Count refers to what in epidemiology?

• A. The rate of disease
• B. Time to onset
• C. Number of cases, number of deaths
• D. The proportion of affected in population

Answer: (C)

Count is the raw tally of events observed, such as the total number of disease cases or deaths in a defined population over a specified period. It is the absolute number, not adjusted for population size or time. Rates, in contrast, express those counts per a unit of population per unit of time (for example, cases per 100,000 people per year) and are used to compare across groups or over time. Time to onset refers to the latency before a disease event occurs and isn’t a tally. The proportion of affected describes the fraction of the population that is affected, a ratio rather than an absolute count. So the count best reflects the total number of cases or deaths observed.