Developing a Better and More User-Friendly Numeracy Scale for Patients

• Published in: Health literacy research and practice 2019-07, Vol.3 (3), p.e174-e180
• Main Authors: Hill, W Trey, Brase, Gary L, Kenney, Kevin L
• Format: Article
• Language: English
• Subjects: Decision making; Eigenvalues; health decision making; Literacy; Medicare; Multiple choice; numeracy; Original Research; Psychology; Researchers; Studies; Validity
• ISSN: 2474-8307; 2475-6024; 2474-8307
• DOI: 10.3928/24748307-20190624-01

A person's ability to work with and understand numerical information (i.e., numeracy) is increasingly important in everyday health and other decision-making contexts. Several survey measures of numeracy have been developed to address this trend, including the widely used General Numeracy Scale (GNS), which is thematically focused on health decision-making and is assumed to measure a unidimensional construct of numeracy. The present research was designed to evaluate this proposed unidimensional structure of general numeracy, for which prior data have given mixed empirical support. Three samples completed the GNS, in different forms, and responses were analyzed in terms of underlying factor structure. We show that both one-factor and four-factor models of numeracy are plausible based on the GNS (Study 1), and then develop a multiple-choice version of the GNS (i.e., the MC-GNS) that demonstrates some increased clarity in factor structure due to the consistent response format (Study 2). A further study evaluated the convergent and discriminant validity of the MC-GNS (Study 3), finding it to be as good as or better than the prior scale. Additionally, the MC-GNS is easier for people to take, likely to be less stressful, and easier for practitioners to score. Collectively, this research identifies a problem with the GNS measure, develops improvements to help address this problem, and in the process creates a way to more easily measure numeracy in practical settings. . Numeracy is important across health contexts. Prevalent numeracy scales assumedly measure a single construct but empirical support for this is lacking. We find both one- and four-factor models are consistent with one scale and develop a revision that clarifies this structure without sacrificing validity. This revised numeracy scale is easier to administer and score, and therefore preferable in practical settings.