ABSTRACT
Introduction ............................................................................................................ 426 The Denition and Concept of Health ................................................................... 427
Why Measure Health? ....................................................................................... 428 Approaches to Measuring Health and Illness ........................................................ 428
Types of Measure .............................................................................................. 428 Mortality Data .............................................................................................. 428 Morbidity and Service-Use Data .................................................................. 429 Disability-Adjusted Life Years ..................................................................... 430 Subjective Health Measures ......................................................................... 430 Health-Related Quality of Life ..................................................................... 432
The Science of Health Status Measurement .......................................................... 432 Choice of an Instrument: Generic, Condition Specic or Patient Specic? ..... 433 Characteristics of Instruments ........................................................................... 434
Administration Method ................................................................................ 434 Scoring Method ............................................................................................ 435
Psychometric Properties of Standardized Instruments ...................................... 436 Conceptual and Measurement Models ......................................................... 437 Reliability ..................................................................................................... 437 Validity ......................................................................................................... 438 Responsiveness ............................................................................................. 439 Interpretation ................................................................................................ 439 Burden .......................................................................................................... 439 Alternative Forms of Instrument .................................................................. 439 Cultural and Language Adaptations ............................................................. 439
Conclusion .............................................................................................................440 Further Reading .....................................................................................................440 References ..............................................................................................................440
Health services must continually change to ensure that a population’s needs and expectations are met. The World Health Organization (WHO) identied the following aims for an evolving health service (World Health Organization 2010):
