• Clinical and economic impact of statin therapy compliance on hyperlipidemic patients with concomitant CHD risk factors

      Samant, Navendu Dinanath; Shaya, Fadia T. (2010)
      In cholesterol management, a common and widely used class of drug is 3-hydroxyl-3-methylglutaryl coenzyme A reductase inhibitor (statin). These drugs lower cholesterol by slowing down the production of cholesterol and by increasing the liver's ability to remove LDL cholesterol already in the blood. Statins are well tolerated, and serious side effects such as liver problems, muscle soreness, pain, and weakness are rare. Compliance to prescribed medication is an important component of appropriate pharmacotherapy. Maryland Medicaid managed care (MCO) data were used to examine risk factors of patient non-compliance to statin therapy and its impact on healthcare utilization and the risk of having a new cardiovascular event among patients with hyperlipidemia and one or more CHD risk factors. The sample included Maryland Medicaid MCO patients who were diagnosed with hyperlipidemia and an additional CHD risk factor and were statin drug users. The proportion of patients compliant to statin therapy was 38 percent. The average age of the sample was 50. Over half of the sample was African American (50.69 percent), the rest Caucasian (41.54 percent) and Others (7.77 percent). Results for predictors of statin therapy compliance indicated that age and race had a significant impact on compliance. Although statistically non-significant, compliance was higher among patients with higher Charlson Comorbidity Index (CCI) scores. The probability of being compliant to statin therapy increased with age. African Americans (odds ratio = 0.662, 95 percent CI = 0.580-0.756) and Other race (odds ratio = 0.689, 95 percent CI = 0.549-0.865) groups were less compliant to statin therapy than Caucasians. The cost model indicated that compliant patients did not differ in cardiovascular disease (CVD) related medical costs from semi-compliant or non-compliant patients. The results of the CV risk model indicated that patients who were compliant to statin therapy had lower risk of a cardiovascular event than patients not compliant to statins and the findings were statistically significant. In conclusion, the study did not find significant evidence to prove that compliant patients would have lower CVD related costs. Risk of CV event was lower in compliant patients and was statistically significant. The study was conducted from January 1, 2002 through June 31, 2005. Future studies could examine the impact of compliance over a longer period of time in the Medicaid population.
    • Medication Adherence, Cardiovascular Disease Hospitalizations, and Health Care Utilization among Medicaid Populations with Diabetes, Hypertension, and/or Hyperlipidemia

      Yan, Xia; Shaya, Fadia T. (2011)
      Few studies have been conducted that explore the impact of cardiovascular disease (CVD) hospitalizations on patient adherence to CVD drugs. Medicaid beneficiaries at high-risk for CVD, a vulnerable population, had not been a focus of prior studies in exploring the impact of patient adherence to cardioprotective drugs on health utilization. The study population was Maryland Medicaid beneficiaries with hypertension, hyperlipidemia, or diabetes. Adherence rates to antidiabetic (AD), antihypertensive (AH), or antihyperlipidemic (AL) drugs were measured in the 6-month pre-index and post-index periods. Patients with and without CVD hospitalization were matched on gender, race, age (±5 years), and pre-index adherence rate (±5%). Adherence rate to cardioprotective drugs among patients with a CVD event was measured in the 6-month, one-year, or two-year post-index periods. Patients with and without adherence to cardioprotective drugs were matched using propensity score matching. Conditional logistic regression analysis was conducted to explore the impact of CVD hospitalization on patient adherence to AD, AH, or AL drugs. The association of patient adherence to cardioprotective drugs with hospital utilization was explored using Cox regression analysis. Patients with CVD hospitalization were more likely than those without CVD hospitalization to be adherent to AD or AH drugs in the 6-month post-index period. Improved adherence to AD, AH, or AL drugs comparing the 6-month post-index to the 6-month pre-index period was more likely to be shown in patients with CVD hospitalization than in those without CVD hospitalization. A substantial proportion of patients were not adherent to AD, AH, or AL drugs during the 6-month post-CVD hospitalization period. Patients who were adherent to at least one cardioprotective drug were less likely than those who were not adherent to be associated with the risk of experiencing any all-cause hospitalizations, CVD-related hospitalizations, or CVD-related emergency room (ER) visits. Hospital-based education might provide an opportunity for patients to improve their awareness of the importance of medication adherence. Follow-up interviews by health professionals could help patients maintain adherence to medication after hospital discharge. Medicaid beneficiaries at high-risk for CVD are vulnerable, and improving adherence to cardioprotective drugs in this population might contribute to a reduction in hospital utilization.
    • Radiation Therapy for Breast Cancer: Cardiovascular Event Free Survival (EFS) and Costs

      Onwudiwe, Nneka; Mullins, C. Daniel (2012)
      PURPOSE To estimate the risk of cardiac injury/death associated with modern radiation in a population of women with different cardiovascular (CV) risk. PATIENTS AND METHODS The data used for this analysis are from the linked SEER-Medicare database. The study included women aged 66 years and older with stage 0 - III breast cancer diagnosed between 2000 and 2005. Women were retrospectively categorized into low, intermediate, or high risk groups based on the presence of certain clinical diagnosis. The risk for a hospitalization for a cardiac event/death was estimated using a multivariable Cox model. RESULTS The median follow-up time was 24 months. Among the 91,612 women with AJCC stage 0 - III breast cancer: 39,555 (43.2%) were treated with radiation therapy and 52,057 (56.8%) were not. Radiation-treated women were younger, were likely to have pre-existing cardiovascular disease, cardiovascular risk factors and more advanced stage at diagnosis (P < .001). The following baseline characteristics were significant predictors of an increased risk for the combined outcome: decreasing year of diagnosis, age at diagnosis, AJCC stage I - III, the number of comorbid conditions, and left-sided tumor. Chemotherapy did confer an elevated risk (HRs = 1.104 - 1.282; 95% CI, 1.062 - 1.431) for the combined outcome in all three cardiovascular (CV) risk groups. The effect of radiation in the first 6 months significantly increases the risk for the combined outcome in women categorized as high risk (HR= 1.510; 95% CI, 1.396 - 1.634) for a future cardiovascular event compared to those with an intermediate risk (HR= 1.415; 95% CI, 1.188 - 1.686) or low risk (HR= 1.027; 95% CI, 0.798 - 1.321) for a future cardiovascular event. CONCLUSION The adverse cardiac effects of radiation as delivered today may pose a greater risk for an event in high risk patients and may thus require the use of techniques that further minimize the heart from radiation exposure. Recognition of the adverse cardiac effects of radiation should not offset any potential reduced risk of cancer recurrence or death from cancer, but should decrease irradiated cardiac volume as much as possible.