Quite often, I suspect. Technically, they should be able to use the transporter and buffer to copy and save the state of people too.
Log all the lifesigns on the ship. This is done every morning, or whenever people board or leave the ship, or just before people head out on an away mission.
Compare log to previous saved log. If there’s any difference, notify command to investigate.
When beaming an away party back, beam them directly into quarantine until they’ve been checked against their medical records, or the pre-transport saved state.
If the ship is boarded during an attack, beam all non-registered lifeforms into space (or into the replicator nutrient pool for reuse)
If an away team member is killed, restore from your transporter backup.
Struggling with an engineering problem? Copy a few more Geordies from the stored transporter state.
Quite often, I suspect. Technically, they should be able to use the transporter and buffer to copy and save the state of people too.
It might slightly ruin the drama.
That’s how you get a ship full of amoral Garys.