Hello, I am analyzing a hospital dataset which provides demographic, diagnostic, and procedural data for each discharged patient.

There are 15 procedure code variables for each patient (but not all patients had 15 procedures). These are labeled cpt1, cpt2, cpt3, etc. I would like to identify the most common procedure codes, but do not know how to look at each variable simultaneously. For example, I don't want to just know what is the most common cpt1 code, but rather the most common code out of all CPT variables.

I am using Stata/SE 14.2.

I appreciate any help!