Trying to figure out how to model a categorical predictor in your regression? 

Done this code a million times but can never remember the syntax for the class statement? 

Want to generate exponentiated estimates and confidence intervals?

We'll give examples for binary, 3 levels, 4 levels, and stratified.

Python is a general computer programming language but has recently garnered popularity among data scientists with its versatility, ability to quickly process large data sets, and large library of machine learning models. I taught myself Python two years ago and while there are several Python libraries for epidemiology, I found the libraries were no longer actively maintained, did not interact with pandas (the main data management Python library), or implement causal inference methods (like inverse probability weights). To fill this gap, I created zEpid with the goal of making epidemiologic analyses in Python e-z.

​Short post today on how to use the MEAN function in SAS 9.4. Let's get started.

It seems like every time I need to calculate a mean variable in SAS, I find myself looking up which CALL functions deal with missing values in this way, and which in that way. 

For example, blood pressure readings are often taken 3 times, and then we average those 3 readings together for a mean value. In some code I ran earlier this morning, I kept getting negative values in my "avg_bp" variable. What's up with that? 

Author: Bailey DeBarmore

While I'm not a big fan of p values, sometimes your coauthors, reviewers, or editors ask for them. In this post I'll show you how to calculate p for trend for ordered categories, like in a Table 1, and for adjusted odds ratios or similar regression.

R users: I don't use R much, but encourage you to search for "prop.trend.test" to learn more about trend tests in R.

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