Diabetes Numeracy

An overlooked factor in understanding racial disparities in glycemic control

  1. Chandra Y. Osborn, PHD, MPH1,
  2. Kerri Cavanaugh, MD, MHS1,
  3. Kenneth A. Wallston, PHD1,
  4. Richard O. White, MD2 and
  5. Russell L. Rothman, MD, MPP1
  1. 1Vanderbilt University, Nashville, Tennessee;
  2. 2Meharry Medical College, Nashville, Tennessee.
  1. Corresponding author: Chandra Y. Osborn, chandra.osborn{at}


OBJECTIVE Understanding the reasons and eliminating the pervasive health disparities in diabetes is a major research, clinical, and health policy goal. We examined whether health literacy, general numeracy, and diabetes-related numeracy explain the association between African American race and poor glycemic control (A1C) in patients with diabetes.

RESEARCH DESIGN AND METHODS Adults with type 2 diabetes (n = 383) were enrolled in a cross-sectional study at primary care and diabetes clinics at three medical centers. Data collected included the following: self-reported race, health literacy, general numeracy, diabetes-related numeracy, A1C, and sociodemographic factors. A series of structural equation models were estimated to explore the interrelations between variables and test for mediation.

RESULTS In model 1, younger age (r = −0.21, P < 0.001), insulin use (r = 0.27, P < 0.001), greater years with diabetes (r = 0.16, P < 0.01), and African American race (r = 0.12, P < 0.01) were all associated with poorer glycemic control. In model 2, diabetes-related numeracy emerged as a strong predictor of A1C (r = −0.46, P < 0.001), reducing the association between African American and poor glycemic control to nonsignificance (r = 0.10, NS). In model 3, African American race and older age were associated with lower diabetes-related numeracy; younger age, insulin use, more years with diabetes, and lower diabetes-related numeracy were associated with poor glycemic control.

CONCLUSIONS Diabetes-related numeracy reduced the explanatory power of African American race, such that low diabetes-related numeracy, not African American race, was significantly related to poor glycemic control. Interventions that address numeracy could help to reduce racial disparities in diabetes.


  • The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

  • See accompanying editorial, p. 1746.

    • Received March 8, 2009.
    • Accepted April 23, 2009.
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This Article

  1. Diabetes Care vol. 32 no. 9 1614-1619
  1. All Versions of this Article:
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