This study examines the association between playing car racing video games and being involved in a real car accident (as the driver).

a. Assume that the exposure of interest is the long-term effects of habitually playing these video games. In a case-control study, how would he select cases and controls and measure exposure?

b. Now imagine the exposure of interest is whether the use of such games in the hour immediately preceding driving increases short-term risk. What is a design for studies of short-term effects of intermittent exposures? Lay out how such a study would be carried out for this research question.