Author Archives: pmean

Recommended: The COMPare Project

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One of the many problems with medical publications is that researchers will choose which outcomes to report based on their statistical significance rather than their clinical importance. This can seriously bias your results. You can easily avoid this potential bias by specifying your primary and secondary outcome measures prior to data collection. Apparently, though, some researchers will change their minds after designating these outcome variables and fail to report on some of the outcomes and/or add new outcomes that were not specified prior to data analysis. How often does this occur? A group of scientists at the Centre for Evidence-Based Medicine at the University of Oxford are trying to find out. Continue reading →

PMean: A book review of my first book

I wrote a book about nine years ago and interest in it has largely died down. Perhaps I should write a second edition. Anyway, I ran across a book review that I had not seen before. It was published in 2006, but I never noticed it until now. Sarah Boslaugh wrote the review and it got published in MAA Reviews (MAA stands for Mathematical Association of America). It says some nice things like my approach was “fresh.” Dr. Bosluagh also likes my web site, according to the review. Continue reading →

PMean: My Google Scholar profile

A while back, I set up a publication list in Google Scholar. It tracks the number of citations received by each article that I published. One of my articles has a massive 287 citations. I’m not the first author on this or on an of the other articles that received 100+ citations. So I’m mostly riding on the coattails of some very good researchers. Continue reading →

PMean: Nonlinear regression for the difference of two exponentials

I wanted to provide an overview of how you analyze a classic nonlinear regression model. It is a difference of two exponential functions. This nonlinear function is used commonly in pharmocokinetic models and is a simply way to model the oral administration of a drug. I want to show how the model works in a mathematical sense and then how you fit it using R. Continue reading →