpSeqBnds and PwrGSD.
https://rdrr.io/rforge/PwrGSD/man/Ch3-ObrienFleming.html
O’Brien−Fleming:α1(t∗)=2−2Φ(Zα/2/t∗−−√),
Pocock:α2(t∗)=αln(1+(e−1)t∗),
where Φ denotes the standard normal cumulative distribution function. To solve for the boundary values zc(k), we need to obtain the joint distribution of Z{(1), Z(2),…, Z(k)}. In most cases, this distribution is asymptotically multivariate normal, and the covariance matrix Σ is simple when the test statistics involve the same parameter at each interim analysis.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4024106/
The use of alpha spending functions has become a powerful tool in designing group sequential trials since 1990
The O'Brien-Fleming Alpha Spending Function
Description
Stipulates alpha spending according to the O'Brien-Fleming spending function in the Lan-Demets boundary construction method. Its intended purpose is in constructing calls to GrpSeqBnds and PwrGSD.
https://rdrr.io/rforge/PwrGSD/man/Ch3-ObrienFleming.html
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