The results of health risk assessments (HRA) are often returned to patients using some form of summary score. The goal of this image was to make an abstract (and arbitrary) HRA score have more intuitive meaning.
This graph uses a very simple 4-category color scheme / gradient to make sure that people get a clear message about how good or poor their health risk assessment score is. Yet, the primary message is the number itself, which is placed centrally and colored to correspond to its risk category.
Note also that two key reference standards (average score and score if this person quit smoking) are provided to improve evaluation of the number.
With this graphic, people were most accurate in reporting which risk categories they fell into. This graphic also resulted in the lowest perceived difference that quitting smoking would make to the person's health, but the perceived difference is still quite large and seems the most accurate among this set of graphics. We recommend this graphic.