This study isn’t based on VAERS data, it’s from the UK. The design tracks their medical record system, under reporting shouldn’t be a big concern Edit: > We

This study isn’t based on VAERS data, it’s from the UK. The design tracks their medical record system, under reporting shouldn’t be a big concern Edit: > We assessed the temporal association between COVID-19 vaccination and cardiac adverse events using hospital admissions with diagnoses of myocarditis or pericarditis, and cardiac arrhythmias. Maybe there is differential reporting based on who shows up at the hospital with Covid vs just vaccine induced side effects, but it’s sort of hard to design a large scale study to pin this down. The methodology seems sound enough to fairly track at least those ill enough to go to the hospital