Rates

How do you represent Incident Rate?

(# of new cases during a specific time) / (# of people at risk during that specified time.)

How do you represent Attack Rate (Primary Attack Rate)?

(# of new cases during a short period of time)/ (population that is at risk in the beginning of that time)

How do you represent Secondary Attack Rate?

(# of new causes among the contacts)/ (the total # of contacts)

What’s Prevalence in general?

(# of new & existing cases at a certain time you’re evaluating (point or period))/ (# of people at that certain point in time your evaluating).

What’s Frequency?

(# of cases)/in population