Psychometric Properties of the Iranian Version of the Diabetes Numeracy Test‑15

Abstract

Background: Low health literacy (HL) of patients has obtained more attention as a risk factor for poor adherence to treatment and adverse outcomes in chronic disease’s management particular in diabetes care. Diabetes Numeracy Test‑15 (DNT‑15) has been developed specifically for this purpose. The objective of the current study is to evaluate psychometric properties of Iranian (Persian) version of the DNT‑15.

Methods: The shortened version of the DNT (15‑items) was completed by 120 patients with diabetes. The Kuder–Richardson Formula 20 for internal consistency was conducted. Content
validity, criterion‑related validity, and construct validity were also evaluated.

Results: The average score on the DNT was 72% and took an average of 25 minutes to complete. The DNT‑15 had a very good internal reliability (KR‑20 = 0.90) and also content validity (content validity ratio: 089 and content validity index: 0.86).

Conclusions: The DNT‑15 (Persian version) is a reliable and valid measure of diabetes‑related numeracy skills for Iranian 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 in Iranian population.

Keywords: Diabetes, health literacy, Iran, validity and reliability