Hadi Kooshiar - Department of Medical Surgical, Faculty of Nursing and Midwifery, Mashhad University of Medical Sciences, Mashhad, Iran.
Maryam Shoorvazi - Department of Medical Surgical, Faculty of Nursing and Midwifery, Mashhad University of Medical Sciences, Mashhad, Iran.
Zahra Dalir - Department of Medical Surgical, Faculty of Nursing and Midwifery, Mashhad University of Medical Sciences, Mashhad, Iran.
Masoud Hosseini - Department Medical Education, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

Background and objective: It is unclear how health literacy is associated with health-related quality of life. The aim of this study was to examine the mediating role of treatment regimen adherence between health literacy and health-related quality of life (HRQoL) in older adults with type ۲ diabetes mellitus (T۲DM). Material and methods: In this cross-sectional study, a multi-stage cluster sampling method was used to recruit ۳۰۰ diabetic patients aged ۶۰ years and over with diabetes. The abbreviated version of the Test of Functional Health Literacy in Adults (S-TOFHLA) and the Swedish Health-related Quality of Life (SWED-QUAL) instrument were used to measure health literacy and HRQoL, respectively. In addition, the Morisky Medication Adherence Scale (MMAS), the diet and exercise adherence questionnaire, were used to assess treatment regimen adherence. The four steps of Baron and Kenny’s procedure were implemented to test the mediation hypotheses. Results: The mean age of the respondents was ۶۴.۹۲ years. In addition, the mean of the respondents’ health literacy score was ۵۲.۸۲. The prevalence rates of the inadequate, marginal, and adequate health literacy of the respondents were ۷۰%, ۱۴.۷%, and ۱۵.۳%, respectively. Two items of treatment regimen adherence (medication adherence and diet and exercise adherence) had a partial mediating role between health literacy and quality of life in elderly diabetes patients. The result of Baron and Kenny’s procedure and Sobel’s test showed a significant mediation role in medication adherence (p = ۰.۰۰, Sobel’s Z = ۲.۷۷) and diet and exercise adherence (p = ۰.۰۰, Sobel’s Z = ۶.۲۶) between health literacy and HRQoL. Conclusion: Medication adherence, diet adherence, and exercise adherence are mediating factors in relationship between health literacy and HRQoL that increase the health literacy and quality of life in older adults with T۲DM.

Diabetes Mellitus, Frail Elderly, Health Literacy, Quality of life, Patient Compliance