Clinical and economic outcomes in medication-adherent and -nonadherent patients with type 2 diabetes mellitus in the Republic of Korea.

Abstract

BACKGROUND: The prevalence and social burden of type 2 diabetes mellitus (T2DM)

is increasing. Medication adherence is necessary for positive outcomes in

patients with T2DM. OBJECTIVE: This study evaluated the association between

medication adherence and clinical/economic outcomes in patients with T2DM in the

Republic of Korea over a 3-year period. METHODS: This study used data from the

Korean National Diabetes Program at 5 hospitals. Medication possession ratios of

>/=90% and <90% were used to define adherent and nonadherent groups,

respectively. The degree of glycemic control, changes in blood pressure and lipid

profiles, and health care costs were compared. RESULTS: Of the 608 patients, 472

were medication adherent and 136 were nonadherent. The adherent patients

displayed improved fasting blood glucose and hemoglobin A1c during the study.

Diastolic blood pressure and total cholesterol were lower at 36 months, and lower

low-density lipoprotein cholesterol was noted at baseline and 24 months. The

total health care costs were $1861, $2060, and $1924, respectively, versus $1617,

$1751, and $1602 during the 3-year study period for the adherent group versus the

nonadherent group, respectively (P = 0.316, 0.627, and 0.172, respectively),

whereas the outpatient drug costs were $1143, $1176, and $1162 in the adherent

group versus $925, $778, and $914 in the nonadherent group (P = 0.002, P < 0.001,

and P = 0.001). CONCLUSIONS: The adherent patients displayed better glycemic

control and lipid profiles. Medication-related expenses were higher in the

adherent group, but overall health care costs, including hospitalization costs,

were similar between the 2 groups.