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). An 8-item short form of the written NUMi has also been developed and validated and is available on the main menu of this website.

A Computer Adaptive Test of the NUMi (NUMi CAT) has also been developed and is available in English and Spanish and can be accessed through the main menu of 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 is 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.