National Center for Health Statistics

Text Analysis of Death Certificate Records to 

Ascertain Drugs Involved in Deaths in the 

National Vital Statistics System

Merianne Rose Spencer1, Brigham A. Bastian2, and Margaret Warner2

Division of Analysis and Epidemiology1, Division of Vital Statistics2

National Center for Health Statistics

Government Advances in Statistical Programming (GASP) Workshop

Monday, September 23, 2019
Introduction: NCHS and NVSS

 National Center for Health Statistics (NCHS) provides

statistical information that guides actions and policies 

to improve the health of the American people

 National Vital Statistics System (NVSS) encompasses 

the processing and coding of birth and death 

certificate records from 57 jurisdictions*

– Cause-of-death (ICD-10) codes are assigned to 

death data received by jurisdictions at NCHS

– Data are coded, processed and then 

disseminated for health statistics, surveillance 

and research

*50 states, New York City, District of Columbia and 5 US territories (American 

Samoa, Guam, Norther Marianas, Puerto Rico, and Virgin Islands)
Data Source: Death Certificate

Demographic information 

Completed by the funeral director using 

information from the best qualified person: 

spouse, parent, child, another relative, or other 

person who has knowledge of the facts

Medical information

For natural causes, completed by attending 

physician, nurse practitioner, ph┞sician’s assistant 

For sudden and unexplained deaths, completed by 

medical examiner, coroner, Justice of the Peace 

Demographic information
U.S. Standard Death Certificate:

Cause-of-Death Section

Referred to as the literal text:

 the information written by 

the medical certifier on the 

cause, manner, 

circumstances, and other 

factors contributing to the 

death

– Part I – Chain of events that 

directly caused the death

– Part II – Significant conditions 

contributing to death

– Box 43 – Describe how the injury 

occurred
Drug Overdose Death Rates, United States, 1999-2017

0

1

2

3

4

5

6

7

Deaths per 100,000 standard population

1999 2001 2003 2005 2007 2009 2011 2013 2015 2017

T40.2

Natural and 

semisynthetic 

opioids 

T40.4

Synthetic opioids other than 

methadone 

T40.1

Heroin

T40.3

Methadone

SOURCE: National Center for Health Statistics. National Vital Statistics System Mortality File, 1999-2017.
Drug Overdose Death Rates, United States, 1999-2017

0

1

2

3

4

5

6

7

Deaths per 100,000 standard population

1999 2001 2003 2005 2007 2009 2011 2013 2015 2017

T40.2

Natural and 

semisynthetic 

opioids 

T40.4

Synthetic opioids other than 

methadone 

T40.1

Heroin

T40.3

Methadone

SOURCE: National Center for Health Statistics. National Vital Statistics System Mortality File, 1999-2017.
Examples of common drugs found on death certificates 

without specific ICD-10 code

Opioids

• Fentanyl

• Fentanyl analogs

• Oxycodone

• Hydrocodone

• Morphine

• Hydrocodone

• Tramadol

Stimulants

• Methamphetamine

• MDMA

Benzodiazepines

• Alprazolam

• Diazepam

• Clonazepam

3-Methylfentanyl

4-ANPP

4-MeO-Butyrylfentanyl

Acetylfentanyl

Acrylfentanyl

Acryloylfentanyl

Alfentanil

Butyrylfentanyl

Carfentanil

Despropionyl-fentanyl

Furanyl fentanyl

Methylfentanyl

Para-fluorobutyrl-fentanyl

Para-fluoroisobutyrylfentanyl

P-Fluoro-butyrylfentanyl

Remifentanil

Sufentanil

...
Methods to Identify Specific Drugs on Death Records

 Collaboration between NCHS and FDA

 Developed methods to analyze literal text for mentions of specific drugs 

– Preprocessed text (e.g., remove stop words, special characters)

– Examined and reviewed string terms and phrases

– Categorized terms into categories (i.e., principal variants)

– Considered conte┝t ふe.g., さhistor┞ ofざ, さinsulin-dependentざぶ

 Referred to as the Drugs Mentioned with Involvement (DMI) 

methodology1

1 Drugs Mentioned with Involvement (DMI) methodology : https://www.cdc.gov/nchs/data/nvsr/nvsr65/nvsr65_09.pdf
Top drugs involved in drug overdose deaths, 2011 and 2016

2011 2016

Rank Referent drug

# of 

deaths Referent drug

# of 

deaths

1 Oxycodone 5,587 Fentanyl 18,335 

2 Cocaine 5,070 Heroin 15,961 

3 Heroin 4,571 Cocaine 11,316 

4 Methadone 4,545 Methamphetamine 6,762 

5 Alprazolam 4,066 Alprazolam 6,209 

6 Morphine 3,290 Oxycodone 6,199 

7 Hydrocodone 3,206 Morphine 5,014 

8 Methamphetamine 1,887 Methadone 3,493 

9 Diazepam 1,698 Hydrocodone 3,199 

10 Fentanyl 1,662 Diazepam 2,022 

Selected Results

0

1

2

3

4

5

6

7

8

9

10

2011 2012 2013 2014 2015 2016

Deaths per 100,000 standard population

Age-adjusted rates for drug overdose deaths involving 

fentanyl, by sex: United States, 2011-2016

Females

Males

SOURCE: Spencer MR, Warner M, Bastian BA, et al. Drug overdose deaths 

involving fentanyl, 2011-2016. Natl Vital Stat Rep. 2019 Mar;68(3):1-19. SOURCE: Hedegaard H, Bastian BA, Trinidad JP, Spencer MR, Warner M. Drugs 

most frequently involved in deaths: United States, 2011-2016. Natl Vital Stat 

Rep. 2018 Dec;67(9):1-14.
Considerations and Next Steps

 Literal text analyses can enable researchers to report with more 

granularity, the specific drugs involved in deaths

 Challenges

– Identification of specific drugs is dependent on testing, interpretation and 

reporting by death certifiers

– Temporal changes in reporting of the specific drugs can impact trends analyses

 Future steps

– Automate these processes (e.g., machine learning), while recognizing 

that we must also identify terms that appear a small number of times
Questions?

Merianne Rose T. Spencer, M.P.H.

Epidemiologist

Division of Analysis and Epidemiology

National Center for Health Statistics

301-458-4377 | kvd1@cdc.gov

Brigham A. Bastian, B.S.

Statistician (Demography)

Division of Vital Statistics

National Center for Health Statistics

301-458-4517 | xcb7@cdc.gov

Margaret Warner, Ph.D.

Injury Epidemiologist

Division of Vital Statistics

National Center for Health Statistics

301-458-4556 | mmw9@cdc.gov

The findings and conclusions of this report are those of the authors and do not necessarily represent the official position of the 

Centers for Disease Control and Prevention.