Background: Five major organizations recently published guidelines for using statins to prevent atherosclerotic cardiovascular disease (ASCVD): in 2013, the American College of Cardiology/American Heart Association (ACC/AHA); in 2014, the United Kingdom's National Institute for Health and Care Excellence (NICE); and in 2016, the Canadian Cardiovascular Society (CCS), the U.S. Preventive Services Task Force (USPSTF), and the European Society of Cardiology/European Atherosclerosis Society (ESC/EAS).

Objective: To compare the utility of these guidelines for primary prevention of ASCVD.

Design: Observational study of actual ASCVD events during 10 years, followed by a modeling study to estimate the effectiveness of different guidelines.

Setting: The Copenhagen General Population Study.

Participants: 45 750 Danish persons aged 40 to 75 years who did not use statins and did not have ASCVD at baseline.

Measurements: The number of participants eligible to use statins according to each guideline and the estimated number of ASCVD events that statins could have prevented.

Results: The percentage of participants eligible for statins was 44% by the CCS guideline, 42% by ACC/AHA, 40% by NICE, 31% by USPSTF, and 15% by ESC/EAS. The estimated percentage of ASCVD events that could have been prevented by using statins for 10 years was 34% for CCS, 34% for ACC/AHA, 32% for NICE, 27% for USPSTF, and 13% for ESC/EAS.

Limitation: This study was limited to primary prevention in white Europeans.

Conclusion: Guidelines recommending that more persons use statins for primary prevention of ASCVD should prevent more events than guidelines recommending use by fewer persons.

Primary Funding Source: Copenhagen University Hospital.