Morbidity and Mortality

Morbidity and mortality statistics provide information about the functional effects (morbidity) and death-producing (mortality) characteristics of a disease. These statistics are useful in terms of anticipating health care needs, planning of public education programs, directing health research efforts, and allocating health care dollars. Mortality or death statistics provide information about the trends in the health of a population. In most countries, people are legally required to record certain facts such as age, sex, and cause of death on a death certificate. Internationally agreed classification procedures (the International Classifi­cation of Diseases by the WHO) are used for coding the cause of death, and the data are expressed as death rates.¹⁰ Crude mortality rates (i.e., number of deaths in a given pe­riod) do not account for age, sex, race, socioeconomic sta­tus, and other factors. For this reason, mortality often is expressed as death rates for a specific population, such as the infant mortality rate. Mortality also can be described in terms of the leading causes of death according to age, sex,

race, and ethnicity. Among all persons 65 years of age and older, the five leading causes of death in the United States are heart disease, cancer, stroke, chronic obstructive lung disease, and pneumonia and influenza⁹ (Fig. 1-1). In 1997, for example, diabetes was the third leading cause of death among American Indians 65 years of age and older, the fourth leading cause of death among older Hispanic and black persons, and the sixth leading cause of death among older white persons and Asian Americans.¹¹

Morbidity describes the effects an illness has on a per­son's life. Many diseases, such as arthritis, have low death rates but have a significant impact on a person's life. Morbidity is concerned not only with the occurrence or incidence of a disease but also with persistence and the long-term consequences of the disease.