In 2010, a total of 244,258 motor vehicle collisions (MVCs) were reported in Puerto Rico, resulting in 408 deaths. A group of epidemiologists from the Department of Health decided to investigate whether there is a relationship between the use of seat belts (exposure) and the occurrence of death in CVM. They obtained a random sample of 100 case forms from adult individuals who died of CVM. These forms documented whether or not the deceased individual was wearing a seat belt. Among these individuals, 40 were not wearing seat belts and 60 were wearing seat belts. The researchers obtained a sample of 200 other CVM-involved individuals (controls) who had survived the event. These individuals had conditions similar to the first 100 (cases) in terms of age, sex, vehicle speed, and crash location. Of these 200 individuals, 50 were not wearing seat belts and 150 were wearing seat belts.

*** We consider NOT wearing a seatbelt as exposure and death as the outcome we would like to prevent.

6. Fill in the spaces of the 2x2 table (contingency) with the data obtained from the study.

	Deaths	Survivors	Total
Not belt
Belt
TOTAL

7. What is the design of this study?_______________________________

8. Calculate the value of the best predictor of the association for adults involved in CVM between dying and not wearing a seat belt. Perform the calculation.

This value is=________

9. How many adult MVC deaths (percentage) do you estimate could be prevented in 2010 in the population if everyone wore a seat belt? __________. Perform the calculation