The NUMi was developed using Item Response Theory (IRT). An item bank (n=110) was developed based upon a theoretical model of health numeracy. The test was formed to reflect a range on content and difficulty and to reach high levels of discrimination. The 20-item written NUMi was validated against existing measures of health literacy, numeracy, and cognitive ability as described in the validation paper (Med Decis Making 2012;32:851-865). 

Future Plans

A Computer Adaptive Test of the NUMi (NUMi CAT) is under development and will soon be available through this website. The NUMi CAT is being evaluated as a screening test in the setting of the cancer treatment consultation. The study will test the hypothesis that a communication strategy tailored to the level of health numeracy will lead to improved communication and decision process outcomes.


The written NUMi has been translated and validated in Japanese (NUMi-J).  The NUMi CAT will be available in English and Spanish.   

Reference: Okamoto M, et al. Translation and Application of the Numeracy Understanding in Medicine Instrument in Japan.  Presented at the Society for Medical Decision Making Annual Meeting; Baltimore, MD; October 2013.

Grant Support
This work has been supported by the NCI 5RO1CA115954-3 and the American Cancer Society RSG-11-104-01-CPPB.