A five year study was conducted among 5,000 men older than 65 years to examine the relationship between heavy alcohol consumption and the onset of atrial fibrillation. The men were assessed each year. Men who drank heavily contributed a total of 12,500 person-years of observation and 250 of those who drank heavily developed atrial fibrillation. A total of 24,000 person-years were observed for the entire study. And 100 men who did not drink heavily developed atrial fibrillation.

What was the cumulative incidence of atrial fibrillation in the study assuming no men had atrial fibrillation at the beginning of the study ? What was the point prevalence of atrial fibrillation at the beginning of the study ? What was the incidence density among heavy drinking men? What was the incidence density among non-heavy drinking men ? What was the rate ratio and interpret ?