Sociodemographic factors are important and well-documented risk factors for US health care outcomes.1 Health communication-related factors, however, remain understudied, despite the suggestion that they play an important role in the health of patients in this country.2 , 3 Focus on language is particularly important as our nation becomes increasingly diverse, with at least 20% of the US population speaking a language other than English at home.

This study by Kim et al.4 utilizes the Centers for Disease Control and Prevention (CDC) National Health and Nutrition Examination Survey (NHANES) for its large sample, a significant improvement upon most studies on this topic, which rely on small, local samples. The authors investigate a proxy for English proficiency by measuring survey participants’ use of a Spanish instrument or interpreter. Their findings indicate that limited English proficiency, as measured by this indicator, is associated with poorly controlled hypertension.

Their results highlight the fact that self-reported language may not accurately reflect a patient’s ability to navigate the English-speaking US health care system. As they note, using this measure for English proficiency, there was no association with elevated blood pressure on physical exam. For some patients who are truly bilingual, self-reported language may underestimate their proficiency, while others may overestimate their ability to effectively communicate in and understand English.

A limitation in the application of the results of this study is that utilization of a non-English instrument or interpreter as a proxy for limited English proficiency will only be possible in clinical and research settings where these options are available.

Future efforts should be aimed at validation of this proxy marker for limited English proficiency. It would be interesting to see this measure compared to one or more of the existing validated instruments for measuring oral and written English proficiency. In addition, researchers must continue to investigate the disparities associated with barriers to effective health communication. There is evidence to suggest that the use of professional interpreters, patient care navigators and other communication supports can mitigate some of these gaps.5 Effective interventions could have a significant impact on use of resources, cost, morbidity and mortality.