IMPACT OF MULTIPLE MEDICATION COMPLIANCE ON DISEASE BURDEN IN A CALIFORNIA MEDICAID POPULATION WITH COMORBID TYPE II DIABETES AND CARDIOVASCULAR DISEASE

Purpose: To investigate the association of multiple medication compliance with disease burden. 

Method: California Medicaid (MediCal) eligibility and administrative data (2002-2003) were used to identify patients ≥40 years of age with a diagnosis of type II diabetes concurrent with any combination of the following cardiovascular diseases (CVD): hypertension, coronary artery disease, and heart failure.  Patients were continuously eligible for MediCal coverage in 2004.  Medication compliance and healthcare utilization were evaluated in 2004.  Proportion of days covered ≥0.8 was used to evaluate medication compliance for both anti-diabetic and CVD medications.  Disease burden was defined as any emergency or inpatient visit.  Multivariable logistic regressions were used to assess the association of multiple medications compliance with disease burden in 2004.  Three dependent variables (diabetes-related, CVD-related, and all-cause burden) were assessed.  The covariates included patients’ demographic characteristics, race, MediCal and Medicare dually eligibility, severity of disease as measured by type of comorbid CVD and number of CVD classes drug fills, and comorbidities.  

Result: We identified 21,740 patients.  Mean (SD) age was 65.7 (11.3) years old, 64.8% of patients were female.  Only 18% of patients were compliant with both diabetes and CVD medications.  Approximately 3% of patients had diabetic-related burden, 4.6% had CVD-related burden, and 26.3% had all-cause disease burden.  When compared with patients who were compliant with both diabetes and CVD medications, the patients who did not fill appropriate medications for treating diabetes and CVD or were noncompliant with both medications were significantly associated with CVD-related burden (odd ratio [OR]=1.75, 95% confidence interval [CI]=1.43-2.13),  diabetes-related burden (OR=1.51, CI=1.16-1.97), and all-cause burden (OR=1.65, CI=1.48-1.84); those were compliant with only diabetes medication were significantly associated with all-cause burden (OR=1.33, CI=1.20-1.48).  Patients who were compliant with only CVD medication were significantly associated with CVD-related (OR=1.56, CI=1.21-2.02) or all-cause burden (OR=1.31, CI=1.12-1.53). 

Conclusion: Compliance with both diabetes and CVD medications in a MediCal population with comorbid type II diabetes and CVD was suboptimal.  Noncomplying with medications for treatment of diabetes and CVD was significantly associated with either diabetes-related, or CVD-related or all-cause burden.