Influence of patient literacy on the effectiveness of a primary care-based diabetes disease management program

Context Low literacy is an important barrier for patients with diabetes, but interventions to address low literacy have not been well examined. Objective To examine the role of literacy on the effectiveness of a comprehensive disease management program for patients with diabetes. Design, Setting, and Participants Analysis of the influence of literacy on glycemic control and systolic blood pressure using data from a randomized controlled trial (conducted from February 2001 through April 2003) of a comprehensive diabetes management program. Participants were 217 patients aged 18 years or older with type 2 diabetes and poor glycemic control (glycosylated hemoglobin [HbA(1c)] levels greater than or equal to8.0%) and presenting to a US academic general internal medicine practice. Interventions All communication to patients was individualized and delivered to enhance comprehension among patients with low literacy. Intervention patients received intensive disease management from a multidisciplinary team. Control patients received an initial management session and continued with usual care. Main Outcome Measures Achievement of goal HbA(1c) levels and systolic blood pressure at 12-month follow-up for control and intervention patients stratified by literacy status. Results Complete 12-month data were available for 193 patients (89%). Among patients with low literacy, intervention patients were more likely than control patients to achieve goal HbA(1c) levels (less than or equal to7.0%) (42% vs 15%, respectively; adjusted odds ratio [OR], 4.6; 95% confidence interval [CI], 1.3 to 17.2; P=.02). Patients with higher literacy had similar odds of achieving goal HbA(1c) levels regardless of intervention status (24% vs 23%; adjusted OR, 1.0; 95% CI, 0.4 to 2.5; P=38). Improvements in systolic blood pressure were similar by literacy status. Conclusions Literacy may be an important factor for predicting who will benefit from an intervention for diabetes management. A diabetes disease management program that addresses literacy may be particularly beneficial for patients with low literacy, and increasing access to such a program could help reduce health disparities.