Health Literacy and Treatment Adherence In Older Adults: A Systematic Meta ‐ review

BJM Geboers2, Julii Brainard1, Yoon Loke1, Andrea de Winter2. 1UEA, Norwich, UK, 2UMCG, Groningen, The Netherlands

Health literacy (HL) may be defined as “ The degree to which people are able to access, understand, appraise and communicate information to engage with the demands of different health contexts in order to promote and maintain good health across the life course ” (1). Poor HL is strongly associated with poor health outcomes (2). A suggested causal pathway is poor adherence to medical advice and treatment plans. This study aimed to collate evidence from available systematic reviews on the links between HL and adherence in older adults, and to examine the effectiveness of adherence interventions in older adults with low health literacy. We also explored associations between educational level and adherence.

Methods: We conducted a meta‐review to identify existing systematic reviews that evaluated i) the link between treatment adherence and health literacy, or ii) effect of literacy interventions on adherence. Eight scientific databases were searched and references of included reviews were checked. The selection procedure, data‐extraction and quality assessment were conducted by two independent reviewers with a third reviewer adjudicating in areas of disagreement. Of 1330 unique articles initially identified, 1229 were screened by title and abstract and removed using exclusion criteria. 101 articles were fully reviewed with quality assessment conducted using the AMSTAR tool (3). On the 11-point AMSTAR scale, the final 12 selected reviews had mean and median scores both = 6.5, range of 3-10. A narrative analysis was produced for the conclusions in the selected reviews and their assessments of any relationship between HL or education levels and adherence.

Results: 7 reviews (based on 13 original studies) found inconsistent and/or insignificant associations between health literacy and adherence. There was also no consistent association between educational level and adherence. 7 reviews reported on 7 distinct adherence interventions focused on older adults with low health literacy. Adherence interventions covered a wide range of strategies. Some of these were effective in improving adherence, independent of level of health literacy. Five interventions reported significant improvements in adherence outcomes. Interventions aimed at educating patients and providing support to change or maintain adherence behaviours appeared to mitigate the negative effects of low health literacy for several outcomes.

Conclusions: No consistent association between health literacy or educational levels and adherence in older adults was found. However, some adherence interventions could be productive for older adults with low health literacy, and may even decrease disparities in health status due to low health literacy.

(1) Kwan B, Frankish J, Rootman I, et al. (2006) The development and validation of measures of “ health literacy ” in different populations. Vancouver: University of British Columbia,.

(2) Berkman ND et al. Annals of Internal Medicine, 155:97, 2011

(3) Shea BJ et al. BMC Med Res Methodol 7:10, 2007.