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I have met so many wonderful people along my SAS journey, they are precious like Sapphire to me.
Now I am trying to organize the common SAS functions and procedures I have used on a daily basis, summarize the different CDISC domains that I have worked on and some statistical method I have encountered.
Background story: Last time, when we used R to calculate the sample size, we specified Type I error α and Type II error β, but what does the meaning behind α and β? Review: We define the “best” sample size that has less variation of the sample mean from sample to sample.
Factorial Design allows the investigation of sets of categorical predictors, and the interaction between them. Today we will go over some basics of One Fixed Factor and One Random Factor Design. Keywords: Factor: categorical predictors Fixed Factors: Estimate the difference in means between groups defined by specified categorical predictors. e.x. ANOVA model, one measurement per subject. Random Factors: Estimate the variance…
Background Movie: Based on my taste, 我不是药神 Drug Deal/Dying to Survive is one of the best movies in 2018. It was based on a true story that some cancer patients use a kind of cheap Indian medicine (Veenat 100) as a substitution of the authentic Novartis Glivec 400 to prolong their lives. Besides the touching story, Veenat 100 is a…
Background Story: Once, we need to do an Interim Analysis, I didn’t understand why we need to do it. Later I learned in Clinical Trial studies, our ultimate goal is trying to get approval for FDA submission at the end of studies. While exhausting and long progress, sometimes we perform Interim Analysis before the completed trial to access Safety, Futility,…
Background Story: We often use different populations (Safety, Efficacy, ITT, Per-Protocol) to generate Clinical Trial Reports, but what are the differences between the populations? Today we will go over the basics of Intention to Treat and Per-protocol Analysis.
Background Story: Once my boss asked me to review an Open CDISC report for SDTM dataset packages. I wasn’t sure what to do at first. With the help of my colleagues, I gradually develop a sense of how to review the CDISC report. I’d like to share some review processes and common Open CDISC Summary from PINNACLE21.
Today I want to share some basic Unix commands I use recently in Putty. Directory: Direct the path to a certain location cd /… cd – {home directory} pwd {show current working directory} Files: List current files ls {path} ls -l {date,size, permission} Check/Change Access: Read is 4. Write is 2. Execute is 1. ls -lah xyz(u,group,everyone else)…
In data science, we usually classify variables into two big types: Continuous(age), Categorical(sex). What about the variables in clinical trials/statistics? How many different types do we have? Little goal: Today we will learn the six common types of variable in statistics? How to use and present them in clinical trials?
SAS day 56: ANYALPHA Background Story: Once we had an excel sheet with an extreme variety of date formats that don’t make sense. Is there a method to clean the data so they will be meaningful dates? Raw Data: Solutions Ideas: After observing the data structure, we notice it either starts with a letter or number. Therefore, we will apply…
SAS day 55 Background Story: Once we need to generate an Adverse Event listing for the medical team to review in excel, I was amazed by my colleague’s colorful output from SAS. I was just simply happy to look at the output! Example: I will use SAS.cars to generate the output SAS Code: *—————————–*; * To generate excel…