Pie Charts Hurt Your Outcomes Data | Pros and Cons of Pie Charts

Pros and Cons of Pie Charts

Everyone loves pie. It’s a staple at many holiday and family dinners due to its classic simplicity. Similarly, pie charts are a classic choice in graphs to demonstrate parts against the whole. The structure of a pie chart is inherently associated with percentages as we have all perfected the skill of calculating the amount of pizza or apple pie left at a glance. They are also a good choice when looking to compare select pieces of data. But if used incorrectly, they could misrepresent your data.

The following pros and cons can help you decide when a pie chart is right for you. 

Having the Right Ingredients

Behavioral Health leaders are often asked to present to boards, funders, and community stakeholders on the progress of their organization. When you do, you need to effectively present the outcomes data you’ve collected to describe your clinic. Pie charts can be a helpful presentation tool if used appropriately.

When deciding whether to use a pie chart, you must understand what type of data you are working with and the pros and cons of pie charts. While a viable visual to use, they are only effective with certain types of data.

Pro: Easy to See Large Disparities in Data

Pie charts are very effective when showing data where there is a large disparity between two units. The example below shows a pie chart that records the number of progress notes that are billable compared to non-billable. There is a large difference between the two data units which makes the pie chart the ideal choice for this data.

Large Disparities

Pro: Can Emphasize Data When There Are Only a Few Units  

When deciding whether to use a pie chart, you need to consider how many data units you are comparing. Pie charts can emphasize data when there are only a few units. In the example below, the pie chart has categorized the patients by gender. The pie chart allows the viewer to quickly see that there are slightly more male patients than female patients, but that it is almost an even split.

A Few Pieces of Data

Con: Cannot Compare More Than A Few Pieces of Data

However, pie charts are not a good option for comparing more than a few pieces of data. With too many pieces of data, it is hard for the viewer to distinguish among the different units. In this case, many of the data units are smaller and harder to see as well. The example below compares progress notes by type. Because there are so many units, it is hard to read all of them and see what percent each is representing. This data would be better displayed as a bar graph.  

Too Many Pieces of Data

Con: Unhelpful When Observing Trends Over Time

Pie charts are not a good selection for comparing data over time. When considering the visual aspect of it, it is hard for the eye to fully understand the changes when looking at a circle. The example below shows monthly payment and write-off amounts represented in a pie chart. Because it is a pie chart, it is hard to see whether the organization has improved or declined in this area. Additionally, there are multiple data units which makes it hard to see the value of each wedge.

Trends Over Time Pie Chart

The same data is represented again in a line graph. In this example, you can see how much easier it is to track the organization’s monthly payment and write-off amounts. Your eye can easily follow the changes over the 8-month period.

Trends Over Time Line Graph.png

Have Your Pie and Eat It Too

The goal of any data presentation should be to select the methods that will show it off the best and lead your viewers to the conclusion you want them to reach. TenEleven’s Behavioral Health Dashboards can help you to craft the perfect pie chart.  Now that you know the pros and cons of pie charts, you’ll be able to use them effectively to frame your outcomes data in its best light.

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Topics: Clinical Practice, Industry Insights