Excel Video 124 demonstrates how to add a second y axis to a chart. In this example, we’re charting collection dollars and the percent of billed charges on the same chart. The collections each month are hundreds of thousands of dollars while the percentage of billed charges collected will never be greater than 1. Plotting both series on the same chart means you’ll never see the percentages until we make a few changes.
The trick is to highlight the percentage series and change the chart type to a line chart, then change the series to point to the secondary y axis (on the right side) instead of the primary y axis (on the left side). You can format the secondary y axis just like the primary y axis (we’ll change the number formatting in the Excel Video) and customize it any way you’d like.
Showing two pieces of information on the same chart saves report and dashboard space. It also helps show relationships between the two pieces of information. In this case, we can see the collection dollars are down while the percentage of billed charge is rising. One of several explanations could be that the clinic’s contract with the payer changed to a more restrictive network with higher reimbursement but fewer patients.
