WISH Mortality Module Definitions

Age adjustment

Age adjustment (PDF) is the application of age-specific rates in a population of interest to a standardized age distribution. It enhances the comparability of populations by controlling for the effects of their differing age compositions. The age-adjusted rate for a population of interest can be compared to that of a different age-adjusted population at the same point in time or the same population at a different point in time. Age-adjusted rates in WISH are calculated using the direct method based on the year 2000 U.S. standard population.

Causes of death—broad groups

Underlying causes of death grouped into 50 categories defined by the National Center for Health Statistics. These broad groups condense the more detailed 113 categories by creating more general disease groups and by combining vaguely defined "other," "not elsewhere classified," and "unspecified" causes into an "all other" category.

Causes of death—detailed groups

Underlying causes of death grouped into 113 categories by the National Center for Health Statistics. These 113 categories are consolidated from the tenth revision of the International Classification of Diseases (ICD-10) coding structure. They replace the ICD-9 list of 72 selected causes of death used from 1979 through 1998.

Deaths by race

For this query tool, prior to 2013, deaths where race was coded as Other, Unknown or Multiple were assigned to White, the most prevalent overall category. Beginning in 2013, decedents with multiple races reported were recoded to their most prevalent race. For example, a decedent reported as White and Black was recoded to White, and one reported as Black and Asian was recoded to Black. As with previous years, deaths where race was coded as Other or Unknown continue to be assigned to the White category.

This coding change had a minimal effect. Using the previous method, the percentages of deaths by race in 2013 were 93.69% White, 4.81% Black, 0.78% American Indian/Alaska Native, and 0.71% Asian. Under the new method, the percentages were 93.67% White, 4.83% Black, 0.78% American Indian/Alaska Native, and 0.72% Asian.

Mortality rate

The mortality rate is calculated by dividing the number of deaths per year by the population. It is usually expressed as the number of deaths per 100,000 population. The rate may refer to deaths in a specific group, or to deaths from a specific cause, or to all deaths in the entire population. The rate may be adjusted for the age composition of the group (see "age adjustment," above) or it may be the observed (or "crude") rate.

Rates and population

The population estimates used as denominators for the mortality rates in WISH from 2010+ (as well as 1990 and 2000) are drawn from the estimates produced by the U.S. Census Bureau. Population estimates for other years prior to 2010 (i.e., 1991-1999, 2001-2009) were created by blending population estimates produced by the Wisconsin Department of Administration with bridged race estimates from the Census Bureau and the National Center for Health Statistics.

Underlying cause of death

The underlying cause of death is defined by the World Health Organization (WHO) as the disease or injury that initiated the train of events leading directly to death, or the circumstances of the accident or violence which produced the fatal injury. Under international rules for selecting underlying cause from the reported conditions, every death is attributed to one underlying cause based on information reported on the death certificate.

Causes for deaths that occurred in 1999 and later have been coded according to the International Classification of Diseases, Tenth Revision (ICD-10). Causes of death were coded using the International Classification of Diseases, Ninth Revision (ICD-9) for deaths occurring in 1979-1998.

Years of potential life lost (YPLL)

An estimate of premature mortality, defined as the number of years of life lost among persons who die before age 75. YPLL is the sum of the differences between age 75 and the age at death for everyone who died before age 75.