Drug-Induced Deaths — United States, 1999–2010

Karin A. Mack, PhD

National Center for Injury Prevention and Control, CDC

Corresponding author: Karin A. Mack, Division of Analysis, Research, and Practice Integration, National Center for Injury Prevention and Control, CDC. Telephone: 770-488-4389; E-mail: kim9@cdc.gov.

Introduction

Drug-induced deaths include all deaths for which drugs are the underlying cause (1), including those attributable to acute poisoning by drugs (drug overdoses) and deaths from medical conditions resulting from chronic drug use (e.g., drug-induced Cushing's syndrome). A drug includes illicit or street drugs (e.g., heroin and cocaine), as well as legal prescription and over-the-counter drugs; alcohol is not included. Deaths from drug overdose have increased sharply in the past decade. This increase has been associated with overdoses of prescription opioid pain relievers, which have more than tripled in the past 20 years, escalating to 16,651 deaths in the United States in 2010 (2). Most drug-induced deaths are unintentional drug poisoning deaths, with suicidal drug poisoning and drug poisoning of undetermined intent comprising the majority of the remainder (3).

This drug-induced deaths analysis and discussion that follows are part of the second CDC Health Disparities and Inequalities Report (CHDIR) (3). The 2011 CHDIR (4) was the first CDC report to assess disparities across a wide range of diseases, behavioral risk factors, environmental exposures, social determinants, and health-care access. The topic presented in this report is based on criteria that are described in the 2013 CHDIR Introduction (5). This report provides more current information to what was presented in the 2011 CHDIR (3). The purpose of this drug-induced deaths analysis is to raise awareness of disparities by age, gender, racial/ethnic and/or geographic differences, and to prompt actions to reduce disparities.

Methods

To determine differences in the prevalence of drug-induced deaths by sex, race/ethnicity, age, and geographic region in the United States, CDC analyzed 2010 data from the mortality component of the National Vital Statistics System (NVSS). To examine patterns of drug-induced death rates by age group and race/ethnicity, NVSS data from 1999 through 2010 were aggregated because limited sample sizes are available for any single year for certain groups.

Death certificates provide information on the decedent's age, sex, race, ethnicity, and geographic region. They do not provide information on decedent income, disability, or language spoken at home. Race is categorized as white, black, American Indian/Alaska Native, or Asian/Pacific Islander. Ethnicity was categorized as Hispanic or non-Hispanic. Geographic location is categorized as Northeast, Midwest, South, and West.* Adverse effects from drugs taken as directed and infections resulting from drug use are not included.

The number of drug-induced deaths are presented and unadjusted (crude) drug-induced death rates per 100,000 population are calculated for 2010 by age, racial/ethnic group, sex, and geographic region (based on the U.S. Census 2010 population survey) (Table). The 95% confidence intervals (CIs) for unadjusted drug-induced death rates are based on ≥100 deaths and were calculated using a normal approximation; CIs based on <100 deaths were calculated using a gamma method. (Additional information is available from Vital Statistics of the United States: Mortality, 1999 Technical Appendix, available at http://wonder.cdc.gov/wonder/sci_data/mort/mcmort/type_txt/mcmort05/techap99.pdf).

Results

During 2010 (the year in which the latest national NVSS mortality data are available), a total of 40,393 drug-induced deaths occurred in the United States. The majority of drug-induced deaths were unintentional 74.3%; remainder: 13.1%; suicidal drug poisoning; 7.3% drug poisoning of undetermined intent; 5.1% mental and behavioral disorders from drug use; <1% homicide; <1% medical conditions from chronic drug use. Drug-induced mortality was highest among persons aged 40–49 years (25.1) (Table). Rates for males exceeded those for females aged ≥10 years. Rates were lowest in the Northeast region of the United States (11.6), and the largest percentage of cases was in the South (38.2%). Non-Hispanic whites accounted for 82.1% of all 40,393 drug-induced deaths. The highest rates were among American Indians/Alaska Natives (17.1) and non-Hispanic whites (16.6).

During 1999–2010, drug-induced death rates by race/ethnicity and age group demonstrated varying patterns by racial/ethnic group, although the highest rate occurred in the 40–49 year age group for non-Hispanic whites, American Indians/Alaska Natives, and non-Hispanic blacks (Figure). Rates among American Indians/Alaska Natives were highest in the 30–39 and 40–49 year age groups and then decreased in the older ages. Rates among non-Hispanic blacks increased dramatically in persons aged 40–49, remained high in persons aged 50–59, and then decreased. Rates were lowest at all ages for Asians/Pacific Islanders.

Discussion

American Indians/Alaska Natives and non-Hispanic whites had the highest drug-induced death rates overall. This finding is consistent with the previous report for rates during 2003–2007 (6). However, it does reflect a change from the 1980s and 1990s, when drug-induced mortality rates were higher among blacks than whites (3). Prescribed drugs have replaced illicit drugs as a leading cause of drug-related overdose deaths (7). Non-Hispanic blacks are less likely than non-Hispanic whites to use prescription drugs, and therefore might be less likely to misuse such drugs (8).

Limitations

The findings in this report are subject to at least two limitations. First, overdose deaths are likely underestimated because lengthy investigations are often required. This sometimes results in a "pending manner and cause of death" category being selected at the close of the mortality file. Second, injury mortality data might underestimate the actual number of deaths for American Indians/Alaska Natives and certain other racial/ethnic populations (e.g., Hispanics) because of the misclassification of race/ethnicity of decedents on death certificates (9).

Conclusion

Preventing drug-induced deaths will require change at many levels (10). Improving prescription drug monitoring programs, which are electronic databases that track prescriptions for opioid pain relievers and other controlled prescription drugs in a state, can assist with identification of improper prescribing and use of these drugs. Health insurers and pharmacy benefit managers can develop prescription claims review programs to identify and address improper prescribing and use of pain relievers. Health-care providers can follow guidelines for responsible prescribing, including screening and monitoring for substance abuse and mental health problems. Patients also should be encouraged to use prescription pain relievers only as directed by a health-care provider, and store and dispose of them properly (http://www.cdc.gov/injury/pdfs/NCIPC_Overview_FactSheet_PPO-a.pdf).

References

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