Using a statistical method in an applied context for (probably) the first time. How do I convey this? I am a graduate student in statistics, writing the methods and data analysis section of an epidemiology paper. I used an obscure but highly relevant statistical method to analyze our data. I genuinely believe this is the first novel application of this method outside of toy problems in highly theoretical paper.

What I want to say is: Previous research on METHOD XX has been limited to statistics and econometrics literature

This seems too sweeping a claim for me to make though. It's entirely possible that someone, somewhere has used this method before. It is also a nightmare to cite. How do you cite the absence of evidence?

So, what is the best way to convey this? Is it as simple as tempering my initial statement a bit: Previous research on METHOD XX has largely been limited to statistics and econometrics literature. Should I get rid of this statement all together?
In lots of papers I've seen a phrase:


  According to (or to the best of) the author's knowledge, this is the first time that method XX has been applied to YY.


which seems fair and safe enough.