Age adjustment enhances the comparability of populations by controlling for the effects of their differing age compositions. It does this by applying age-specific rates in a population of interest to a standardized age distribution. The age-adjusted rates for two populations can be compared at the same point in time or the age-adjusted rates for the same population may be compared at different points in time. Age-adjusted rates in WISH are calculated using the direct method and use the Year 2000 Standard U.S. Population.
Injury-Related Emergency Department Visits
An "injury-related emergency department visit" is defined here as the treatment in a hospital emergency department and subsequent release of a patient whose visit was assigned an "External Cause of Injury Code" or "E-code" (See E-code definition below). Most of these patients have a principal diagnosis in the range 800-999 (ICD-9-CM).
Injury-Related Emergency Department Visit Rates
The rate of injury emergency department visits in a population is calculated by dividing the number of injury-related emergency department visits by the total population. It is expressed as the number of visits per 100,000 population. The rate may refer to injury-related emergency department visits in a specific group, or to injury-related emergency department visits from a specific cause, or to all injury-related emergency department visits in the entire population. The rate may be adjusted for the age composition of the group or it may be the observed (or "crude") rate. This module uses the patient's county of residence for the population base.
Total and Average Hospital Emergency Department Charges
Total and average charges include only the hospital's standard charges. They do not include any separate fees for physicians, anesthetists, and other professionals. They are not the "costs" actually paid to hospitals, since charges are often discounted by negotiation with insurers and other payers.
"E-code" or External Cause of Injury Code
The external underlying cause of injury is the way in which the person sustained the injury; how the person was injured; or the process by which the injury occurred. External causes for injuries have been coded by hospital medical records staff according to the International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) http://www.cdc.gov/nchs/icd.htm.
Manner or Intent of Injury
The E-code system captures both the external cause of an injury and the manner in which it occurred or the intent of the person causing it. Most injuries are the result of unintentional circumstances or events.