"This project has been funded in whole or in part with Federal funds from the National Library of Medicine, National Institutes of Health, Department of Health and Human Services, under Contract No. N01-LM-6-3503 with the University of Illinois at Chicago.” 

From the National Cancer Institute, Clear & Simple: Developing Effective Print Materials for Low-Literate Readers

From Doug Seubert, Health Communications Specialist, Marshfield Clinic, Wisconsin, several resources for improving readability through good design

Simply Put from the CDC

The Plain English Campaign from the UK provides several plain english guides.

The Health Literacy & Plain Language Resource Guide from Health Literacy Innovations, an extensive guide to plain language information.

Plain and Simple, the Health Literacy Project from Iowa provides extensive information including first-person stories on the challenges of poor health literacy and examples of simplified print health information.

Print Friendly Plain Language Principles and Thesaurus from the U.S. Health Resources and Services Administration, with particular application to HIPPA privacy notices.

The PRISM Readability Toolkit is a comprehensive resource that shows research teams how to create consent forms and other participant materials in plain language.  It was produced by the Project to Review and Improve Study Materials (PRISM) at the Group Health Center for Health Studies (CHS) is a non-proprietary, public-domain research institution within Group Health, a health care system based in Seattle, Washington. Suggested through the Comments function by Jessica Ridpath.  Thanks, Jessica.

From the VA's Consumer Health Library Panel

Doak, Cecilia Conrath, Leonard G. Doak, and Jane H. Root. Teaching Patients with Low Literacy Skills. Philadelphia: J.B. Lippincott, 1996.

Purcell-Gates, Victoria. Other People's Words: The Cycle of Low Literacy. Cambridge, Mass: Harvard University Press, 1995.

Zarcadoolas, Christina, Andrew F. Pleasant, and David S. Greer.
Advancing Health Literacy: A Framework for Understanding and Action. San Francisco, CA: Jossey-Bass, 2006.

A web style guide from Monash University (Au)

SMOG

• Try the free SMOG (Simple Measure of Gobbledygook) calculator
• Or a feature-rich option, Wordscount
• Detailed directions for using the SMOG to calculate by hand.

Fry Readability Formula

• The Fry Online

Other tools

• Readability Formulas

Pharmacy Related

USP Pictograms are standardized graphic images that help convey medication instructions, precautions, and/or warnings to patients and consumers.

Other

Picture Stories for Adult Health Literacy, from the center for Applied Linguistics