The phrase "completeness sake" means doing something just to ensure everything is included or considered, without necessarily expecting a specific result or benefit. Full definition
I'm sure you can find plenty of reports out there on the product (Mark over at The Shutterwhale has a great piece on the product, plus much better photos than I could ever hope to take), but nonetheless for completeness sake I will pen one of my own. (milelion.com)
So if the numbers are so small in both group just show them for completeness sake and then be done with the mortality piece and move on, rightly, to morbidity. (skepticalob.com)
The result is now clear, but for completeness sake, let's also dissolve the last pile. (politics.stackexchange.com)