How to Calculate Relative Improvement

Absolute improvement and relative improvement are methods of finding out whether the quality of health care is improving. Quality of health care is measured using benchmarks, or standards of medical care that should be provided to a particular group of people or in a particular medical situation. Relative improvement can be calculated in two ways. The first way calculates improvement by taking into account the percentage of people who met the benchmark at the first time of measurement, the baseline. The second way takes into account the percentage of people who failed to meet the benchmark at the baseline.

Things You'll Need

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Instructions

• 1

  Collect data for the same benchmark at two points in time. For example, if you are the administrator of a health insurance plan and know that flu shots are recommended each year for people over the age of 64, you might collect data on the percentage of your members older than 64 who received flu shots in 2009 (baseline year) and 2010 (followup year).

• 2

  Calculate absolute improvement by looking at the difference in the percentage of people who met the benchmark in each of the two years. If 42 percent of people older than 64 received a flu shot in 2009, and 62 percent received a flu shot in 2010, the absolute difference (62 percent minus 42 percent) is 20 percentage points.

• 3

  Calculate the baseline failure rate. The baseline failure rate is the difference between the percentage of people who met the benchmark in 2009 (baseline) and 100 percent. If 42 percent of people older than 64 received a flu shot in 2009, subtract 42 percent from 100 percent. This difference is 58 percentage points, and is called the failure rate.

• 4

  In the first method of calculating relative improvement, take the absolute improvement (20 percentage points) and divide it by the baseline (2009) measure of the benchmark (42 percentage points). Relative improvement using this method is 47.6 percent. This method of calculating relative improvement takes into account the baseline measure of the benchmark.

• 5

  In the second method of calculating relative improvement, take the absolute improvement (20 percentage points) and divide it by the baseline failure rate (58 percentage points). Relative improvement using this method is 34.5 percent, rounded off. This method of calculating relative improvement takes into account the baseline failure rate, or the percentage of people who did not get medical care according to the benchmark in 2009.