Mortality in Correctional Institutions: ICD-10 Diagnosis Codes for Natural Deaths Occurring in State Prison or Local Jail Custody, 2000-2019 (ICPSR 38671)

1. The ICD-10 codes presented in this collection are diagnosis codes, not procedure or billing codes, and as previously stated, should not be interpreted as the sole medical condition suffered by the decedent at the time of death. ICD-10 diagnosis codes consist of a letter followed by a 2-digit number that can range from 00 to 99. Additional numerical digits after the first two digits represent modifications or specifications to the condition designated by the first two digits, and are offset by a decimal. The ICD-10 codes in the MCI data are presented without decimals. If the MCI ICD-10 diagnosis code consists of a letter and a 2-digit number, there were no modifications or specifications associated with that condition in the text provided by the respondent. For 3- and 4-digit numbers, users should place the decimal point between the second and third number. For example, C22, C220, C223, C227, and C229 would all refer to a malignant neoplasm of the liver, but the additional digits were assigned when a respondent gave greater detail: C22.0 refers to liver cell carcinoma; C22.3 refers to angiosarcoma of the liver; C22.7 refers to other specified carcinomas of the liver; and C22.9 refers to malignant neoplasm of the liver which is not specified as primary or secondary.

2. Prior to 2015, only natural or illness deaths consistently were assigned ICD-10 diagnosis codes in the MCI collection. Unnatural deaths, including suicide, homicide, accidental injury and accidental intoxication, were assigned ICD-10 codes sporadically if enough descriptive detail was included on the individual death record submitted to BJS, and the nosologist was familiar with the ICD-10 diagnosis code. Similarly, deaths ultimately ruled to be of unknown cause received ICD-10 codes describing any medical detail prison or jail repsondents provided.

   From 2015 to 2019, nosologists coded all deaths with ICD-10 codes regardless of cause, although the level of detail varied based on what text was provided by the respondent (for example, many accidental intoxication deaths were coded as T50.9 - Poisoning by other and unspecified drugs, medicaments, and biological substances). While the ICD-10 diagnosis codes are provided on all records to which they were assigned during the MCI collection, BJS was specifically concerned with the medical coding of illness deaths, and data users should concentrate on analyses of ICD-10 codes for these decedents, as opposed to those who died by unnatural causes.

   The ICD-10 classification manual had a number of updates, culminating in a 2019 version. In some cases, ICD-10 diagnosis codes assigned to MCI decedents in the early years of the collection may no longer be found in the 2019 version. BJS suggests using Google to look for the letter and number combination to see whether earlier ICD-10 manual versions used the code listed.

3. Users interested in looking up ICD-10 diagnosis codes can refer to the Centers for Disease Control or the World Health Organization. Note that some ICD-10 codes may have fallen out of use in in more recent versions of the ICD-10 manual.

Local jail facilities and state departments of corrections

2023-05-15 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

• Created variable labels and/or value labels.
• Checked for undocumented or out-of-range codes.