Table 2. Framework for considering which patient characteristics to include in case mix adjustment

Methodological Considerations in Generating Provider Performance Scores

Guiding questionsExamples of patient characteristics
AgeSocioeconomic statusAdherence
Is the patient characteristic considered to be beyond control of providers?aYesYesControversial
Is the relationship between the characteristic and performance considered acceptable?aYes, for some performance measures (e.g., mortality rates)ControversialControversial
Include characteristic in case mix adjustment?Yes, for some performance measures ControversialControversial
As an alternative to case mix adjustment, present stratified results?A reasonable option, but no advantage over case mix adjustment Yes, may be a good alternativebStratification still controversialc

a. The answers to these questions are "value judgments" on which CVE stakeholders can attempt to achieve consensus. 

b. If stratified performance reports display scores on the same scale in each stratum, then performance disparities will be reported. However, if stratified reports display scores on different scales (e.g., a ranking within each stratum), then stratification will have no advantage over case mix adjustment. Both techniques will make performance disparities appear to vanish.

c. Like case mix adjustment, stratifying by adherence (i.e., separately reporting performance for "adherent" and "nonadherent" patients) eliminates the incentive to improve adherence.

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Page last reviewed September 2011
Internet Citation: Table 2. Framework for considering which patient characteristics to include in case mix adjustment: Methodological Considerations in Generating Provider Performance Scores. September 2011. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/professionals/quality-patient-safety/quality-resources/value/perfscoresmethods/perfsctab2.html