LitKDM2 study: the impact of health Literacy and knowledge about the disease on the metabolic control of type 2 diabetes mellitus

Aims: Diabetes mellitus (DM) is a common chronic disease with serious individual and socioeconomic consequences. Low health literacy (HL) has been associated with higher morbimortality. Health knowledge about DM (HK-DM) may also influence individual health. We aimed to assess HL and HK-DM in patients with type 2 DM and their associations with metabolic control.

Methods: Our sample comprised 194 diabetic patients from a primary care health centre. We collected clinical and demographic data and applied two validated questionnaires, the Newest Vital Sign (NST) and Diabetes Knowledge Test (DKT), to assess HL and HK-DM, respectively. Metabolic control was defined as HbA1c < 7.0%. Participants were classified according to the NST as having "high likelihood of limited HL" (HLL-HL), "possibility of limited HL" (PL-HL), or "adequate HL" (A-HL) and by the DKT as having "low", "average" and "good" HK. Statistical analysis included logistic regression models, using p < 0.05 as a cut-off for statistical significance.

Results: Overall, 72.7 and 34.7% of participants had HLL-HL and low HK-DM, respectively. A-HL (OR = 6.02; 95% CI: 1.691-21.450) and PL-HL (OR = 4.78; 95% CI: 1.350-16.899) were significantly associated with better metabolic control than HLL-HL. We did not find a significant association between HK-DM and metabolic control.

Conclusions: HL seems to be associated with better metabolic control. We also found a high prevalence of illiteracy and scarce knowledge about DM. Primary care physicians should promote HL to help patients achieve better metabolic control.