Case-Control studies represent one form of analytic study that provides information on the relationship between causal factors and injuries.  In a case-control study, subjects who have been injured are identified and their past exposure to suspected causal factors is compared with that of controls (persons who have not been injured).

Many case-control studies ascertain exposure from personal recall, using either a self administered questionnaire or an interview. The validity of such information will depend in part on the subject matter. People may be able to remember recent events quite well.  On the other hand, long term recall is generally less reliable.

Source: Chapter 8: Case-control and cross-sectional studies, Epidemiology for the Uninitiated