Measuring health literacy across diverse populations

BACKGROUND: Definitions of health literacy vary and existing health literacy measures cannot be widely applied across culturally diverse groups.

OBJECTIVE: To present health literacy findings from our multimethod study, “The Impact of Cultural Differences on Health Literacy and Chronic Disease Outcomes,” based at a Massachusetts community health center.

METHODS: Epidemiological surveys were administered by bilingual interviewers to 300 participants from 4 ethnic groups. We matched health literacy scales to language. All participants completed the TOFHLA numeracy scale, and Latinos completed the SAHLSA, while English-speakers (White and Black) completed the REALM. We translated the TOFHLA numeracy scale into Vietnamese. We completed in-depth interviews (n=18) and focus groups (n=7) with a subset of participants.

RESULTS: We found significant variation in TOFHLA numeracy scores among ethnic groups, with African American and White means similar to each other and Latino and Vietnamese means similar to each other (p=.000). Among non-English-speakers, TOFHLA scores were positively associated with: fluency in and comfort with English (p<.05), years of education, and acculturation (for Latinos). One-third of Latinos had inadequate health literacy as measured by the SAHLSA, compared with 60% of white and 39% of African-American patients (using the REALM, p<.04). Vietnamese patients had the lowest mean TOFHLA numeracy scores. Qualitative interviews with participants indicated a wide range of interpretations of TOFHLA numeracy questions.

CONCLUSIONS: Current measures of health literacy have proved inadequate for uniformly assessing diverse groups. Translation of existing measures into other languages (e.g., Vietnamese) may not adequately measure real-life disease management capacity among non-English speaking populations.