Making Health Data Understandable: 3 Tips for Using Numbers in Communication

Prepared by Samuel Mendez

Summary

As health communicators, we know the value of useful data. At the same time, we know it can be confusing. This tipsheet offers advice to elevate your health communication by making numbers more understandable. Start by focusing on 1 main message and 1 call to action. Figure out if you really need numbers to support them. If you do, use these 3 tips:

1. Explain what numbers mean in practical terms.
2. Use “X in 100” statements instead of percentages.
3. Use counts instead of complex math concepts.

With these tips, you’ll make the complex clear and give your audience insight into their health. Read on to see them in action.

Tip 1: Explain what numbers mean in practical terms.

Most people don’t measure weight, size, or distance every day. So, give them a familiar reference instead of just measured units. This involves a trade-off between precision and practicality. For example, describing what a serving of food looks like is less precise than stating its weight. But it’s also more realistic than expecting someone to weigh their food.

Giving numbers in practical terms might also involve specific brands or products. You can remind people you’re not promoting the products. They’re just common reference points.

Example: Serving size in practical terms

According to the USDA, one serving of hard cheese weighs 1.5 ounces. A serving of cheddar would be about the same size as 4 playing dice.

Learn how to judge whether your numbers have clear meanings

• Use Part C of the the CDC Clear Communication Index to judge whether your content explains what your numbers mean.

Tip 2: Use “X in 100” statements instead of percentages.

Most people don’t intuitively understand percentages. So, give them the info in a more understandable format. “66 out of 100 people” is close enough to “65.5% of people.” And it reminds your audience what a percentage means. It also rounds the statistic to avoid numbers that don’t make sense. Example: what is a fraction of a person? An “X in 100” statement also lends itself to an icon array, which offers easier and more precise readings than bar graphs or pie charts.

Example: Cancer risk as an “x in 100” statement

According to the National Cancer Institute, 41 out of 100 people in the US will be diagnosed with cancer at some point during their lifetime.

Learn how to make more icon arrays

• Use the University of Michigan’s Icon Array tool to make more graphics like these.

Tip 3: Use counts instead of complex math concepts.

Support your main message with counts rather than percentages, graphs, or risk statements. This way, your audience can focus on your main message rather than being distracted by an unfamiliar math concept. Note: this might involve editing your main point. Example: focus on why getting 8 hours of sleep helps people feel good, rather than numerically describing improvements in disease risk associated with adequate sleep.

To be sure, some messages require more complex math concepts. In these cases, ask yourself: are you available for follow-up questions? Can you verify your audience’s understanding? What’s the cost of a misunderstanding? Is your message format the best way to have this complex conversation?

If you must use a more complex math concept, pair it with a simpler one to help more people interpret the complex info. Use a concept as close to level 1 on this list as you can:

1. Counts (Example: “8 hours of sleep”)
2. Frequencies or percentages (Example: “41 in 100 people”)
3. Tables, graphs, or maps (Example: bar chart)
4. Relative values (Example: “a 5% change in weight”)
5. Relative Risk (Example: “Smokers are 2 times as likely…”)

Example: Streamlined COVID-19 data

The examples below use data from the same Kaiser Family Foundation report on Long COVID. We present them in order of complexity, from the least complex format to most complex. Each format makes it easier to highlight a different aspect of the data. You might decide to use several formats at once to present different kinds of takeaways. But the process of streamlining your data should also be a prompt to use less data. What is the minimum amount of data you need to support your point?

Least complex: Frequencies and counts

According to an analysis from the Kaiser Family Foundation, 11 in 100 transgender adults had Long COVID symptoms in March 2024. 9 in 100 cisgender women had Long COVID symptoms, as did 6 in 100 cisgender men. This means over 18 million American adults had Long COVID in March 2024.

More complex: Table (level 3 in the last above) and percentages (level 2)

	Cis Men	Cis Women	Trans Adults
Percent reporting Long COVID symptoms in March 2024	6%	9%	11%

Most complex: Risk statements (level 5 in the list above) and relative values (level 4)

In a March 2024 analysis by the Kaiser Family Foundation, cisgender women were 50% more likely than cisgender men to have Long COVID symptoms. Transgender adults were 83% more likely than cisgender men to have Long COVID symptoms

Learn how to streamline more numbers

• Read “Numeracy and Communication with Patients” for more examples of these math concepts in action

Takeaways

This tipsheet offers advice on making numbers clearer in health communication:

• Ask yourself whether you really need numbers to support your main message
• Explain numbers in practical terms
• Avoid percentages
• Choose simpler math concepts.

This tipsheet is part of a series on clear communication. It bridges knowledge from health literacy, web accessibility, marketing, and journalism to help you elevate your health communication. Combine your understandable numbers with clearer writing and accessible graphs and tables for even more impact.

This tipsheet was prepared by Samuel R. Mendez. It was reviewed by Amanda Yarnell and Elissa Scherer.