Opioid Technical Notes for WISH

The United States transitioned from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) Classification System to the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) on October 1, 2015. Consequently, the way opioid-related hospital encounters are identified changed at this time to reflect ICD-10-CM codes. We have observed a larger than expected increase in the number of opioid-related hospital encounters as of October 1, 2015, which may be due to changes in the coding or could reflect a true increase in the number of opioid-related hospital encounters. Users should use caution in comparing data from 2015 and 2016 to previous years.

Language adapted from https://www.hcup-us.ahrq.gov/faststats/OpioidUseServlet

The unit of analysis is the hospital inpatient stay or an emergency department (ED) visit, not a person or patient. For example, if a patient visits the hospital three times in the same year, you would see three separate hospital stays or emergency department visits.

From 2005 to September 30, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields or first-listed external cause of injury field:

• 304.00-304.02: Opioid-type dependence (unspecified, continuous, episodic)
• 304.70-304.72: Combinations of opioid-type drug with any other drug dependence (unspecified, continuous, episodic)
• 305.50-305.52: Opioid abuse (unspecified, continuous, episodic)
• 965.00-965.02; 965.09: Poisoning by opium (alkaloids), unspecified; heroin; methadone; other opiates and related narcotics
• 970.1: Poisoning by opiate antagonists
• E850.0-E850.2: Accidental poisoning by heroin; methadone; other opiates and related narcotics
• E935.0-E935.2: Heroin, methadone, other opiates and related narcotics causing adverse effects in therapeutic use

Starting October 1, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields:

• F11 series: Opioid-related disorders (except F11.21)
• T40 series: Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics (hallucinogens), with a seventh digit indicating initial or subsequent encounter, with a sixth digit indicating unintentional, intentional self-harm, assault or undetermined intent
  • 0X1, 0X2, 0X3, 0X4, 0X5: Poisoning by, adverse effect of and underdosing of opium
  • 1X1, 1X4: Poisoning by and adverse effect of heroin
  • 2X1, 2X4, 2X5: Poisoning by, adverse effect of and underdosing of other opioids
  • 3X1, 3X4, 3X5: Poisoning by, adverse effect of and underdosing of methadone
  • 4X1, 4X4, 4X5: Poisoning by, adverse effect of and underdosing of other synthetic narcotics
  • 601, 604, 605: Poisoning by, adverse effect of and underdosing of other and unspecified narcotics
  • 691, 694, 695: Poisoning by, adverse effect of and underdosing of other narcotics opioid poisoning (any opioid)

From 2005 to September 30, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields or first-listed external cause of injury field:

• 965.00-965.02; 965.09: Poisoning by opium (alkaloids), unspecified; heroin; methadone; other opiates and related narcotics
• E850.0-E850.2: Accidental poisoning by heroin; methadone; other opiates and related narcotics

Starting October 1, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields:

• T40 series: Poisoning by narcotics and psychodysleptics (hallucinogens), with a seventh digit indicating initial or subsequent encounter; with a sixth digit indicating unintentional, intentional self-harm, assault or undetermined intent
  • 0X1, 0X2, 0X3, 0X4: Poisoning by opium
  • 1X1, 1X2, 1X3, 1X4: Poisoning by heroin
  • 2X1, 2X2, 2X3, 2X4: Poisoning by other opioids
  • 3X1, 3X2, 3X3, 3X4: Poisoning by methadone
  • 4X1, 4X2, 4X3, 4X4: Poisoning by other synthetic narcotics
  • 601, 602, 603, 604: Poisoning by other and unspecified narcotics
  • 691, 692, 693, 694: Poisoning by other narcotics

From 2005 to September 30, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields or first-listed external cause of injury field:

• 965.00; 965.02; 965.09: Poisoning by opium (alkaloids), unspecified; methadone; other opiates and related narcotics
• E850.1-E850.2: Accidental poisoning by methadone; other opiates and related narcotics

Starting October 1, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields:

• T40 series: Poisoning by narcotics and psychodysleptics (hallucinogens); with a seventh digit indicating initial or subsequent encounter; with a sixth digit indicating unintentional, intentional self-harm, assault or undetermined intent
  • 0X1, 0X2, 0X3, 0X4: Poisoning by opium
  • 2X1, 2X2, 2X3, 2X4: Poisoning by other opioids
  • 3X1, 3X2, 3X3, 3X4: Poisoning by methadone

From 2005 to September 30, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields or first-listed external cause of injury field:

• 965.01: Poisoning by heroin
• E850.0 Accidental poisoning by heroin

Starting October 1, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields:

