Adaptation and validation of a measure of health literacy in Taiwan: The Newest Vital Sign

BACKGROUND: Health literacy (HL) refers to the ability to obtain, read, understand, and use basic health care information required to make appropriate health decisions and follow instructions for treatment. The Newest Vital Sign (NVS) is an instrument developed for assessing aspects of HL relevant to reading and numeracy skills. This study aimed to develop a traditional Chinese version of the NVS (NVS-TC) and assess its feasibility, reliability, and validity in Taiwanese patients with type 2 diabetes. METHODS: The original NVS was translated into traditional Chinese in accordance with established guidelines. A cognitive testing procedure was subsequently performed to evaluate the ease of understanding and acceptability of the test in 30 patients with diabetes. Thereafter, a quantitative survey (N = 232) was administered for validating the NVS-TC against the accepted standard tests of HL and participant education level. RESULTS: The internal consistency (Cronbach's α) was 0.76. In accordance with a priori hypotheses, we found strong associations between the NVS-TC and objective HL and weaker associations between the NVS-TC and subjective HL. The known group validity of the NVS-TC was demonstrated through multivariate regression analyses, which showed that educational differences in the NVS-TC scores remained significant after adjustment for age, gender, and working in healthcare. CONCLUSIONS: The results suggest that the NVS-TC is a reliable and valid tool that facilitates international comparable HL research in Taiwan. The NVS-TC can be used to investigate the role of HL in health care and can be easily incorporated into daily clinical practice for diabetes management.