UNDERSTANDING MORBIDITY CHANGE

Attempts to assess morbidity-illness, disability, and other compromised states of well-being-have grown in importance as life expectancy increases and mortality declines to very low levels in many populations. Morbidity measures are of two fundamental types, self-perceived and clinically observed, and different morbidity indicators may capture entirely different aspects of illness and health. The authors develop an approach to morbidity definition and measurement, review specific methods, and present a framework for classifying different types of morbidity indicators. They examine various approaches to the interactions between morbidity and mortality change, illustrating these with selected data from India, the United States, and Ghana.