Ideal instruments used to measure health literacy related to medication use: A systematic review

Pharmacotherapy literacy level and predictors of low literacy among diabetes mellitus type 2 patients in Serbia

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.

Development and content validation of the medication literacy test for older adults (TELUMI)

OBJECTIVES

Medication literacy comprises the skills needed to access, understand, and act on medication information. Low medication literacy is frequent among older adults, making them more susceptible to negative health outcomes. The aim of this study was to develop and evaluate the content validity of an instrument to measure medication literacy in this population.

METHOD

Multistage methodological study. Items were generated according to a conceptual model and a literature review. The instrument was submitted to a panel of experts to assess item's relevance, clarity, and theoretical classification. Subsequently, the instrument was applied to the target population to assess its comprehensibility.

RESULTS

Content Validity Index results indicated excellent agreement among experts on the instrument's relevance (0.98) and clarity (0.91). Overall agreement between experts regarding the theoretical subdimensions was moderate [Fleiss' kappa=0.57 (p = 0.00)]. Items were reported to be fully understood by most representatives of the target population. The final version of the instrument had 33 items divided into eight scenarios of medication use.

CONCLUSION

The instrument seems to have adequate content validity and good suitability for the target population. Therefore, it can help health professionals to identify older adults with low medication literacy, aiming to improve their medication use skills.

Measuring health literacy: A systematic review and bibliometric analysis of instruments from 1993 to 2021

BACKGROUND

It has been about 30 years since the first health literacy instrument was developed. This study aimed to review all existing instruments to summarize the current knowledge on the development of existing measurement instruments and their possible translation and validation in other languages different from the original languages.

METHODS

The review was conducted using PubMed, Web of Science, Scopus, and Google Scholar on all published papers on health literacy instrument development and psychometric properties in English biomedical journals from 1993 to the end of 2021.

RESULTS

The findings were summarized and synthesized on several headings, including general instruments, condition specific health literacy instruments (disease & content), population- specific instruments, and electronic health. Overall, 4848 citations were retrieved. After removing duplicates (n = 2336) and non-related papers (n = 2175), 361 studies (162 papers introducing an instrument and 199 papers reporting translation and psychometric properties of an original instrument) were selected for the final review. The original instruments included 39 general health literacy instruments, 90 condition specific (disease or content) health literacy instruments, 22 population- specific instruments, and 11 electronic health literacy instruments. Almost all papers reported reliability and validity, and the findings indicated that most existing health literacy instruments benefit from some relatively good psychometric properties.

CONCLUSION

This review highlighted that there were more than enough instruments for measuring health literacy. In addition, we found that a number of instruments did not report psychometric properties sufficiently. However, evidence suggest that well developed instruments and those reported adequate measures of validation could be helpful if appropriately selected based on objectives of a given study. Perhaps an authorized institution such as World Health Organization should take responsibility and provide a clear guideline for measuring health literacy as appropriate.