Socioeconomic Factors Associated With Glycemic Measurement and Poor HbA1c Control in People With Type 2 Diabetes: The Global DISCOVER Study

Abstract

DISCOVER is a 3-year observational study program of 15,983 people with type 2 diabetes initiating second-line glucose-lowering therapy in 38 countries. We investigated the association between socioeconomic status and both the availability of a baseline glycated hemoglobin (HbA1c) measurement and poor glycemic control (HbA1c level ≥ 9.0%) in participants enrolled in DISCOVER. Factors associated with a lack of baseline HbA1c measurement or an HbA1c level ≥ 9.0% were assessed using three-level hierarchical logistic models. Overall, 19.1% of participants did not have a baseline HbA1c measurement recorded. Lower-middle country income (vs. high) and primary/no formal education (vs. university education) were independently associated with a reduced likelihood of having a baseline HbA1c measurement (odds ratio [95% confidence interval]: 0.11 [0.03-0.49] and 0.81 [0.66-0.98], respectively. Of the participants with an available HbA1c measurement, 26.9% had an HbA1c level ≥ 9.0%; 68.7% of these individuals were from lower- or upper-middle-income countries. Factors associated with an increased likelihood of poor glycemic control included low country income, treatment at a site with public and/or governmental funding (vs. private funding) and having public or no health insurance (vs. private). A substantial proportion of DISCOVER participants did not have an HbA1c measurement; more than one-quarter of these participants had poorly controlled type 2 diabetes. Both individual- and country-level socioeconomic factors are associated with the quality of care regarding glycemic control. Awareness of these factors could help improve the management of patients with type 2 diabetes.

Keywords: glucose-lowering drug; glycemic control; observational study; socioeconomic factors; type 2 diabetes.

Figure 1

Factors associated with a lack of HbA1c measurements in patients enrolled in the DISCOVER study at baseline. ^aORs were calculated using three-level hierarchical models, with patients nested in sites and sites nested in countries and were adjusted for all variables in the figure. ^bEach R ² was calculated when the corresponding variable was removed from the model. The lower the resulting R ² value, the more important the removed variable was to the fit of the model. ^cCountries were categorized by 2015 gross national income per capita into lower-middle-income (US$1,005–3,955), upper-middle-income (US$3,956–12,235) and high-income (≥ US$12,236) countries. ^dPublic or governmental, or mixed, funding. ^ePublic, mixed or none. CI, confidence interval; HbA1c, glycated hemoglobin; OR, odds ratio; PCP, primary care physician.

Figure 2

Factors associated with having an HbA1c level ≥ 9.0% among DISCOVER study patients initiating a second-line glucose-lowering therapy. ^aORs were calculated using three-level hierarchical models, with patients nested in sites and sites nested in countries and were adjusted for all variables in the figure. ^bEach R ² was calculated when the corresponding variable was removed from the model. The lower the resulting R ² value, the more important the removed variable was to the fit of the model. ^cCountries were categorized by 2015 gross national income per capita into lower-middle-income (US$1,005–3,955), upper-middle-income (US$3,956–12,235) and high-income (≥ US$12,236) countries. ^dPublic or governmental, or mixed, funding. ^ePublic, mixed or none. CI, confidence interval; HbA1c, glycated hemoglobin; OR, odds ratio; PCP, primary care physician.