Development and validation of a Spanish diabetes-specific numeracy measure: DNT-15 Latino

Abstract

Background: Although deficits in health literacy and numeracy have been described among Latinos, the impact of low numeracy on diabetes outcomes has not been studied. Study objectives were (1) to establish the reliability and validity of a 15-item Spanish, diabetes-specific numeracy measure (Diabetes Numeracy Test [DNT]-15 Latino) and (2) to examine the relationship between diabetes-specific numeracy and diabetes-related outcomes among a sample of Latino adults with diabetes.

Methods: Data collection included patient demographics, health literacy, general numeracy, diabetes-specific numeracy, acculturation, self-efficacy, self-care behaviors, and most recent glycosylated hemoglobin (HbA1c).

Results: Participants (n=144) were on average 47.8 years old (SD=12.1). The majority were female (62%), uninsured (81%), and of Mexican nationality (78%) and reported low levels of acculturation (96%). The DNT-15 Latino had high internal reliability (Kruder-Richardson 20=0.78). The DNT-15 Latino demonstrated construct validity, correlating with measures of health literacy (ρ=0.291), general numeracy (ρ=0.500), education (ρ=0.361), and income (ρ=0.270) (P<0.001 for each). The DNT-15 Latino was significantly associated with acculturation but unrelated to self-efficacy, self-care behaviors, insulin use, and HbA1c.

Conclusions: The DNT-15 Latino is a reliable and valid measure of diabetes-specific numeracy for Latino patients with diabetes; however, additional studies are needed to further explore the association between diabetes-specific numeracy and acculturation and their impact on diabetes-related outcomes for Latinos.