Exit letter question.

I worked in a retirement home for a short time quite a while ago and I received a letter in the mail today asking me to fill out this form on why I left. The letter also stated that they were experiencing a lot of turnover and wanted to find out why. Although, it is optional to put down my name, I am still leery of filling it out as you never know who will read it and figure out who I am. I didn't leave on bad terms, it was just a place with way too many high acuity patients to take care of. Would any of you folks, fill this form out or not?