What is the primary difference between risk and prevalence?1 pointPrevalence describes the number of diseased persons present in the population divided by the number of persons in the population in a specified time period, whereas risk describes the number of newly diseased person present in the population divided by the number of at-risk persons in the population in a specified time period. Prevalence describes the number of diseased person present in the population in a specified time period whereas risk describes the number of people who die from the disease in the population in a specified time period.Risk describes the number of diseased persons present in the population divided by the number of persons in the population during a specified time period, whereas prevalence describes the number of newly diseased person present in the population in a specified time period divided by the number of at- risk persons in the population.

What is the definition of “Prevalence”?*1 pointThe total number of cases of a disease or condition.Number of current cases for a particular condition over the past 12 months.Number of new cases for a particular condition over the past 12 months.Number of new cases for a particular condition.

What is the definition of the risk difference?Question 4Answera.The difference in proportion of subjects with the outcome of interest in each groupb.The number of patients you need to give an intervention to in order to prevent one additional negative outcomec.One minus the risk ratiod.The probability of an event in the treatment group divided by the probability of an event in the control group

What does "population at risk" (PAR) refer to in epidemiological studies?Select one alternative:Members of the population who are capable of developing the disease or condition being studied.Only individuals who have already developed the disease or condition being studied.Members of the population who are actively immune to the disease or condition being studied.Only individuals who are incapable of developing the disease or condition being studied.

True or False: The denominator of a risk is not fixed by the “at-risk” population size at the beginning of a study observation period. 1 pointTrueFalse

Once the study population has been defined, the denominator of a risk is affected by which of the following? (You must choose all that apply to receive credit for this question; no partial credit will be awarded.)1 pointloss to follow-upmigration who is at risk of developing the health outcomedeathsbirths