Defining the Role of Medication Adherence in Poor Glycemic Control among a General Adult Population with Diabetes

Abstract

AimsThis study assesses the attributable impact of adherence to oral glucose medications as a risk factor for poor glycemic control in population subgroups of a large general population, using an objective medication adherence measure.MethodsUsing electronic health records data, adherence to diabetes medications over a two-year period was calculated by prescription-based Medication Possession Ratios for adults with diabetes diagnosed before January 1, 2010. Glycemic control was determined by the HbA1c test closest to the last drug prescription during 2010–2012. Poor control was defined as HbA1c>75 mmol/mol (9.0%). Medication adherence was categorized as “good” (>80%), “moderate” (50–80%), or “poor” (<50%). Logistic regression models assessed the role medication adherence plays in the association between disease duration, age, and poor glycemic control. We calculated the change in the attributable fraction of glucose control if the non-adherent diabetic medication population would become adherent by age-groups.ResultsAmong 228,846 diabetes patients treated by oral antiglycemic medication, 46.4% had good, 28.8% had moderate, and 24.8% had poor adherence. Good adherence rates increased with increasing disease duration, while glycemic control became worse. There was a strong inverse association between adherence level and poor control (OR = 2.50; CI = 2.43–2.58), and adherence was a significant mediator between age and poor control.ConclusionsA large portion of the diabetes population is reported to have poor adherence to oral diabetes medications, which is strongly associated with poor glycemic control in all disease durations. While poor adherence does not mediate the poorer glycemic control seen in patients with longer-standing disease, it is a significant mediator of poor glycemic control among younger diabetes patients. A greater fraction of poorly controlled younger patients, compared to older patients, could be prevented if at least 80% adherence to their medications was achieved. Therefore, our results suggest that interventions to improve adherence should focus on this younger sub-group.

Psychosocial Care for People With Diabetes: A Position Statement of the American Diabetes Association

“…While following treatment regimens consistently improves A1C (9–12), the impact is modest. Multiple factors other than patient behavior affect diabetes treatment outcomes, including adequacy of medical management, duration of diabetes, weight gain, and other health-related (e.g., comorbid illness and concomitant medication) and social-structural factors (e.g., poverty, access to care, health insurance coverage) (13–16).…”

Risk factors for development and progression of diabetic retinopathy in Dutch patients with type 1 diabetes mellitus

“…High risk was defined as HbA1c = 74 mmol/mol, total cholesterol = 6.2 mmol/l and HDL = 1.0 mmol/mol, HbA1c variability = 9.1 and age of onset of T1DM = 30 years (DCCT, 1993, National Institutes of Health, 2001; Feldman et al. 2014). …”

Psychosocial factors in medication adherence and diabetes self-management: Implications for research and practice.

“…Non-adherence to recommendations can be unintentional or purposeful, reflecting patient decision-making that weighs anticipated treatment-related benefits and costs to health and quality of life (DiMatteo, 2004). Sub-optimal diabetes self-management is clearly associated with worse glycemic control (e.g., Feldman et al, 2014; Hood, Peterson, Rohan, & Drotar, 2009; Schectman, Nadkarni, & Voss, 2002) and increased risk for hospitalization, complications and mortality (e.g., Cho et al, 2011; Currie et al, 2012; Ho et al, 2006; Kuo et al, 2003). Thus, the consequences of poor diabetes self-management can be severe.…”