1 Never use a microwave or conventional oven to pre-heat your flask. 2  If your flask has not been used for some time, rinse with warm water to remove any residual odours.  DO NOT overfill your flask. Leave sufficient space in the neck to fit the stopper.
Prevalence is a measure of disease that allows us to determine a person's likelihood of having a disease. Therefore, the number of prevalent cases is the total number of cases of disease existing in a population.
Statistical Terms. Frequency is the number of people who were similar for a given characteristic. For example, 25.2 million adult Americans reported vision loss. Prevalence is a measurement of all of the individuals in a population affected by a condition within a particular period of time.