New Zealand rider Andrew Nicholson comes to grief at Burghley.
Information gathered will be used to help develop safety within the sport of eventing.
The survey was developed by Dr Patricia Evans at Utah State University, and has been adapted for wider use with help from Ken Law, who hosts a UK-based website, www.ridingsafely.net, and Denzil O'Brien, who has recently completed a five-year surveillance programme on the risks involved in the sport of Eventing.
The Equestrian Federation of Australia's national safety officer, Bob Powles, also helped in the process.
US law requires that the survey can only be completed by people aged 18 or over.
It is aimed only at those who have had a horse-related injury, not general EFA membership. There is an email address in the survey introduction where respondents can direct any questions they have, such as how to answer a question.
Respondents will not be asked for identifying information - data gathered will be used statistically not descriptively.
Some questions have a distinct US or UK focus.
This is possibly the first time that such a survey has been undertaken across such a wide range of potential respondents.