Table 17.3.b: A taxonomy of health status and quality-of-life measures adapted from Patrick and Erickson (Patrick 1993).

Measure

Strengths

Weaknesses

Types of Scores Produced

 

 

Single indicator number.

Global evaluation;

Useful for population.

May be difficult to interpret.

Single index number.

Represents net impact;

Useful for cost-effectiveness.

Sometimes not possible to disaggregate contribution of domains to the overall score.

Profile of interrelated scores.

Single instrument;

Contribution of domains to overall score possible.

Length may be a problem;

May not have overall score.

Battery of independentscores.

 

Wide range of relevant outcomes possible.

Cannot relate different outcomes to common measurement scale;

May need to adjust for multiple comparisons;

May need to identify major outcome.

Range of Populations and Concepts

 

 

Generic: applied across diseases, conditions, populations, and concepts.

 

Broadly applicable;

Summarizes range of concepts;

Detection of unanticipated effects possible.

May not be responsive to change;

May not have focus of patient interest;

Length may be a problem;

Effects may be difficult to interpret.

Specific: applied to individuals, diseases, conditions, populations, or concepts/domains.

More acceptable to respondents;

May be more responsive to change.

Cannot compare across conditions or populations;

Cannot detect unanticipated effects.

Weighting System

 

 

Utility: preference weights from patients, providers, or community.

Interval scale;

Patient or consumer view incorporated.

May have difficulty obtaining weights;

May not differ from equal weighting, which is easier to obtain.

Equal weighting: items weighted equally or from frequency or responses.

More familiar techniques;

Appears easier to use.

May be influenced by prevalence;

Cannot incorporate tradeoffs.