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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.
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…
SAS day 54 We know Format is a common function to convert date in SAS, such as, format aestdt date9. . What about Proc Format? When and how should we use it? Case 1: Numeric to Character Presentation When data are coded in numerical, we would like to display it in characters in Frequency tables. Syntax: Proc Format;…
sas day 53: A classical AE table is by SOC (body system class) and Preferred term( AEDECOD). The overall AE table could last for over 100 pages long. What if we’d like to see the count and confidence Interval for some Special Interested Adverse Event (SIAE) within the whole safety population. Challenge: How to generate an AE table with confidence…
R day 3 In clinical trial studies, P-value is critical for measuring drug efficacy. Typically, the statistical analysis Plan will describe statistical significance as: P-value <0.05 for two-tailed Log Rank Test. Recently, I came across a study with the statistical significance as P-value <0.025 for one-tailed Log Rank test in the analysis plan. Question: Does two-tailed P-value= 0.05 means the…
SAS Day 52 Once I use SAS proc import a Special Adverse Event dataset, everything looks good, except the variable name was directly from excel and has space and special characters like “/” (EOI/ Search) Little Challenge: How to Rename a variable with space or special characters? Basic Rename Syntax: *1. within dataset data a; set a; rename old_name=new_name; run;…
Inspired by Joe Wang and Tony Qi, i did a summarization of Survival analysis and Restricted Mean Survival Analysis.
Restricted Mean Survival Analysis
ADaM day 7 ADDV protocol deviation dataset identifies occurrences of sponsor-defined deviations, which is a list specified for every study. For example, the description of deviation can be Positive Drug Screen, PK labs not drawn in the proper window. A Sample ADDV Dataset key variables：subjid, dvstdt, dvcatcd, dvdeter, dvdesc , dvdact, dvact1, dvtype, dvstype. Key variable indications: dvcatcd=”DV Category Code”…
SAS day 51: Proc Contents Background story: One day, we need to search for a particular variable from 90 datasets. It would be a mission possible without Yajnes’s trick of Proc Contents.