National Vital Statistics System

About the Mortality Medical Data System

Historical Background

The National Center for Health Statistics (NCHS) began to develop the Mortality Medical Data System in 1967 to automate the entry, classification, and retrieval of cause-of-death information reported on death certificates. Mortality medical data is processed through four basic programs: Super-MICAR Data Entry, MICAR1, ACME2, and TRANSAX3.

  • SuperMICAR Automates the MICAR data entry process. This system is designed as an enhancement of the earlier PC-MICAR Data Entry System. Super-MICAR is designed to automatically encode cause-of-death data into numeric entity reference numbers.
  • MICAR Automates the multiple cause coding rules and assigns ICD codes to each numeric entity reference number.
  • ACME Automates the underlying cause-of-death coding rules. The input to ACME is the multiple cause-of-death codes (ICD) assigned to each entity (e.g., disease condition, accident, or injury) listed on cause-of-death certifications, preserving the location and order as reported by the certifier. ACME then applies the World Health Organization (WHO) rules to the ICD codes and selects an underlying cause of death.
  • TRANSAX Converts the ACME output data into fixed format and translates the data into a more desirable statistical form using the linkage provisions of the ICD. TRANSAX creates the data necessary for person-based tabulations by translating the axis of classification from an entity basis to a record basis.

An installation set was provided through data year 2011 online specifically for vital statistics offices in the jurisdictions. Updates to parts of the system and centralization of coding at the National Center for Health Statistics in 2010 brought an end to this largely decentralized approach to coding and processing mortality data.

1 Mortality Medical Indexing, Classification, and Retrieval

2 Automated Classification of Medical Entities

3 TRANSlation of Axis