title: Health literacy and adherence to medical treatment in chronic and acute illness: A meta-analysis.
abstract: To use meta-analytic techniques to assess average effect sizes in studies of: (1) the correlation between patient health literacy and both medication and non-medication adherence, and (2) the efficacy of health literacy interventions on improving health literacy and treatment adherence.
  
  
  
  PsychINFO and PubMed databases were searched (1948-2012). A total of 220 published articles met the criteria for inclusion; effect sizes were extracted and articles were coded for moderators.
  
  
  
  Health literacy was positively associated with adherence (r=0.14), and this association was significantly higher among non-medication regimens and in samples with cardiovascular disease. Health literacy interventions increased both health literacy (r=0.22) and adherence outcomes (r=0.16). Moderator analyses revealed greater intervention efficacy when health literacy and adherence were assessed using subjective measures compared to objective measures. Health literacy interventions had a greater effect on adherence in samples of lower income and of racial-ethnic minority patients than in non-minority and higher income samples.
  
  
  
  This is the first study to synthesize both correlational and intervention studies examining the relationship between health literacy and adherence to both medication and non-medication regimens.
  
  
  
  These findings demonstrate the importance of health literacy and the efficacy of health literacy interventions especially among more vulnerable patient groups.
authors.affiliation: University of California Riverside, Department of Psychology, 900 University Avenue, Riverside, CA 92521, United States. Electronic address: trishmiller122@gmail.com.
authors.forename: Tricia A
authors.initials: TA
authors.lastname: Miller
mesh_terms: D000208:Acute Disease / Q000628:therapy*; D002318:Cardiovascular Diseases / Q000628:therapy; D002908:Chronic Disease / Q000628:therapy*; D057220:Health Literacy; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D010349:Patient Compliance; D010353:Patient Education as Topic
keywords: Compliance; Health literacy; Health literacy interventions; Meta-analysis; Patient adherence