I have a few suggestions that might make this more useful for an international audience.

- I suggest that you offer people the option to use long dates; 7th June 1980. When reading in a hurry a little redundancy can be helpful.

- abbreviations like DOB, ZIP, etc., are not necessarily universally understood.

- the address should be a free text multiline field to allow addresses to be written in the customary form in different countries. Not everyone has a house number or postal code.

As all the information is optional it would probably be useful to include a field for things like national ID numbers, social security numbers, etc. The point is that this number give emergency medical facilities a way to quickly access a person's medical records in some countries.