Communicative Numeracy in Type 2 Diabetes: Development and Validation of the CN12 Scale

Numbers have a role in the management of type 2 diabetes (T2D) in both day-to-day choices and discussions with partners. However, most numeracy measures focus on computation and provide little information about the ability to explain, verify, and adapt quantitative health information in interaction. We describe communicative numeracy as the ability to employ quantitative health information in conversation to enable shared understanding and collaborative action, guided by the integrative theory of communication work. Study 1 created and evaluated a pool of items and then surveyed 300 adults with T2D who lived with a romantic partner. The exploratory factor analysis yielded a 12-item Communicative Numeracy Scale (CN12) with three factors. Study 2 examined the retained structure in a second sample of 300 adults with T2D. Confirmatory factor analysis supported the retained three-factor organization of the items, while an additional bifactor analysis indicated that the CN12 total score should be treated as the primary score. CN12 showed small positive associations with subjective numeracy and diabetes self-efficacy and was essentially unrelated to general communication competence. After adjustment for age, socioeconomic status, education, and traditional numeracy measures, CN12 remained positively associated with diabetes self-efficacy. In an exploratory analysis, CN12 scores were positively associated with one self-report item measuring the frequency of diabetes-related number talk with partners. The findings support communicative numeracy as a measurable interactional resource in diabetes-related partner communication.