Noel E. Wilkin

Predictors of Medication Nonadherence Among Patients With Diabetes in Medicare Part D Programs: A Retrospective Cohort Study

OBJECTIVES This study examined the prevalence of nonadherence with oral hypoglycemic agents, antihypertensive drugs (angiotensin-converting enzyme inhibitors [ACEIs] and angiotensin II receptor blockers [ARBs]), and statin medications among Medicare Part D enrollees with diabetes and analyzed the potential demographic and clinical factors that predict medication nonadherence. METHODS This was a retrospective cohort study of Medicare Part D enrollees with diabetes from 6 states (Alabama, California, Florida, Mississippi, New York, and Ohio). Adherence was calculated as the proportion of days covered (PDC; number of days with medication on hand/number of days in the specified time interval). A PDC was derived for each of the 3 categories of medications for patients who had at least 1 claim for the same class of medication. A comorbidity measure was created for each beneficiary using the Deyo-adapted Charlson Comorbidity Index (CCI). Associations between nonadherence and patient characteristics including age, sex, race/ethnicity, and Deyo-adapted CCI were examined. Logistic regression models were constructed to identify predictors of nonadherence. RESULTS The study included 1,888,682 patients with diabetes. The mean (SD) age was 71.6 (11.6) years, and 59.5% (1,123,220/1,888,682) were female. A total of 66.4% (1,254,538/1,888,682) were white, 16.3% (308,158/1,888,682) were black, and 7.8% (147,498/1,888,682) were Hispanic. Estimated rates of non-adherence for oral hypoglycemic agents, ACEIs/ARBs, and statins were 35.1% (386,666/1,101,533), 41.8% (449,561/1,075,285), and 46.4% (447,106/962,877), respectively. In unadjusted analyses, patients aged <65 years, women, black or Hispanic patients, and patients with higher Deyo-adapted CCI were more likely to be nonadherent to all 3 classes of medications. The results were consistent in multivariate analyses, and all results were statistically significant at P < 0.001. CONCLUSIONS In this study of Medicare Part D enrollees with diabetes, patients aged <65 years, women, black or Hispanic patients, and those with higher comorbidity scores were more likely to be nonadherent to medications. Interventions should be developed to improve medication adherence among these subgroups so that patients can achieve the full benefits of prescribed pharmacologic therapies.

Instrument to measure psychological contract violation in pharmacy students.

Objectives. To adapt and evaluate an instrument that measures perceived psychological contract violations in pharmacy students by schools and colleges of pharmacy. Design. A psychological contract violations measure was developed from existing literature and the 1997 ACPE Guidelines and pilot-tested with second-year pharmacy students at 2 schools of pharmacy. A revised measure then was administered to second-year pharmacy students at 6 schools of pharmacy. Using a 5-point Likert-type scale, participants were asked to indicate the level of obligations they received compared to what was promised by the school of pharmacy. Results. Exploratory factor analysis on the psychological contract violations measure was conducted using principal components analysis resulting in 7 factors, which led to a revised measure with 26 items. Using a sample of 339 students, the proposed 7-factor measurement model was tested using confirmatory factor analysis. In general, the results supported the hypothesized model. The final 23-item scale demonstrated both reliability and validity. Some students perceived certain aspects of the psychological contract that exists with their school of pharmacy were being violated. Conclusion. The psychological contract violations measure may serve as a valuable tool in helping to identify areas where their students believe that schools/colleges of pharmacy have not fulfilled promised obligations.

Nonadherence to angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blockers among high-risk patients with diabetes in Medicare Part D programs

OBJECTIVES To identify predictors of nonadherence to angiotensin-converting enzyme inhibitors (ACEIs) and/or angiotensin II receptor blockers (ARBs) and to assess the association between nonadherence to ACEIs/ARBs and potentially avoidable hospitalizations (PAHs) among elderly high-risk patients with diabetes. METHODS Medicare Part D enrollees from six states who had diabetes and coexisting hypertension and/or renal disease, were aged 65 years or older, and who had filled at least one prescription for ACEIs/ARBs in the first 6 months of 2006 were included in this retrospective cohort study. The primary outcomes of interests were patient nonadherence to ACEI/ARB therapy, which was defined as a proportion of days covered (PDC) less than 0.8 and PAH for diabetes during the patient follow-up period (July 1, 2006, to March 31, 2007). RESULTS A total of 599,141 patients (mean [+/-SD] age 75.6 +/-7.3 years, 66% women, 63% white, 15% black, and 9% Hispanic) were included. Among them, 46% were nonadherent to ACEI/ARB therapy and 6.3% had a PAH during the follow-up period. In multivariate logistic regressions, patients with diabetes and both hypertension and renal disease and patients with diabetes and renal disease only were 24% and 15% more likely, respectively, to be nonadherent to ACEI/ARB therapy compared with patients with diabetes and hypertension. Black and Hispanic patients were also more likely to be nonadherent to ACEI/ARB therapy. Nonadherence to ACEI/ARB therapy was associated with a 5% increase in the likelihood of PAH. CONCLUSION Adherence to ACEI/ARB therapy is suboptimal among elderly high-risk patients with diabetes enrolled in Medicare Part D programs from six states, and nonadherence to ACEIs/ARBs is associated with a slightly increased risk for PAH.

High-risk Diabetic Patients in Medicare Part D Programs: Are They Getting the Recommended ACEI/ARB Therapy?

BACKGROUNDDiabetes patients with hypertension and/or renal disease are at an increased risk of cardiovascular morbidity and mortality. Clinical evidence suggests that the use of ACEI/ARB for these patients improves patient outcomes.OBJECTIVETo describe ACEI/ARB utilization among high-risk patients with diabetes and to identify patient characteristics that predict suboptimal utilization of ACEI/ARB.DESIGNA retrospective cohort study.PATIENTSDiabetic patients with coexisting hypertension and/or renal disease with continuous Medicare coverage from October 1, 2005 through June 30, 2006 in six states (Alabama, California, Florida, Mississippi, New York, and Ohio).INTERVENTIONS AND MEASUREMENTSAny ACEI/ARB use during the first 6 months of 2006.RESULTSA total of 1,250,466 Medicare Part D enrollees met our inclusion criteria. ACEI/ARB utilization rates were 63%, 58.3%, and 43.1% among diabetic patients with hypertension and renal disease, hypertension without renal disease, and renal involvement without hypertension, respectively. After adjusting for all other characteristics studied, patients in the hypertension only (OR 0.83; 95% CI: 0.82–0.84) and renal disease only (OR: 0.48; 95% CI: 0.46–0.50) risk groups were less likely to use ACEI/ARB compared to diabetes patients with both hypertension and renal disease. Several demographics, including male gender, age older than 65, and white race, were all predictors of suboptimal ACEI/ARB use. Results from state-specific analyses are consistent with those for all six states.CONCLUSIONIn this cohort, less than 60% of high-risk patients with diabetes were receiving the recommended ACEI/ARB therapy. Several patient demographic and clinical characteristics are strongly associated with suboptimal ACEI/ARB use.