Medical expenditures can be controlled by improving patient adherence to medications. Various interventions, such as disease state management programs and medication therapy management (MTM) programs, have been initiated in an attempt to improve adherence to medications. One such program, Lucas County MTM program is sponsored by an employer group and provides services to Lucas County employees diagnosed with diabetes, hypertension, and hyperlipidemia.
The purpose of this study was to evaluate patient adherence to chronic disease medications and to determine the effect of adherence on the clinical outcomes of patients enrolled in Toledo Lucas County MTM program.
This was a retrospective, longitudinal study. Data was obtained for 272 patients from The Pharmacy Counter prescription database. Medication adherence was measured using Medication Possession Ratio (MPR). Pearson correlation was used to determine the relationship between medication adherence and desired clinical outcomes. Multiple linear regression was used to determine if medication adherence is a predictor of clinical outcomes. Data analysis was performed using SPSS version16.0 and Microsoft Excel.
Pearson correlation results indicated that MPR to diabetic medications was significantly correlated with age (r=0.387, p=0.000) and gender (r=-0.167, p=0.021). Further, age was significantly correlated with gender (r=-0.148, p=.042) and number of diseases (r=0.278, p=0.000) among diabetic patients. However, there were no significant predictors of change in A1c among diabetic patients. Among hypertension patients, change in systolic blood pressure was significantly correlated with change in diastolic blood pressure (r=0.553, p=0.000), gender (r=0.134 p=0.024), co-pay (r=0.118, p=0.048), and number of diseases (r=-0.132, p=0.026). Further, change in diastolic blood pressure was significantly correlated with MPR (r=-0.178, p=0.003). MPR was also found to be significantly correlated with gender (r=-0.138, p=0.020, co-pay (r=0.141, p=0.018), and number of diseases (r=0.139, p=0.019). Regression model for hypertension patients indicated that number of diseases (β = -0.130, p = 0.01), and change in diastolic blood pressure (β = 0.550, p = 0.000) were significant predictors of change in systolic blood pressure. Further, MPR (β = -0.151, p = 0.003) and change in systolic blood pressure (β = 0.552, p = 0.000) were found to be significant predictors of change in diastolic blood pressure.
Thus, patients enrolled in the Lucas County MTM program showed high average adherence to hypertension medications. This study also identified predictors of clinical outcomes associated with diabetes and hypertension.