MPD
Try this site first for information about accidents in general:
http://nsc.org/library/rept2000.htm
Another fascinating report is:
A Safety Review and Risk Assessment in Air Medical Transport
Supplement to the Air Medical Physician Handbook (November 2002)
Ira J. Blumen, MD and the UCAN Safety Committee
Mailing Address:
383 "F" Street
Salt Lake City, Utah 84103
Telephone: 801-534-0829
Fax: 801-534-0434
www.ampa.org
This is probably the most comprehensive report on helicopter accidents that you are likely to read. It also contains a comparison of personal risk that is as good as you will get (walking or jogging if crossing an intersection more dangerous than riding motorbikes).
Apart from the analysis of accident data there are: a comparison between HEMS and other Operations; principles of a safety and risk managed program; and risk management - all are covered with the same sure touch.
The report should be compulsory reading for all HEMS operators, HEMS pilots and medical crew members, and any organisation that is seriously interested in making an impact on helicopter safety.
I have no vested interest in this organisation or the authors - just recognise an excellent piece of work when I read it.