Adherence to Oral Antidiabetic Medications in the Pediatric Population With Type 2 Diabetes: A Retrospective Database Analysis

Abstract

BackgroundLittle 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. ObjectiveTo describe OAD medication use, and assess trends in medication adherence and persistence among Texas pediatric Medicaid patients. MethodsTexas 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. ResultsA 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. ConclusionAdherence and persistence to OAD medications in the selected Texas Medicaid pediatric population between 10 and 18 years was generally suboptimal, especially in adolescents.