Effect of Health Literacy Intervention on Glycemic Control and Renal Function Among Thai Older Adults at Risk of Type 2 Diabetes Mellitus

PURPOSE: Diabetes patients with low health literacy often have poor health and clinical outcomes. The study aimed to assess the effectiveness of a health literacy intervention on glycemic control and renal function among Thai older adults at risk of type 2 diabetes mellitus (T2DM). METHODS: A quasi-experimental study was carried out in rural areas of Phayao Province in northern Thailand. The participants were older adults with T2DM who recorded blood glucose levels ranging from 140 to 180 mg/dL and who were not receiving prescribed medication. The intervention lasted 12 weeks, and data were collected at three points: baseline, post-intervention, and at 3 months’ follow-up. The study outcomes included the measurement of fasting blood sugar (FBS), hemoglobin A1C (HbA1c), and glomerular filtration rate (eGFR) levels after the intervention. A linear mixed model and generalized estimating equations model were used to assess the intervention effect for continuous and binary outcomes, respectively. RESULTS: From baseline to post-intervention, FBS and HbA1c decreased more in the intervention group than in the control group by 8.2 mg/dL (p < 0.001) and 0.1% (p = 0.029), respectively, whereas eGFR increased by 8.0 mL/min/1.73m2 (p < 0.001). The absolute effect of the intervention at follow-up was −9.8 units for FBS, −0.4 units for HbA1c, and 14.0 units for eGFR. Abnormal HbA1c level (≥6.5%) of the intervention group was reported as 70.3% at baseline, 31.3% at post-intervention, and 9.4% at follow-up. Compared to baseline levels, the T2DM patients who received the intervention were 0.31 times less likely to have abnormal HbA1c levels than the control subjects at follow-up (p = 0.003) who received no intervention. CONCLUSION: Our findings suggest that this intervention may potentially improve diabetes self-management and prevention behaviors, thereby reducing the diabetes burden in rural communities in northern Thailand.