Statin Treatment of Diabetic Patients in Utah Medicaid | Categories Utah Women and Cardiovascular Disease | DOI: 10.26054/0KXA0YFH3T

Background

There is strong evidence supporting the benefit of statin use in diabetic dyslipidemia for the prevention and treatment of cardiovascular disease (CVD). [1] The Adult Treatment Panel (ATP III) guidelines, an evidence-based report authored by the National Cholesterol Education Program, recommend that statin therapy be initiated in diabetic patients without regard to baseline blood cholesterol in all patients over the age of 40.[2]

Diabetic women, in particular, are at high risk of developing CVD. It has been documented that, in women, diabetes is associated with a worsening of dyslipidemia,[3] which is a significant contributor to CVD.[4] Diabetic women have a significantly higher rate of death due to CVD than nondiabetic women,[5] and a significantly higher CVD risk than diabetic men.[3]

In this study we characterized the proportion of diabetic Utah Medicaid recipients that were receiving statin treatment as recommended by American Dietetic Association (ADA) guidelines. We also compared the proportions of men and women receiving this preventive treatment.

Methods

All patients age 40 and above receiving benefits under Utah Medicaid between January 1, 2005 and September 30, 2006 were included if they were diagnosed (as defined by the 9th revision of the International Classification of Diseases [ICD-9]) or treated for diabetes (identified by First DataBank Specific Therapeutic Category codes). The proportion of women or men who received at least one prescription for a statin during the study period was determined by using pharmacy claims data.

Medication possession ratios (MPRs) were calculated for those patients who were covered throughout the whole study period as an indicator for adherence to the statin therapy. The MPR reflects the percentage of days the patients had statins available in relation to the entire study period.

Results

A total of 4416 females and 2017 males over the age of 40 were identified as having diabetes (see Figure 1). Of these, 68.6% of the diabetic patients were female. This proportion is similar to the gender distribution in the overall Utah Medicaid prescription claims database (67% female, 33% male).

Figure 1. Number of female or male diabetic patients over 40 covered by Utah Medicaid receiving prescriptions for statins.

Approximately half of the diabetic patients received statin treatment as recommended by ADA guidelines. There was no difference in the percentage of male or female diabetics receiving statins (see Figure 2).

Figure 2. Percentage of female or male diabetic patients over 40 covered by Utah Medicaid receiving prescriptions for statins

The overall medication possession rate in the patients who have been continuously eligible for Medicaid coverage and received statin during the study period (2223 women, 1015 men) was 85.9% for women and 88% for men. The proportions of patients with an MPR less than 0.5 were 19.4% of women and 15% of men.

Summary

Only half of the diabetic women over 40 covered by Utah Medicaid received preventive treatment with a statin. Those who received prescriptions for statins showed relatively high adherence as measured by MPR. In this study, no differences were observed between the diabetes prevalence and statin treatment ratio of male or female diabetic patients.

Figure 3. Medication possession rates for male or female patients with continuous Medicaid eligibility for
prescription drugs throughout the study period.

References

  1. Collins et al. MRC/BHF heart protection study of cholesterol-lowering with simvastatin in 5963 people with diabetes: a randomised placebo-controlled trial. Lancet 2003;361:2005–16.
  2. Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III). JAMA. 2001; 285:2486-97. [PMID: 11368702].
  3. Manson, Spelsberg. Risk modification in the diabetic patient. In: Manson et al., eds. Prevention of Myocardial Infarction. New York, NY: Oxford University Press; 1996:241–273.
  4. Arshag. Cardivascular disease in type 2 diabetes mellitus, current management guidelines. Arch Intern Med. 2003;163:33-40.
  5. Steinberg et al. Type II diabetes abrogates sex differences in endothelial function in premenopausal women. Circulation. 2000;101:2040-6. [PMID: 10790344]

Anke-Peggy Holtorf, PhD, MBA

Pharmacotherapy Outcomes Research Center,
Salt Lake City, UT