Adherence to oral antidiabetic medications in the pediatric population with type 2 diabetes: a retrospective database analysis

Abstract

Background: Little has been done in assessing adherence to oral antidiabetic (OAD) medications in the pediatric population presenting with type 2 diabetes. This study provided information on adherence rates in the Texas Medicaid pediatric population with type 2 diabetes, which is rare in the literature. The knowledge of adherence rates in the pediatric population with type 2 diabetes might help improve the care given to pediatric patients with type 2 diabetes.

Objective: To describe OAD medication use, and assess trends in medication adherence and persistence among Texas pediatric Medicaid patients.

Methods: Texas Medicaid prescription claims data of patients between 10 and 18 years of age, with at least 2 prescriptions of the same OAD medication from January 1, 2006 to December 31, 2009, were analyzed. Adherence was assessed using the medication possession ratio (MPR) as a proxy.

Results: A total of 3109 patients met the study's inclusion criteria. The mean (SD) age of the 3109 eligible patients was 14.2 (2.3) years; 60% were Hispanics, 14% were blacks, 13% were whites, and another 13% were other minority races; 67% of the population were females; and 91% were on metformin of the 6 OAD medications included in the study The overall mean (SD) MPR for patients was 44.69% (27.06%). Adherence differed by gender (P < 0.0001), race (P < 0.0001), and age category (P < 0.0001). Males had higher mean (SD) MPR (47.47% [27.42%]) compared with females (43.29% [26.78%]). Mean MPR for whites (50.04% [29.65%]) was significantly higher compared with blacks (44.24% [26.16%]) and Hispanics (42.50% [26.10%]). Patients ≤12 years of age had significantly higher mean MPR (48.82% [27.37%]) compared with those in older age categories. Logistic regression analysis suggested that age was significantly related (odds ratio [OR] = 0.91; 95% CI, 0.87-0.95) to being adherent (MPR ≥80%). Males were 25% (OR = 1.25; 95% CI, 1.02-1.53; P = 0.034) more likely to be adherent (MPR ≥80%) compared with females, and whites were twice as likely to be adherent (MPR ≥80%) compared with Hispanics (OR = 2.02; 95% CI, 1.54-2.66; P = 0.0012). Overall, mean (SD) days to nonpersistence was 108 (86) days. Persistence was significantly and negatively associated with age (P < 0.0001). White race was significantly related to longer persistence.

Conclusion: Adherence and persistence to OAD medications in the selected Texas Medicaid pediatric population between 10 and 18 years was generally suboptimal, especially in adolescents.