Objective
The intent of the study was to develop and validate a comparable health literacy test for Spanish-speaking and English-speaking populations.
Study Design
The design of the instrument, named the Short Assessment of Health Literacy-Spanish and English (SAHL-S&E), combined a word recognition test, as appearing in the Rapid Estimate of Adult Literacy in Medicine (REALM), and a comprehension test using multiple-choice questions designed by an expert panel. We employed the item response theory in developing and validating the instrument.
Data Collection
Validation of SAHL-S&E involved testing and comparing the instrument with other health literacy instruments in a sample of 201 Spanish-speaking and 202 English-speaking subjects recruited from the Ambulatory Care Center at the University of North Carolina Healthcare System.
Principal Findings
Based on item response theory analysis, 18 items were retained in the comparable test. The Spanish version of the test, SAHL-S, was highly correlated with another Spanish health literacy instrument, SAHLSA (r = 0.88, p < 0.05). The English version, SAHL-E, had high correlations with REALM (r = 0.94, p < 0.05) and the English Test of Functional Health Literacy in Adults (r = 0.68, p < 0.05). Significant correlations were found between SAHL-S&E and years of schooling in both Spanish and English-speaking samples (r = 0.15 and r = 0.39, respectively). SAHL-S&E displayed satisfactory reliability of 0.80 and 0.89 in the Spanish and English-speaking samples, respectively. IRT analysis indicated that the SAHL-S&E score was highly reliable for individuals with a low level of health literacy.
Conclusions
The new instrument, SAHL-S&E, has good reliability and validity. It is particularly useful for identifying individuals with low health literacy and could be used in clinical or community settings to screen for low health literacy among Spanish and English speakers.