title: Aging and Functional Health Literacy: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  To review the evidence on the association between age and limited health literacy, overall and by health literacy test, and to investigate the mediating role of cognitive function.
  
  
  METHODS
  The Embase, MEDLINE, and PsycINFO databases were searched. Eligible studies were conducted in any country or language, included participants aged ≥50 years, presented a measure of association between age and health literacy, and were published through September 2013.
  
  
  RESULTS
  Seventy analyses in 60 studies were included in the systematic review; 29 of these were included in the meta-analysis. Older age was strongly associated with limited health literacy in analyses that measured health literacy as reading comprehension, reasoning, and numeracy skills (random-effects odds ratio [OR] = 4.20; 95% confidence interval [CI]: 3.13-5.64). By contrast, older age was weakly associated with limited health literacy in studies that measured health literacy as medical vocabulary (random-effects OR = 1.19; 95% CI: 1.03-1.37). Evidence on the mediating role of cognitive function was limited.
  
  
  CONCLUSIONS
  Health literacy tests that utilize a range of fluid cognitive abilities and mirror everyday health tasks frequently observe skill limitations among older adults. Vocabulary-based health literacy skills appear more stable with age. Researchers should select measurement tests wisely when assessing health literacy of older adults.
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK. l.kobayashi.12@ucl.ac.uk.
authors.forename: Lindsay C
authors.initials: LC
authors.lastname: Kobayashi
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK.
authors.forename: Jane
authors.initials: J
authors.lastname: Wardle
authors.affiliation: Health Literacy and Learning Program, Division of General Internal Medicine, Feinberg School of Medicine at Northwestern University, Chicago, Illinois. Department of Learning Sciences, School of Education and Social Policy, Northwestern University, Evanston, Illinois.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Wolf
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK.
authors.forename: Christian
authors.initials: C
authors.lastname: von Wagner
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D003071:Cognition; D032882:Comprehension; D005260:Female; D057220:Health Literacy; D006801:Humans; D008297:Male; D008875:Middle Aged; D013223:Statistics as Topic
keywords: Adults; Aging; Cognition; Health literacy; Measurement