Easy in theory, but not in practice. For good reasons there are very strong privacy protections in place for medical records, and significant administrative barriers. And this is not even getting into the technical / infrastructure challenges.

Maybe feasible for a VC funded company with several million dollars and >20 FTEs. Less so for an academic lab with a few grad students and postdocs being paid with pocket lint.

I was thinking it could be self reported in-app. After using the app and saving coughs, if you get a test result you have the option of adding it with the test date.