The strongest correlate of high-intensity statin use after myocardial infarction (MI) is geographic region, with patients in New England being most likely to be treated with high-intensity statins, according to study results published in JAMA Cardiology. These differences lead to large treatment disparities.

This retrospective cohort analysis of Medicare enrollment and administrative claims data evaluated the relative strength of hospital, geographic region, and patient characteristics with use of high-intensity statins after MI in patients age ≥66 years hospitalized between January 1, 2011 and June 30, 2015. Medicare data were used to abstract beneficiary characteristics, 2014 American Hospital Association Survey and Hospital Compare quality metrics were used to obtain hospital characteristics, and the US Census was used to define 9 regions in the United States.

Statin claim intensity after hospital discharge was characterized as high (atorvastatin calcium 40-80 mg or rosuvastatin calcium 20-40 mg) vs low to moderate. Poisson distribution mixed models were used to examine associations of geographic region and hospital and beneficiary characteristics with use of high-intensity statins after MI. Two-sided P <.05 was the cutoff for statistical significance.

Among 139,643 Medicare beneficiaries (mean age, 76.7±7.5 years; 69,675 women [49.9%] and 69,968 men [50.1%]), the overall use of high-intensity statins increased to 55.6% in 2015 from 23.4% in 2011, with treatment gaps persisting across regions.

In models that considered geographic region and hospital and beneficiary characteristics, the strongest correlate of high-intensity statin use was region, with use being 66% higher in New England (73.5% use) compared with the West South Central region, where use was 40.6% (risk ratio [RR] 1.66; 95% CI, 1.47-1.87).

Greater use of high-intensity statins was also linked with men (RR 1.1; 95% CI, 1.07-1.13), medical school affiliation (RR 1.11; 95% CI, 1.05-1.17), patient receipt of a stent (RR 1.35; 95% CI, 1.31-1.39), and hospital size of >500 beds (RR 1.15; 95% CI, 1.07-1.23).

High-intensity statin use was also negatively associated with younger patient age (RR 0.87; 95% CI, 0.84-0.89), lack of prior coronary heart disease (RR 0.93; 95% CI, 0.9-0.96) and prior heart failure (RR 0.95; 95% CI, 0.91-1), and for-profit hospital ownership vs not-for-profit hospital ownership (RR 0.86; 95% CI, 0.79-0.92).

Strengths of the study include the large sample size and high generalizability of using Medicare claims data. Conversely, claims data could not reveal whether statin choices were based on factors such as prior statin experience and lipid profiles. Nonetheless, these kinds of clinical characteristics are not likely to vary enough by region to explain the large differences seen in analyses.

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The study investigators concluded, “Among Medicare beneficiaries, geographic region, rather than patient and hospital characteristics, was the most closely associated with high-intensity statin use after MI, leading to large treatment disparities. Reasons for these persistent regional disparities are poorly understood and require further research and intervention.”

Disclosure: This clinical trial was supported by Amgen, Inc. Please see the original reference for a full list of authors’ disclosures.

Reference

Bittner V, Colantonio LD, Dai Y, et al. Association of region and hospital and patient characteristics with use of high-intensity statins after myocardial infarction among Medicare beneficiaries [published online July 24, 2019]. JAMA Cardiol. doi:10.1001/jamacardio.2019.2481