Guidelines for using statins to treat high cholesterol and prevent cardiovascular disease are projected to result in 12.8 million more U.S. adults taking the drugs, according to a study.
The findings for the first time quantify the impact of the American Heart Associations new guidelines (http://circ.ahajournals.org/content/early/2013/11/11/01.cir.0000437738.63853.7a), which were issued in November and generated controversy and speculation about who should be given a prescription for statins.
As published March 19 on the website of the New England Journal of Medicine, a team led by researchers at the Duke Clinical Research Institute in Durham, N.C., analyzed health data and found that most of the additional statin users under the new guidelines would be people older than 60.
We sought to do a principled, scientific study to try to answer how the new guidelines might affect statin use, particularly as they focused eligibility on patients with an increased risk of developing cardiovascular disease, Michael J. Pencina, PhD, the studys lead author and professor of biostatistics at DCRI, said in a news release.
By our estimate, there might be an uptake in usage as a result of the guidelines, from 43.2 million people to 56 million, which is nearly half of the U.S. population between the ages of 40 and 75.
Pencina and colleagues from McGill University in Montreal and Boston University used the National Health and Nutrition Examination Surveys for their analysis, focusing on 3,773 participants ages 40 to 75 who had provided detailed medical information, including fasting cholesterol levels from blood tests.
The new guidelines expand the criteria for statin use to include people whose 10-year risk of developing cardiovascular disease, including stroke, is elevated based on a risk-assessment score.
The researchers determined the new guidelines could result in statin therapy recommendations for 49% of U.S. adults ages 40 to 75, an increase from 38%.
The increase is more pronounced among adults free of cardiovascular disease who are older than 60, with 77% recommended for statin use under the new guidelines versus 48% under the previous standards. This contrasts with a modest increase from 27% to 30% among U.S. adults ages 40 to 60.
Those most affected by the new recommendations are older men who are not on statins and do not have cardiovascular disease. Under the earlier guidelines, about 30.4% of this group of men ages 60 to 75 were recommended for statin use. With the new guidelines, 87.4% of these men would be candidates for the therapy.
Similarly for healthy women in this age group, those recommended for preventive statin use are projected to rise from 21.2% to 53.6%.
The biggest surprise of the research was the age-dependent split for those affected by the new guidelines, Pencina said. We anticipated that the impact would be age-dependent, but not to the degree observed. The changes for both men and women in the older age groups were huge compared to those between the ages of 40 and 60.
Of the 12.8 million additional U.S. adults recommended for statin use under the new guidelines, 10.4 million would be prescribed the drugs for preventive care. Of those preventive users, 8.3 million would be older than 60.
The analysis also projects that 1.6 million adults previously eligible for statins under the old guidelines would no longer be candidates under the new standards. This group included primarily younger adults with elevated cholesterol but low 10-year risk of cardiovascular disease.
Pencina said an important limitation of the study is the necessary assumption that the new guidelines would be followed to the letter, when in fact people may be recommended for statins but decline to start the therapy.
Recommendations are just that recommendations, Pencina said. These guidelines correctly call for a thorough discussion between the doctor and patient about the risks and benefits of statins. Its not like everybody who meets the guidelines should all of a sudden go on statins.