This paper reports the development of SAHL-S&E, designed to provide a comparable test of health literacy for Spanish-speaking and English-speaking populations. Results show that the instrument has good validity and reliability. Guessing does not appear to be a concern if clear instruction is given before the test. The instrument contains only 18 items and is easy to administer. We estimate that the administration would take only 2–3 minutes and require minimal training. (The Spanish and English version of SAHL-S&E and the user guides are included in the Appendix.) A rather high cutoff point is found for low health literacy (≤14), suggesting that the SAHL-S&E is particularly useful for identifying individuals with low health literacy. The test information function confirms that the instrument is highly reliable at the lower range of scores.
In validating the instrument, we found that SAHL-S had a higher correlation with SAHLSA than with Spanish TOFHLA. Similarly, the correlation between SAHL-E and REALM was higher than that between SAHL-E and English TOFHLA. The findings may reflect the fact that the design of SAHL-S&E, essentially a word recognition test of reading ability, is the same as SAHLSA and similar to REALM. We also found that the resulting instrument had a lower correlation with years of schooling in the Spanish-speaking sample. There are two plausible explanations. First, in comparison with education experience of English speakers, Spanish speakers, whose education was obtained in multiple countries and systems, may have more heterogeneous education experience. Second, although consistent with the standard testing in the U.S. education system, the format of the test (a pronunciation test and a multiple-choice test for comprehension) may be unusual for Spanish speakers. In other words, Spanish-speaking respondents in our sample, compared with English-speaking respondents with the same level of formal schooling, may be less familiar with the multiple-choice format of the test and thus have a poorer performance on the test.
Several limitations are worth noting. The instrument was developed based on standard, “dictionary” Spanish and English. Further testing of the instrument may be needed in different Spanish- and English-speaking subpopulations who are accustomed to using different idiomatic expressions. As with other health literacy instruments such as TOFHLA and REALM, SAHL-S&E is a reading test. It assesses specifically an individual's reading skill in the health care context. The design is based on the assumption that reading ability is a basic literacy skill, without which patients would have difficulty functioning in and negotiating the health care system. However reasonable the assumption is, it should be noted that the instrument does not capture other skills such as numeracy and interpersonal communication that may also be important in health care. Furthermore, similar to prior instrument development studies, our study did not include a random, representative sample of Spanish speakers and English speakers in the community. The clinic-based participants recruited for the study may be more receptive to a health literacy test. What kind of difficulties may arise in applying the SAHL-S&E to a community-based sample remains to be evaluated. Finally, as we have noted, the instrument is particularly suitable for identifying individuals with low health literacy. For individuals with a >14 score, the instrument may not be sensitive enough to distinguish different health literacy levels.
Despite these limitations, the instrument is robust and has several practical applications. First, unlike other instruments, the comparability between the Spanish and English versions of the instrument is established through rigorous psychometric evaluation. It offers a reliable way to assess and compare the level of low health literacy between Spanish and English speakers.
Second, the instrument may be used to screen for individual health literacy level in public health and clinical settings that serve a high concentration of English-speaking or Spanish-speaking patients or a mixed patient population. Being able to identify patients with low health literacy can alert health care providers to the possibility that these patients may have difficulty with printed educational materials, communicating their symptoms to physicians, or following medical instructions (Bass et al. 2002
; Chew, Bradley, and Boyko 2004
; Institute of Medicine 2004
;). Increased awareness among health care practitioners of the special health and personal needs of low health literacy patients may help reduce the level of linguistic complexity used in provider–patient communications, thus preventing serious medical errors due to misunderstanding. This, in turn, has the potential to improve quality of care and reduce health care cost. These potential advantages asides, the value of health literacy screening may still be debatable because of concerns about patient stigmatization and embarrassment (Parikh et al. 1996
; Wolf et al. 2007
;). Two recent studies suggest that patients are not adverse to health literacy screening if protection of personal information is exercised (Ryan et al. 2008
; VanGeest, Welch, and Weinber 2010
;). However, more research is needed to assess the conditions under which health literacy screening may be appropriate in clinical settings.
Third, the instrument could be used to assess the level of health literacy in local communities. The information could be used to guide the design of appropriate health educational materials (written and/or multimedia) or for devising community intervention programs that are comparable with the health literacy level of the local population (Brandes 1996
; Davis et al. 1998
Finally, a comparable health literacy instrument for Spanish and English speakers would facilitate comparisons in research. Instead of stratifying subjects on language in health literacy research, researchers could combine samples and use SAHL-S&E to identify those with low health literacy in their analysis.