Coronary heart disease is the leading cause if death in the United States. But thanks to recently developed cholesterol lowering medications known as statins, many people can significantly reduce their risk of developing or dying from heart disease.

Although some people can stop taking statins if they are able to achieve healthier cholesterol levels through diet and exercise, most people who start statins must take them for life. Additionally, although both people who have a history of heart disease and those who simply have high cholesterol are regularly prescribed statins, it is the higher risk group—those with a history of heart disease—who stand to benefit the most from taking them. So does compliance with statin therapy between these two groups differ? Or are there other factors that affect adherence?

A new study in the June 2004 Journal of General Internal Medicine set out to answer these questions and found that adherence rates did not differ between the two groups: nearly half of all people in both groups stopped taking the medications temporarily or altogether. What’s more, the higher their copayments, the more likely they were to stop taking the medications.

About the Study

This study included 4,802 adults who were enrolled in a mid-western managed care organization and filled two or more statin prescriptions between January 1998 and November 2001.

The researchers categorized participants into two groups based on whether they were taking the statins due to a documented history of heart disease or major risk factor such as diabetes (secondary prevention) or to lower their cholesterol in the absence of known heart disease or other major risk factor (primary prevention). They then measured rates of nonadherance and discontinuation of therapy in the two groups. The researchers also looked at modifiable factors that may have influenced medication adherence.

The Findings

The researchers identified 2,258 (47%) individuals as taking statins for secondary prevention, and 2,544 (53%) as taking statins for primary prevention. Interestingly, participants in both groups were equally likely to temporarily discontinue their statin therapy (defined as not having enough pills for one or more days, out of ten days), although primary prevention participants were more likely to completely discontinue the statin therapy.

Perhaps not surprisingly was the impact of copayments. The greater the copayment the more likely a participant was to be non-adherent: 76% of participants with a $20 or greater monthly copayment were non-adherent compared to 50% of those who paid less than $10. Also, compared to participants who had a monthly co-payment under $10, those who paid between $10 and $20 were about 1.5 times more likely to either lapse on their medication or discontinue it altogether. While those who paid $20 or more were 3 times as likely to lapse on their medication and 4 times as likely to discontinue it.

How Does This Affect You?

This study suggests that more people are discontinuing their statin medications than previously reported, which is a concern given the significant benefits that statins can bring, especially for people who already have heart disease. And it shows that being diagnosed with heart disease isn’t always enough of an incentive for people to adhere to their prescription. It also highlights the direct relationship between monthly copayments and statin use—a finding that is consistent with another recently released study, which found that doubling copayments reduced the use of nonessential and essential medications.

Aside from the out-of-pocket expense, another reason why it may be tempting discontinue statins, is that they don’t cause any obviously noticeable changes. But while you may not feel any different, a simple blood test will show the improvements that the statin medication is making on your cholesterol levels. And in fact, the researchers in this study found that the more often a participant saw their cardiologist or had their cholesterol level tested, the more likely they were to stick with their medication. Physicians should therefore encourage their patients to come in for regular follow-up visits—both to check cholesterol levels and reinforce the importance of taking the medication on a daily basis.

Of all the medications and dietary supplements that have been promoted to reduce the risk of chronic disease or death, only a handful have consistently been shown to be effective. Statins fall into this group, particularly for people with known heart disease and/or diabetes. Committing yourself to taking this medication, despite its cost and lack of immediate and obvious benefits, is clearly worth it.