Rethinking health numeracy: a multidisciplinary literature review

Abstract

The purpose of this review is to organize various published conceptions of health numeracy and to discuss how health numeracy contributes to the productive use of quantitative information for health. We define health numeracy as the individual-level skills needed to understand and use quantitative health information, including basic computation skills, ability to use information in documents and non-text formats such as graphs, and ability to communicate orally. We also identify two other factors affecting whether a consumer can use quantitative health information: design of documents and other information artifacts, and health-care providers' communication skills. We draw upon the distributed cognition perspective to argue that essential ingredients for the productive use of quantitative health information include not only health numeracy but also good provider communication skills, as well as documents and devices that are designed to enhance comprehension and cognition.

Figure 1

The successful use of quantitative health information requires basic quantitative skills on the part of the patient, but it also requires interactions with the person providing the information (who may be a doctor, a nurse, a counselor, or a friend or family member), and information artifacts (such as a written document, a website, or a medical device). Both the patient and the information provider must be able to manipulate and interpret quantitative information, as well as communicate about it. Both parties also need skills for interacting with information artifacts, such as document literacy and graphical literacy. Individual quantitative skills and artifact-interaction skills are both strongly affected by the quality of information design; good design can ease cognitive burden and improve comprehension.

Figure 2

The quantity 1/2 may be represented in a variety of logically equivalent but cognitively different ways. Reprinted from p. 101. With permission.

Figure 3

Systolic and diastolic blood pressure displayed in a computer-generated table as part of the IDEATel telehealth program, and (inset) on the blood pressure meter. Some elderly participants who had no difficulty reading the values on the meter were unable to understand the same information displayed in the table.