Assist. Prof of Biostatistics & Prof of Cardiology, AI engineering (MSc student) @NisantasiEdu
Aug 15, 2021 • 14 tweets • 4 min read
Sayın meslektaşım: Alıntıladığım tweet serinizde uzun uzun, İngiltere verilerini (rakamlarını) bilerek/isteyerek ya da bilmeden/istemeden yanlış yorumlamışsınız. İki durumda da sizin için üzülürüm! 1/
Bilerek/isteyerek yapıyorsanız, ki buna ihtimal vermek istemiyorum. Ancak, bilmeden/istemeden yanlış yorumluyorsanız, birçok insanın vebaline girmiş bulunursunuz
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Feb 2, 2021 • 11 tweets • 6 min read
Our clinical prediction model (CORONATION) published in J of Med Virol. We included over 60.000 hospitalized pts w/ COVID-19. onlinelibrary.wiley.com/doi/pdf/10.100… 1/
Number of death/ICU and total no. pts according to EuroStat geographic NUTS 2/
Jun 2, 2019 • 21 tweets • 9 min read
Multiplicty in Clinical Trial is really a disturbing issue for statisticians and trialists! (and for me😬)
b/c there is no consensus on multiplicity issue: When, Why and How to deal with it?
-I’ll try to explain by using *frequentist* point of view 1/
Briefly, multiplicity is using many (multiple) comparisons. It increases the likelihood that a chance association could be deemed causal. In other words, we carry out multiple tests, it becomes highly likely that one of these tests will be significant by chance.
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May 26, 2019 • 9 tweets • 4 min read
A brief comment on proportional hazard assumption;
Many RCTs use «TIME-TO-EVENT» as a primary endpoint. Cox regression model is used to get summary measure (HR) and 95% CI.
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Key assumption of Cox model is PROPORTIONAL HAZARD assumption (PHA). PHA means that the ratio of hazards between any two fixed sets of covariates not vary with time. If PHA is largely violated, Cox cannot be used! HR given by Cox, only reflects average tx effect which useless 2/
Apr 23, 2019 • 16 tweets • 7 min read
PS is the probability of tx assignment based on baseline covariates. b/c PS idea mimics an RCT, researchers've extensively used.
used PS with caution instead of banning is a solution. In the next tweets, I’m going to specify some critics on PS methods.1/
