What is the population at risk (i.e., the denominator population) for each of the following diseases or conditions? Explain your answers, being sure to focus on person, place, and time.

a. Workplace homicide b. Recurrence of melanoma

Question 2: A study team wishes to study childhood asthma in an elementary school. Over a five-year period, each new student provided medical record information that included previous diagnoses of asthma. The student population averaged 600 students, and 400 new students were admitted during the five-year study period (unique individuals).

The study team found that 50 of the new student medical records indicated a previous diagnosis of asthma. Which of the following measures of frequency can be calculated? If the measure can be calculated, perform the calculation. If the measure cannot be calculated, explain why not.

a) Incidence rate of childhood asthma b) Case fatality rate of childhood asthma   c) Period prevalence of childhood asthma