PATIENT ACTIVATION AND MEDICATION ADHERENCE AMONG MEDICARE BENEFICIARIES WITH TYPE 2 DIABETES

Abstract

The objectives of this study were to assess patient activation levels, to assess association between sociodemographic characteristics and patient activation, to assess association between health status characteristics and patient activation, and to assess association between patient activation and medication adherence among Medicare beneficiaries with type 2 diabetes. A retrospective cohort study was conducted using data from the 2009 through 2013 Medicare Current Beneficiary Survey (MCBS). Patient activation was measured with the Patient Activation Supplement in the MCBS and was categorized as low, moderate, and high levels based on activation scores. Medication adherence was assessed with proportion of days covered (PDC) using Medicare Part D administrative records from the MCBS within a period of six months after measurement of patient activation. The sample included Medicare beneficiaries who completed the MCBS Patient Activation questionnaire, who were diagnosed with type 2 diabetes, and who were 18 or older. Beneficiaries were excluded if they responded “Not ascertained,” “Not Applicable,” “Don’t know” or “Refused” to more than 50 percent of the Patient Activation questions, did not have continuous Medicare Part A and Part D coverage throughout the assessment period, had less than two Medicare Part D claims for an antidiabetic medication throughout the assessment period, used insulin during the assessment period, resided in long-term care facilities, or had Alzheimer’s disease, dementia, mental retardation or mental disorder. All analyses were conducted in SAS 9.4 for Unix environment. An a priori alpha level of 0.05 was used to determine significance. Bivariate and multivariable weighted ordinal logistic regression were applied for assessing associations. A total of 571 individuals met sample selection criteria. The mean age was 72.4 years. Of the 571 persons in the sample, 27.5 percent were at low activation level, 38.7 percent were at moderate activation level, and 33.7 percent were at high activation level. Approximately three-fourths of the sample persons were adherent to antidiabetic medications. Low activation was more likely to be found in males, less educated patients, and patients without arrhythmia. Ex-smokers as compared to non-smokers and overweight patients as compared to those with healthy weight were less likely to report low activation. In multivariable logistic analysis adjusting for race, gender, osteoporosis, Charlson Comorbidity Index score, and number of prescribed medications, patient activation level was not significantly associated with medication adherence. Non-Whites and patients with a Charlson Comorbidity Index score of 1 as compared to those with a score of 0 were more likely to be non-adherent. A lower number of prescribed medications was associated with higher odds of non-adherence.