Convert Time Format to Decimal Range

Case Study - Time to Hour Span for Pareto Chart

One hospital operating room was trying to determine how long it takes from the time a patient arrives until they enter the OR. They had the actual times, so they could have run a histogram using QI Macros, but wanted to categorize it as 0-1 hour, 1-2 hours, and so on.

The formula to convert time to an hour-span involves concatenating the hour with a dash (-) and some addition. So, 2 hours and 44 minutes (2:44) becomes 2-3.

Here's the Excel Formula to Convert Time to a Decimal Range:


View in Excel:


Once Completed, Use a PivotTable to Summarize the Data:

  1. Click on Cell C1 and use the QI Macros PivotTable Wizard to summarize the data:
  2. convert-time-decimals-pivot

  3. Next click and drag over A3 to B12 and then click on the QI Macros Pareto Chart.
  4. pareto-convert-time-to-hours-2

  5. Analyze the Pareto Chart for what it tells you.


Analyzing the Data

Based on my experience, I’d guess that patients in the 0-1 hour category probably came from the emergency room. Almost half, however, take 2-3 hours from arrival to the OR. If you've ever been a surgical patient, you know that the time spent waiting for surgery is like dog years - every minute seems like 10. From a patient standpoint, wouldn’t the hospital want to reduce all times from arrival to OR?

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