Health literacy in patients with Type 2 Diabetes Mellitus: A systematic review

To map studies that assessed the Health Literacy (HL) of people with diabetes, provide a global view of this level of literacy, and investigate its relationship between glycemic target and complication rates.

The authors conducted a systematic and sensitive search across the following electronic databases, including publications from inception to August 2021: Embase, LILACS, Cochrane Library, and MEDLINE. Any type of study that assessed any clinical question related to HL in adults with Type 2 Diabetes Mellitus (T2DM) was selected. In the study, participants had to fill out questionnaires that assessed their level of HL with one of the following tools: TOFHLA, S-TOFHLA, NVS, and REALM.

A total of 57 records were included in this review. The prevalence of inadequate HL ranged between 4.7% and 71.7%. Twenty-six studies evaluated the association between HL and glycemic target, and four investigated the association between HL rates and diabetes complications. Ten of them found an inverse association between HL and glycated hemoglobin, suggesting that inadequate diabetic control was more frequent among patients with lower levels of HL.

This study found that, apparently, there is a direct relationship between the level of HL and disease control as well as an inverse relationship between HL and the risk of developing some complications. These findings could justify the routine assessment of HL among patients with T2DM, as well as the development of strategies to improve their levels.