Use of plain language in participant-facing documents such as advertisements and consent forms helps to ensure non-scientific readers can understand the study’s purpose and procedures. We suggest the following approaches:

• Using words like “about” instead of “approximately”
• Describing blood draw amounts in both milliliters and teaspoons/tablespoons
• Using active voice instead of passive voice
• “Approximately 45 milliliters of blood will be collected via venipuncture,” can be appropriate for a medical journal. “We will draw about 3 tablespoons (45 milliliters) of your blood from a vein in your arm,” is better for a consent form.

Plain language resources and guidance are available at:

• Principles of plain language (U. S. General Services Administration)
• Plain Language Medical Dictionary (University of Michigan)
• Lay Language Glossary (Stanford University)
• Health Literacy in Clinical Research (Multi-Regional Clinical Trials Center)