Table 1.

Definitions for Terms Used in Quality Measurement for Functional Status and Health-Related Quality of Life

Term	Definition
Quality indicator (process and outcome)	An agreed-upon process or outcome measure used to assess quality of care at the population level. Process includes health services that are provided, including screening, assessment, treatment, and follow-up; outcomes are end results for patients. Expressed as a percentage of the population, with a specified numerator and denominator.
Structural standard	A specific manner of organization-level activities that, when executed effectively, leads to improved outcomes. Referred to as Preferred Practice by National Quality Forum.
Measurement tool	Structured, specified instrument to collect information on a care process or outcome at the level of the individual, usually self-reported—can be used as information for a quality indicator at the population level. Example: Quality of life instrument (Medical Outcomes Study 12-item Short Form Survey).
Usability	Extent to which intended audiences can understand the results and find them useful for decision-making; meaningfulness of information. Sufficient variation in care is an important element so that indicators can differentiate between organizations.
Feasibility	Extent to which required data are readily available or can be captured without undue burden and can be implemented. Requires data to apply measure specifications and adequate sample size at the health plan or organizational level.
Validity	Correctly reflects quality of care provided, accurately identifying differences. Includes the need for specifications consistent with supporting evidence and statistically significant or clinically meaningful differences in performance.