• T40 series: Poisoning by narcotics and psychodysleptics (hallucinogens); with a seventh digit indicating initial or subsequent encounter; with a sixth digit indicating unintentional, intentional self-harm, assault or undetermined intent
  • 1X1, 1X2, 1X3, 1X4: Poisoning by heroin

From 2005 to September 30, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields or first-listed external cause of injury field:

• 304.00-304.02: Opioid-type dependence (unspecified; continuous; episodic)
• 304.70-304.72: Combinations of opioid-type drug with any other drug dependence (unspecified; continuous; episodic)
• 305.50-305.52: Opioid abuse (unspecified; continuous; episodic)

Starting October 1, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields:

• F11 series: Opioid-related disorders (except F11.21)

From 2005 to September 30, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields or first-listed external cause of injury field:

• E935.0-E935.2: Heroin, methadone, other opiates and related narcotics causing adverse effects in therapeutic use

Starting October 1, 2015, defined as inpatient hospital stay or emergency department visit with any of the following ICD-9-CM codes in the principal diagnosis or any contributing diagnosis fields:

• F11 series: Opioid-related disorders (except F11.21)
• T40 series: Adverse effect of narcotics and psychodysleptics (hallucinogens); with a seventh digit indicating initial or subsequent encounter
  • 0X5: Adverse effect of opium
  • 2X5: Adverse effect of other opioids
  • 3X5: Adverse effect of methadone
  • 4X5: Adverse effect of other synthetic narcotics
  • 605: Adverse effect of other and unspecified narcotics
  • 695: Adverse effect of other narcotics

The payer who is expected by the hospital to be the primary payer of the inpatient stay. This payer will be the first one billed. There also may be a secondary payer.

The query uses the Underlying Cause of Death (UCOD) field from the death certificate to identify drug overdose as:

• Drug overdose deaths involving opioids. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14)
• All drug overdose deaths:
  • Deaths with any of the following ICD-10 codes as an underlying cause of death:
    • X40-X44: Accidental poisonings by drugs
    • X60-X64: Intentional self-poisoning by drugs
    • X85: Assault by drug poisoning
    • Y10-Y14: Drug poisoning of undetermined intent
  • Selecting the specific drug involved in the overdose
  • Deaths with any of the following ICD-10 codes as an underlying cause of death:
    • X40-X44: Accidental poisonings by drugs
    • X60-X64: Intentional self-poisoning by drugs
    • X85: Assault by drug poisoning
    • Y10-Y14: Drug poisoning of undetermined intent
  • AND with any of the following ICD-10 contributing cause of death codes:
    • T40.0: Opium
    • T40.1: Heroin
    • T40.2, T40.4: Natural and semisynthetic opioids, other than methadone
    • T40.2: Synthetic opioids (proxy for Fentanyl)
    • T40.5: Cocaine
    • T40.6: Other and unspecified narcotic
    • T42.4: Benzodiazepines
    • T43.6: Psychostimulants – including Amphetamine, Ritalin, Meth- Exclude Cocaine

Drug overdose deaths. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14)

Drug overdose deaths involving any opioid. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14) and a contributing cause of death T400 (opium), T401 (heroin), T402 (natural and semisynthetic opioid), T403 (methadone), T404 (synthetic opioid other than methadone), or T406 (other and unspecified narcotic)

Drug overdose deaths involving prescription opioids. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14) and a contributing cause of death T402 (natural and semisynthetic opioid), T403 (methadone), T404 (synthetic opioid other than methadone)

Drug overdose deaths involving heroin. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14) and a contributing cause of death T401 (heroin)

Drug overdose death involving synthetic opioids. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14) and a contributing cause of death T404 (synthetic opioid/fentanyl)

Drug overdose death involving benzodiazepines. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14) and a contributing cause of death T424 (benzodiazepines/valium)

Drug overdose death involving cocaine. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14) and a contributing cause of death T405(cocaine)

Drug overdose death involving psychostimulants. Defined as ICD-10 code indicating drug poisoning as an underlying cause of death (X40-X44, X60-X64, X85, or Y10-Y14) and a contributing cause of death T436 (psychostimulants/amphetamine)

Age adjustment controls for the effect of different age distributions within a population, which helps make rates between those populations more comparable. 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 are based on the year 2000 Standard U.S. Population.

The rate is calculated by dividing the number of discharges (hospital encounters query) or deaths (drug overdose deaths query) per year by the population. It is usually expressed as the number of injuries per 100,000 population. The rate may refer to a specific group depending on query selections. 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. Please see the WISH population methods documentation for more detail.