Trends and geographic patterns in drug-poisoning death rates in the U.S., 1999-2009.
BACKGROUND
Drug poisoning mortality has increased substantially in the U.S. over the past 3 decades. Previous studies have described state-level variation and urban-rural differences in drug-poisoning deaths, but variation at the county level has largely not been explored in part because crude county-level death rates are often highly unstable.


OBJECTIVE
The goal of the study was to use small-area estimation techniques to produce stable county-level estimates of age-adjusted death rates (AADR) associated with drug poisoning for the U.S., 1999-2009, in order to examine geographic and temporal variation.


METHODS
Population-based observational study using data on 304,087 drug-poisoning deaths in the U.S. from the 1999-2009 National Vital Statistics Multiple Cause of Death Files (analyzed in 2012). Because of the zero-inflated and right-skewed distribution of drug-poisoning death rates, a two-stage modeling procedure was used in which the first stage modeled the probability of observing a death for a given county and year, and the second stage modeled the log-transformed drug-poisoning death rate given that a death occurred. Empirical Bayes estimates of county-level drug-poisoning death rates were mapped to explore temporal and geographic variation.


RESULTS
Only 3% of counties had drug-poisoning AADRs greater than ten per 100,000 per year in 1999-2000, compared to 54% in 2008-2009. Drug-poisoning AADRs grew by 394% in rural areas compared to 279% for large central metropolitan counties, but the highest drug-poisoning AADRs were observed in central metropolitan areas from 1999 to 2009.


CONCLUSIONS
There was substantial geographic variation in drug-poisoning mortality across the U.S.
Office of Analysis and Epidemiology, National Center for Health Statistics, CDC, Hyattsville, Maryland. Electronic address: lrossen@cdc.gov.
Lauren M
LM
Rossen
Diba
D
Khan
Margaret
M
Warner
D017677:Age Distribution; D001499:Bayes Theorem; D002423:Cause of Death; D062787:Drug Overdose / Q000453:epidemiology / Q000401:mortality*; D006801:Humans; D015233:Models, Statistical; D011041:Poisoning / Q000453:epidemiology / Q000401:mortality*; D011159:Population Surveillance; D011336:Probability; D012424:Rural Population; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014505:Urban Population