Studies have shown that only about half of American adults have basic reading and numerical skills, and a lack of these skills can compromise health literacy. Low health literacy has been associated with poorer health outcomes, higher health costs, and reduced patient satisfaction with healthcare providers. “Low health literacy is especially prevalent among patients with low socioeconomic status, the elderly, and those whose primary language is not English,” explains Andrea J. Apter, MD, MSc. “This reflects the limited educational opportunities that are available for these patient groups. In these same patients, the prevalence of asthma morbidity is high.” Low numeric literacy or numeracy has also been linked to lower asthma-related quality of life (QOL) and prior ED visits and hospitalizations for asthma.

Numeric & Print Literacy

The mechanisms governing the relationship between low health literacy and poor outcomes in asthma have not been well defined in clinical research. To address this gap, Dr. Apter and colleagues conducted a study to assess whether literacy is related to subsequent asthma self-management and asthma outcomes. Published in the Journal of Allergy and Clinical Immunology, the study assessed numeric and print literacy in adults with moderate or severe asthma and its impact on subsequent electronically monitored adherence and asthma outcomes for 26 weeks.



According to findings, participants with higher health literacy had better asthma-related QOL and improved disease control than those with lower health literacy. For every point higher that patients scored on a measure of health-related print literacy, better QOL and asthma control was observed, as indicated by a 0.63-unit increase in the Mini-Asthma Quality of Life Questionnaire and a 0.52-point improvement in the Asthma Control Questionnaire. When patients scored 1 point higher on the Asthma Numeracy Questionnaire (a measure of asthma-related numerical ability), subsequent asthma-related QOL was better, as demonstrated by a 0.14-unit higher score in the Mini-Asthma Quality of Life Questionnaire. Whereas other cross-sectional studies have linked health literacy and outcomes, the longitudinal design of this study suggested a more direct relationship.

Assessing Implications

“Our study shows that it’s important for clinicians to consider health literacy levels when they talk with their patients,” says Dr. Apter. “At the same time, we must recognize that the relationship between health outcomes and literacy is complex. For example, race was strongly correlated with income and educational attainment in our analysis. This finding illustrates how several components of health literacy—race, ethnicity, education, and income—are interconnected.”

“It’s important for clinicians to consider health literacy levels
when they talk with their patients.”

Dr. Apter notes that more research is needed to develop interventions that address health disparities. “Interventions that account for and address the literacy needs of patients may improve asthma outcomes. In the meantime, clinicians should strive to simplify treatment instructions. We should also consider integrating health literacy into electronic health records and other technologies to take better advantage of educational opportunities for patients.”


Apter AJ, Wan F, Reisine S, et al. The association of health literacy with adherence and outcomes in moderate-severe asthma. J Allergy Clin Immunol. 2013 Apr 13 [Epub ahead of print]. Available at:

Apter AJ, Wang X, Bogen DK, et al. Problem solving to improve adherence and asthma outcomes in urban adults with moderate or severe asthma: a randomized controlled trial. J Allergy Clin Immunol. 2011;128:516-523.

Mancuso CA, Rincon M. Impact of health literacy on longitudinal asthma outcomes. J Gen Intern Med. 2006;21:813-817.

Berkman ND, Sheridan SL, Donahue KE, et al. Health literacy interventions and outcomes: an updated systematic review. Evid Rep Technol Assess (Full Rep). 2011;199:1-941.