Unfortunately, we don't have a good way to measure the difference between "few sick days due to good health" and "few sick days because came into office sick".

Unfortunately, we don't have a good way to measure the difference between "few sick days due to good health" and "few sick days because came into office sick". Or, for that matter, "many sick days due to unsolvable chronic illness but doing their best" and "many sick days due to eating an entire bag of Doritos during lunch and feeling ill".