CHRONIC DISEASES such as hypertension and diabetes require patient education to achieve adequate control and prevent adverse health outcomes. Patients with hypertension may need to understand how to properly take multiple medications and modify their lifestyle (eg, low salt diet, weight loss, or exercise) to achieve adequate blood pressure control.1 The intricacies of the diabetic diet, insulin injection, and home glucose level monitoring place even greater educational requirements on patients.2,3 Patient education also plays a critical role in facilitating patients' acceptance of their diagnosis and understanding behavioral changes required for active participation in treatment.4
Traditional patient education relies heavily on written material about disease processes, medical management, and self-care instructions. Despite the availability of extensive health education materials with relatively consistent content, many are written at too high a level for low-literate patients to comprehend essential points.5- 9 Thus, patients with inadequate literacy may not benefit from such educational efforts. This may explain why some patient education programs have been unsuccessful.10,11
This problem may be more common than many health care providers realize; reading skills are deficient in 46% to 51% of adult US citizens according to the National Adult Literacy Survey.12 We previously documented that 35.1% of English-speaking patients and 61.7% of Spanish-speaking patients seeking care at2 public hospitals lack literacy skills adequate to function in the health care settings.13 We and others showed that lower literacy skills also correlate with poorer self-reported health status.14,15 Because of their worse health, patients with poor literacy skills are likely to have even greater educational needs. However, the impact of literacy on patients' knowledge of their own illnesses and self-management skills has not been elucidated.
To examine the relationship between literacy and knowledge of chronic disease, we focused on patients with hypertension and diabetes. In addition to being prevalent, these chronic diseases require daily attention to self-care and have standard markers of disease control (levels of hemoglobin [Hb] A1c and blood pressure). In this study we measured the functional health literacy of patients with diabetes or hypertension and evaluated the relationship of patients' literacy levels to knowledge of their chronic disease and markers of disease control. Understanding the role of functional health literacy in disease management and patient education should enhance efforts to improve patients' knowledge of their disease and adherence to treatment plans.