<unk>  (sometimes referred to as<unk>  proportion) is a measure of disease frequency which counts the proportion of a candidate population that becomes diseased/develops disease over a specified period of time.<unk>  measures occurrence of new cases of disease. It involves the transition from one state to another, such as non-disease to diseased state<unk>  of disease) or diseased to non-diseased<unk>  of cure).
Cumulative incidence
Period prevalence
Point prevalence
Block design
Biased sample
Sample size
Attributable risk
Number needed to treat