Period Prevalence - See Also

See Also

• Point prevalence

For example.... In our street of 1000 people on 1st Jan 2011, 200 had a car. Once they have a car nobody changes their car. Each year 365 people buy a car and 265 people get rid of one. The point prevalence of cars in our street as at 1st Jan 2011 is 20% The incidence of car buying is 1 per day. The period prevalence of car ownership in 2011 is 565 or 56.5% (the number of people who, at some point in the year own a car) The point prevalence on 1st Jan 2012 is 30% because 300 people now own a car.