Background: Pharmacotherapy literacy (PTHL) is a specific ability to safely access, appraise and understand the available information concerning medication and to calculate and act accordingly. The concept of PTHL is mostly unknown for the majority of diabetes mellitus type 2 (DMT2) patients in Serbia. With diabetes being one of the major public health problems in Serbia with a prevalence of 9.1%, this two-study research aims at constructing performance-based instrument and estimating the prevalence of PTHL levels and identification of predictors of low PTHL scores in patients with DMT2. Methods: Multistage study was performed to adapt the existing performance–based instrument (PTHL-SR) into specific questionnaire for DMT2 population (PTHL-DM instrument). PTHL levels were assessed through cross-sectional study categorising patients into groups of low, medium, and high PTHL levels. We considered 19 predictors for low PTHL scores, from sociodemographic characteristics, health behaviours and health characteristics, access to health-related information and empowerment-related indicators. Univariate and multivariate logistic regression analyses were used to determine independent predictors of low PTHL. Results: The final 15-item PTHL-DM instrument proved to have satisfactory reliability (KR20 = 0.475) and internal reliability [ICC for the whole instrument was 0.97 with 95% confidence intervals (0.95–0.99)]. Positive correlation (rho = 0.69) between PTHL-DM score (15 questions) and the total PTHL-SR score (14 questions) was also observed. It was demonstrated that the majority of 350 patients had low PTHL (62%), and only 5% high PTHL level. Mean score on PTHL-DM was 7.8 ± 2.3. Probability of low PTHL increased among smokers, patients with low interest in health and those who estimated their health as bad. Patients who used pharmacists as sourse of information were less likely to be pharmacotherapy illiterate. Combined therapy with insulin and Oral Hypoglycemic Agents was associated with higher PTHL. Conclusions: Our data indicate that specific PTHL-DM tool is objective, valid, and reliable. It was found that low level of PTHL prevailed among DMT2 patients. Medication literacy is influenced by age, residence, education, and family status. Patients with better health literacy also reported better health behaviours. Different patient empowerment programs and approaches aimed at raising PTHL would be essential to improve self-management and control of this widespread chronic disease in Serbia.

Introduction: Obtaining, understanding, interpreting, and acting on health information enables people with diabetes to engage and make health decisions in various contexts. Hence, inadequate health literacy (HL) could pose a problem in making self-care decisions and in self-management for diabetes. By applying multidimensional instruments to assess HL, it is possible to differentiate domains of functional, communicative, and critical HL. Objectives: Primarily, this study aimed to measure the prevalence of inadequate HL among type 2 diabetes mellitus patients and to analyze the predictors influencing health literacy levels. Secondly, we analyzed if different self-reported measures, unidimensional instruments (Brief Health Literacy instruments (BRIEF-4 and abbreviated version BRIEF-3), and multidimensional instruments (Functional, Communicative and Critical health literacy instrument (FCCHL)) have the same findings. Methods: The cross-sectional study was conducted within one primary care institution in Serbia between March and September 2021. Data were collected through Serbian versions of BRIEF-4, BRIEF-3, and FCCHL-SR12. A chi-square test, Fisher’s exact test, and simple logistic regression were used to measure the association between the associated factors and health literacy level. Multivariate analyses were performed with significant predictors from univariate analyses. Results: Overall, 350 patients participated in the study. They were primarily males (55.4%) and had a mean age of 61.5 years (SD = 10.5), ranging from 31 to 82 years. The prevalence of inadequate HL was estimated to be 42.2% (FCCHL-SR12), 36.9% (BRIEF-3) and 33.8% (BRIEF-4). There are variations in the assessment of marginal and adequate HL by different instruments. The highest association was shown between BRIEF-3 and total FCCHL-SR12 score (0.204, p < 0.01). The total FCCHL-SR12 score correlates better with the abbreviated BRIEF instrument (BRIEF-3) than with BRIEF-4 (0.190, p < 0.01). All instruments indicated the highest levels for the communicative HL domain and the lowest for the functional HL domain with significant difference in functional HL between the functional HL of FCCHL-SR12 and both BRIEF-3 and BRIEF-4 (p = 0.006 and 0.008, respectively). Depending on applied instruments, we identified several variables (sociodemographic, access to health-related information, empowerment-related indicators, type of therapy, and frequency of drug administration) that could significantly predict inadequate HL. Probability of inadequate HL increased with older age, fewer children, lower education level, and higher consumption of alcohol. Only high education was associated with a lower probability of inadequate HL for all three instruments. Conclusions: The results we obtained indicate that patients in our study may have been more functionally illiterate, but differences between functional level could be observed if assessed by unidimensional and multidimensional instruments. The proportion of patients with inadequate HL is approximately similar as assessed by all three instruments. According to the association between HL and educational level in DMT2 patients we should investigate methods of further improvement.

Thoroughly validated instruments can provide a more accurate and reliable picture of how the instrument works and of the level of health literacy in people with type 2 diabetes mellitus (T2DM). The present work aimed at cross-cultural adaptation and validation of the Functional, Communicative and Critical Health Literacy Instrument (FCCHL) in patients with T2DM in Serbia. After translation and back-translation, views from an expert group, one cognitive interview study (n = 10) and one survey study (n = 130) were conducted among samples of diabetic patients. Item analysis, internal consistency, content validity, confirmatory factor analysis (CFA) and reliability testing were performed. When all 14 items were analyzed, loading factors were above 0.55, but without adequate model fit. After removing two items with the lowest loadings FHL1 and IHL2 the fit indexes indicated a reasonable normed χ² (SB scaled χ²/df = 1.90). CFI was 0.916 with SRMR = 0.0676 and RMSEA = 0.0831. To determine internal consistency, Cronbach’s alpha coefficient was 0.796 for the whole FCCHL-SR12. With only minor modifications compared to the English version, the 12-item FCCHL instrument is valid and reliable and can be used to measure health literacy among Serbian diabetic patients. However, future research on a larger population in Serbia is necessary for measuring the levels of HL and their relationship with other determinants in this country.