Association between limited English proficiency and understanding prescription labels among five ethnic groups in California.

OBJECTIVE: Misunderstanding of prescription labels results in adverse drug events and non-adherence. We assessed the effect of limited English and other factors on prescription understanding among five ethnic groups in a controlled analysis.
DESIGN: Subjects were respondents to California's 2007 Health Interview Survey who received a prescription in the past year. In separate logistic regressions, limited English's effect on self-reported prescription understanding - controlling for bilingual doctor, education level, medications for chronic conditions, disability, years in USA, citizenship and socio-demographics - was estimated for Mexicans, Central Americans, Chinese, Koreans, and Vietnamese.
RESULTS: Unweighted sample size was 48,968. Approximately 14% had limited English and 8% had difficulty in understanding prescriptions. In multivariate analysis, limited English increased odds of difficulty in understanding prescriptions by three times for Mexicans, Central Americans, and Koreans, and four times for Chinese; it was insignificant for Vietnamese. Generally, having a bilingual doctor reduced odds of difficulty while disability, low education, low income or recent immigration increased odds of difficulty. Effects varied according to the ethnic group. In controlled analysis, Chinese and Korean ethnicity increased odds of difficulty compared to Mexican or Central American ethnicity; Vietnamese ethnicity reduced odds of difficulty compared to others.
CONCLUSIONS: Limited English blocked prescription understanding for all groups except Vietnamese. Translated prescription labels and interpreted in-person pharmacy consultations are indicated. Education and ethnicity affected prescription understanding; prescription instructions must be compatible with patients' educational level and culture. Bilingual/bicultural providers and interpreters can help bridge linguistic/cultural gaps but efforts should be made to ensure that they are truly culturally and linguistically concordant. Linguistic, cultural or educational needs should be noted in the patient's record or on the prescription to alert pharmacy staff. Sub-populations needing extra support include chronically ill, disabled, recent immigrants, low-income or rural inhabitants. Community outreach workers may provide an effective strategy for assisting these sub-populations with prescriptions.