title: Examining the causal model linking health literacy to health outcomes of asthma patients.
abstract: OBJECTIVE
  To explore health literacy status in asthma patients and to examine the causal model linking health literacy to health outcome-related factors via mediator and moderator variables.
  
  
  BACKGROUND
  Understanding how low health literacy may influence health outcomes is important.
  
  
  METHODS
  This is a cross-sectional survey study.
  
  
  METHODS
  A total of 326 asthma patients aged 20 years and older (average: 51 ± 18·3 years) were recruited by purposive sampling from pulmonary medicine outpatient departments at three medical centres and a regional teaching hospital in northern Taiwan. Data were collected via structured questionnaires, including measures of socio-demographic and disease characteristics; medical decision-making; asthma knowledge, attitudes and self-efficacy; healthcare experience and health outcome-related factors (metered-dose inhaler/dry-powder inhaler usage proficiency, medical use, self-management behaviour). Three hundred patients who met the inclusion criteria and completed the questionnaire survey were analysed.
  
  
  RESULTS
  Overall, 217 subjects (72·3%) had adequate functional health literacy, 42 (14%) had inadequate functional health literacy, and 41 (13·7%) had marginal functional health literacy. Subjects' average asthma knowledge, attitudes and self-efficacy scores were 7·23 ± 2·69, 51·46 ± 6·18 and 58·31 ± 8·10, respectively. Health literacy correlated positively with asthma knowledge (r = 0·605), attitudes (r = 0·192) and medical decision-making (r = 0·413).
  
  
  CONCLUSIONS
  Health literacy is positively associated with proficiency in metered-dose inhaler usage, asthma knowledge, attitudes and medical decision-making, but is not significantly associated with medical care use and self-management behaviour. Health literacy had an indirect effect on self-management behaviour through the mediation effect of asthma attitudes. No moderator was found for the effect of health literacy on health outcome-related factors.
  
  
  CONCLUSIONS
  Results of this study may help to develop adequate intervention strategies to improve the health outcomes of asthma patients.
authors: Department of Nursing, Taipei Veterans General Hospital, Taipei, Taiwan; School of Nursing, National Defense Medical Center, Taipei, Taiwan.
authors: Kwua-Yun
authors: KY
authors: Wang
authors: Nain-Feng
authors: NF
authors: Chu
authors: Sieh-Hwa
authors: SH
authors: Lin
authors: I-Chyun
authors: IC
authors: Chiang
authors: Wann-Cherng
authors: WC
authors: Perng
authors: Hsiang-Ru
authors: HR
authors: Lai
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy* / Q000451:nursing / Q000523:psychology; D003430:Cross-Sectional Studies; D005260:Female; D057220:Health Literacy; D006801:Humans; D008297:Male; D036501:Metered Dose Inhalers; D008875:Middle Aged; D012651:Self Medication; D011795:Surveys and Questionnaires; D013624:Taiwan; D016896:Treatment Outcome; D055815:Young Adult
keywords: asthma; causal model; health literacy; mediator; moderator; outcomes