A large majority of patients with diabetes in the Veteran Affairs (VA) healthcare system are appropriately treated with statin therapy, research shows. Using a performance measure that credited appropriate clinical treatment, researchers report that 85% of veterans aged 50 to 75 years old were receiving appropriate management of their dyslipidemia.
The researchers also noted, however, that 14% of diabetic patients without ischemic heart disease were treated with high-dose statin therapy, a finding that suggests some of these patients may be potentially overtreated.
Dr. Ashley Beard, University of Michigan, Ann Arbor and colleagues reported that, "In our analysis, there was no evidence that the use of high-dose statins among those without ischemic heart disease correlated with cardiovascular risk." Furthermore, they stress that this rate of potential overtreatment "is likely conservative, because the evidence supporting use of high-dose statins is mixed," even in those with stable ischemic heart disease.
Dr. Eve Kerr, senior investigator (VA Ann Arbor Healthcare System, MI) said the standard way to measure the management of dyslipidemia in patients with diabetes is centered on an LDL cutoff value, the most frequently used being LDL-cholesterol levels of less than 100 mg/dL. "However, the evidence from most of the studies that have been done do not directly use a cutoff LDL value but test whether appropriate treatment is provided for patients," said Kerr. "And appropriate treatment, the treatment that has been found to be most effective in preventing cardiovascular events, is using moderate-dose statins."
The researchers developed a clinical action measurement for lipid management in patients with diabetes mellitus but without cardiovascular disease. The measure was designed to encourage appropriate treatment with moderate-dose statins of patients with diabetes mellitus in the VA system and included the following criteria: achieving the target threshold of LDL-cholesterol levels <100 mg/dL; treatment with moderate-dose statins when LDL cholesterol was >100 mg/dL; or starting, switching, or intensifying statin therapy if LDL cholesterol was >100 mg/dL. Moderate-dose statins were defined as drugs capable of yielding a 30% to 40% reduction in LDL cholesterol.
Dr. Kerr stated that, "So our approach is to really think about the appropriateness of treatment and less about meeting a target threshold." "We think a good performance measure motivates the right clinical action that will yield the best outcomes for our patients. In the past, these measures have just motivated us to get to an LDL-cholesterol level less than 100, regardless of how that was done or what medications were used. Some medications have not been shown to have any benefit, and some have shown, especially high-dose statins, to cause adverse effects."
Between 2010 and 2011, 964,818 active VA primary-care patients 18 years of age and older were identified with diabetes mellitus. Of these, 668,209 patients were between the ages of 50 and 75 years. For these older patients, 84.6% met the clinical action appropriateness measure, with 67.2% treated to a target <100 mg/dL, 7.5% with LDL-cholesterol levels >100 mg/dL treated with a moderate-dose statin, and 5.5% having therapy started, switched, or intensified. Of the entire cohort, 13.7% of patients were treated with a high-dose statin.
In addition, the researchers found that high-dose statins were not correlated with higher cardiovascular risk. For example, physicians were more likely to use high-dose statins in patients with lower cardiovascular risk, a paradoxical finding that didn’t make a lot of sense, said Kerr.
"We found that about 14% of patients with diabetes who did not have heart disease were on high-dose statins." "It suggests that at least some of those have the potential for overtreatment and that maybe they would be just fine on a moderate-dose statin." "Now, we’re not talking about this as a performance measure." "We’re calling it a marker of potential of overtreatment for quality-improvement purposes. If you have a lot of your diabetic patients without heart disease on high-dose statins, as a physician I would want to look at that. I would want to know what patients would do just fine on a lower-dose statin to minimize their risk of significant side effects."
Published online December 11, 2012 in Circulation: Cardiovascular Quality Outcomes