Effects of Estimated Community-Level Health Literacy on Treatment Initiation and Preventive Care Among Older Adults with Newly Diagnosed Diabetes

Gang Fang,1 Stacy Cooper Bailey,2 Izabela E Annis,1 Michael K Paasche-Orlow,3 Michael S Wolf,2 Laurie T Martin,4 Michael Emch,5 M Alan Brookhart,6 Karen B Farris7 1Division of Pharmaceutical Outcomes and Policy, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 2Division of General Internal Medicine & Geriatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; 3Section of General Internal Medicine, Boston University School of Medicine, Boston, MA, USA; 4RAND Corporation, Arlington, VA, USA; 5Department of Geography and Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA; 6Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA; 7College of Pharmacy, The University of Michigan, Ann Arbor, MI, USACorrespondence: Gang FangDivision of Pharmaceutical Outcomes and Policy, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, 2202, Kerr Hall, Chapel Hill, NC 27599-7573, USATel +1 919-966-7517Fax +1 919-966-8486Email gang_fang@unc.eduPurpose: Individual measures of health literacy are not feasible for administration on a large scale, yet estimates of community-level health literacy in the US recently became available. We sought to investigate whether community-level health literacy estimates are associated with the initiation of oral antihyperglycemic agents (OHA) and the use of standard preventive care services among older adults with newly diagnosed diabetes.Patients and methods: We conducted a retrospective cohort study of 169,758 patients, ≥65 years old with hypertension and newly diagnosed type 2 diabetes using 2007–2011 data from the Center for Medicare and Medicaid Services Chronic Conditions Warehouse. We examined the relationship between community-level health literacy estimates and initiation of OHA, receipt of flu shots, eye exams, Hemoglobin A1c tests, and lipid tests within 12 months post diabetes diagnosis.Results: Patients living in communities with above basic health literacy (vs. basic/below basic) were 15% more likely to initiate OHA (Hazard Ratio=1.15; 95% CI 1.12 to 1.18). After classifying the health literacy distribution as quintiles, the analysis revealed a dose–response relationship with OHA initiation that plateaued at the third and fourth quintiles and declined at the fifth quintile. Individuals residing in communities with higher health literacy were more likely to participate in preventive care services (relative risk ranged from 1.09 for lipid test [95% CI 1.07–1.11] to 1.43 for flu shot [95% CI 1.41–1.46]).Conclusion: Community-level health literacy estimates were associated with the initiation of OHA and uptake of standard preventive care services in older adults. Community-level health literacy may help to inform targeted diabetes education and support efforts.Keywords: health literacy, diabetes mellitus, adherence, preventive care