Suppose two researchers wanted to determine if aspirin

Last updated: 7/12/2022

Suppose two researchers wanted to determine if aspirin reduces the chance of a heart attack.Researcher 1 studied the medical records of 500 randomly selected patients. For each patient, he recorded whether the person took aspirin every day and if the person had ever had a heart attack. Then he reported the percentage of heart attacks for the patients who took aspirin every day and for those who did not take aspirin every day. What type of study did Researcher 1 conduct? A. Observational B. Experimental C. Survey D. None of the above