In an office environment, not sure if healthcare is different, it can sometimes be considered career suicide to not go to the office christmas parties unless you have a justifiable conflict (ie someone died (produce death certificate
, or out of town)
The office party is part of your job. Its purpose is to bring together coworkers and colleagues for a bit of camaraderie and some well-deserved recognition. If this is not your idea of a great time, then consider it work, put on your best attitude and go.