Hello... 
I will certainly think of my 'favorite' fact but I cannot resist commenting on the one just posted.

It is not correct to state that people cannot do any of the tasks noted. A more appropriate way to say this is "people below level X have difficulty completing this task with accuracy and consistency" .

What is missing from this insight [and it is valuable measure and an important insight] is the critical finding from over 800 published studies that health materials are generally poorly written and designed.

so... this does lead to my favorite assertion taken from the IOM report:

Health literacy is a shared function of social and individual factors. page 4
or
Health literacy is a shared function of cultural, social, and individual factors. Both the causes and the remedies for limited health literacy rest with our cultural and social framework, the health and education system that serve it, and the interactions between these factors. page 32


in addition: 
The cost research is not firmly established nor uniformly accepted. It is not possible, for example, to differentiate between costs due to medical errors [errors made by professionals] and costs due to literacy related errors [errors made by patients]. I am very disquieted by the assumption that costs are due to patient error or to patient deficits. 

Rima

Rima E. Rudd, ScD, MSPH
Department of Society, Human Development & Health
Harvard School of Public Health
677 Huntington Avenue
Boston MA 02115
Phone: 617 432 1135
fax:     617 432 3123
web:    www.hsph.harvard.edu/healthliteracy
www.hsph.harvard.edu/sisterstogether