Stephen J.LurieMD, PhD, Senior Editor
To the Editor: Dr Schillinger and colleagues1 found a correlation between poor health literacy and uncontrolled type 2 diabetes. However, we suspect that the correlation is even greater than this study suggests.
Several aspects of the study could falsely underestimate the effect of poor health literacy on diabetic control. First, individuals with the constellation of factors that are often associated with poor health literacy (eg, less education, ethnic minority background, low socioeconomic status) may be less likely to seek medical care and thus to have less access to adequate longitudinal care. We assume that poor access to medical care can further increase the likelihood of uncontrolled diabetes. If this is the case, then the 261 patients not included in this study because they did not visit their physicians during study enrollment probably represent a significant number of patients with "poor health literacy," who are at a higher risk for poorly controlled type 2 diabetes than their counterparts who were included in the study (because they made a primary care visit).
Zimmerman T, Shenenberger DW. Health Literacy and Diabetic Control. JAMA. 2002;288(21):2688. doi:10.1001/jama.288.21.2688-JLT1204-4-2