Figure 9. How the number of observations affects uncertainty about the "true" average performance

Methodological Considerations in Generating Provider Performance Score

Two graphs showing effect of number of observations. In the first, only four observations are shown, with an average of 60. There is a greater range of uncertainty about average performance, with scores going from 48 to 80. The second graph shows 16 observations, with an average of 60. The range of uncertainty about average performance is smaller. Although the scores range from 40 to 80, more observations are centered around the mean.

Current as of September 2011

Internet Citation: Figure 9. How the number of observations affects uncertainty about the "true" average performance: Methodological Considerations in Generating Provider Performance Score. September 2011. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/professionals/quality-patient-safety/quality-resources/value/perfscoresmethods/perfscfig9.html