The Demographic Assessment for Health Literacy (DAHL): a new tool for estimating associations between health literacy and outcomes in national surveys.
OBJECTIVE
To impute limited health literacy from commonly measured socio-demographic data and to compare it to the Short-Test of Functional Health Literacy in Adults (S-TOFHLA) for estimating the influence of limited health literacy on health status in the elderly.


METHODS
The Prudential Medicare Study assesses the S-TOFHLA score, leading to a "reference standard" classification of 25% of people with inadequate literacy; the National Health Interview Survey has no such assessment. We estimated a regression of S-TOFHLA on sex, age, years of schooling, and race/ethnicity in The Prudential Medicare Study data to derive a Demographic Assessment for Health Literacy (DAHL) score, and imputed inadequate literacy to the 25% with the lowest DAHL scores. Using regression, we then examined associations between several health status measures (including hypertension, diabetes, physical and mental SF-12) and inadequate literacy (imputed or test-based).


RESULTS
Estimates of association using imputed inadequate literacy closely approximate those obtained using S-TOFHLA-based inadequate literacy for most outcomes examined.


CONCLUSIONS
As few population surveys measure health literacy, the DAHL, a readily calculated health literacy proxy score, may be useful for expanding the scope of health literacy research in national survey data.
Hanchate
Amresh D
AD
Section of General Internal Medicine, Boston University School of Medicine, Boston, MA 01532, USA. hanchate@bu.edu
Ash
Arlene S
AS
Gazmararian
Julie A
JA
Wolf
Michael S
MS
Paasche-Orlow
Michael K
MK
D000368:Aged; D000369:Aged, 80 and over; D004522:Educational Status; D005260:Female; D015438:Health Behavior; D006266:Health Education / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D007722:Health Knowledge, Attitudes, Practice; D006306:Health Surveys; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology