Final answer:
Absolute risk reduction quantifies the difference in risk between two groups, such as between a treatment group and a control group in a clinical study, and it is used to measure the effectiveness of a health intervention.
Step-by-step explanation:
The statement concerning absolute risk reduction that is true is: C) It quantifies the difference in risk between two groups. Absolute risk reduction is a measure in epidemiology and clinical research studies to determine the effectiveness of a health-related intervention. It is calculated by finding the absolute difference in the event rate of a disease or condition between two groups, such as a treatment group and a control group.
To illustrate absolute risk reduction using the provided information, if a new medication was tested and 45 out of 224 patients developed the disease in the treatment group, while 68 out of 224 patients developed the disease in the control group, the absolute risk reduction would be the difference in the proportion of patients developing the disease in both groups. For the treatment group, the risk is 20.1% (45/224), and for the control group, it is 30.4% (68/224), so the absolute risk reduction is 10.3% (30.4% - 20.1%). This indicates the treatment confers a benefit in reducing the risk of developing the disease.