Emergency Department Visits Involving Nonmedical Use of Selected Prescription Drugs --- United States, 2004--2008

Emergency Department Visits Involving Nonmedical Use of Selected Prescription Drugs --- United States, 2004--2008
Weekly
June 18, 2010 / 59(23);705-709


Rates of overdose deaths involving prescription drugs increased rapidly in the United States during 1999--2006 (1). However, such mortality data do not portray the morbidity associated with prescription drug overdoses. Data from emergency department (ED) visits can represent this morbidity and can be accessed more quickly than mortality data. To better understand recent national trends in drug-related morbidity, CDC and the Substance Abuse and Mental Health Services Administration (SAMHSA) reviewed the most recent 5 years of available data (2004--2008) on ED visits involving the nonmedical use of prescription drugs from SAMHSA's Drug Abuse Warning Network (DAWN). This report describes the results of that review, which showed that the estimated number of ED visits for nonmedical use of opioid analgesics increased 111% during 2004--2008 (from 144,600 to 305,900 visits) and increased 29% during 2007--2008. The highest numbers of ED visits were recorded for oxycodone, hydrocodone, and methadone, all of which showed statistically significant increases during the 5-year period. The estimated number of ED visits involving nonmedical use of benzodiazepines increased 89% during 2004--2008 (from 143,500 to 271,700 visits) and 24% during 2007--2008. These findings indicate substantial, increasing morbidity associated with the nonmedical use of prescription drugs in the United States during 2004--2008, despite recent efforts to control the problem. Stronger measures to reduce the diversion of prescription drugs to nonmedical purposes are warranted.

DAWN is a public health information system that tracks the impact of drug use, misuse, and abuse in the United States by monitoring drug-related hospital ED visits. In a manner similar to the National Electronic Injury Surveillance System,* DAWN uses a sample of EDs to estimate national ED visit rates (2). DAWN collects data from a stratified, simple random sample of approximately 220 nonfederal, short-stay, general hospitals that operate 24-hour EDs in the United States. DAWN's sampling frame is based on the American Hospital Association annual survey database and is updated annually to reflect new, closed, merged, and demerged hospitals, and to give new hospitals an opportunity to be selected into the sample.

The DAWN sample is designed to produce estimates and trends for individual metropolitan areas (12 in 2008) and the United States overall (2). To achieve this, the selected metropolitan areas are oversampled. The oversampled hospitals and a supplementary sample of hospitals outside those areas together capture ED visits in all 50 states and the District of Columbia. Trained DAWN reporters review the medical charts of all patients treated in the participating hospital EDs to identify visits for conditions induced by or related to drug use. DAWN reporters record de-identified information from the ED medical records using standard abstraction forms. DAWN does not conduct interviews or follow-up with clinicians, patients, or family members. Rates presented in this report are based on the numbers of ED visits weighted so that they are representative of the U.S. population. Denominators for this report were based on U.S. Census postcensal estimates. Differences between counts and between rates were tested using two-sided t tests.†

DAWN defines nonmedical use of a prescription or over-the-counter drug as taking a higher-than-recommended dose, taking a drug prescribed for another person, drug-facilitated assault, or documented misuse or abuse, all of which must be documented in the medical record. DAWN classifies suicide attempts, patients seeking detoxification, and unintentional ingestions in other categories.

For 2008, a total of 231 hospitals submitted data that were used for estimation. The overall weighted hospital response rate was 32.9% (response rates have been stable from year to year). In 2008, DAWN recorded 351,697 drug-related ED visits. On average, a DAWN member hospital submitted 1,522 DAWN cases.

DAWN estimated 1.6 million ED visits for the misuse and abuse of all drugs in 2004 and 2.0 million in 2008. Among these, illicit drugs such as cocaine and heroin were involved in 1.0 million visits in both 2004 and 2008, whereas prescription or over-the-counter drugs used nonmedically were involved in 0.5 million visits in 2004 and 1.0 million visits in 2008. The estimated number of ED visits involving nonmedical use of opioid analgesics§ increased from 144,600 in 2004 to 305,900 in 2008 (111%, p<0.001), whereas rates increased from 49.4 per 100,000 to 100.6 per 100,000, an increase of 104% (p<0.05).

ED visit rates for opioid analgesics were highest for oxycodone, hydrocodone, and methadone during the entire study period (Figure 1). Estimated ED visits involving oxycodone increased from 41,700 to 105,200 (p<0.001), and rates increased from 14.2 per 100,000 to 34.6 per 100,000, an increase of 144% (p<0.05). The estimated number of ED visits involving nonmedical use of benzodiazepines increased from 143,500 in 2004 to 271,700 in 2008 (89%, p=0.01), and rates increased from 49.0 to 89.4 per 100,000, an increase of 82% (p<0.05). The increases in numbers of ED visits during 2004--2008 for individual benzodiazepines were significant: alprazolam (125%, p=0.01), clonazepam (72%, p<0.001), diazepam (70%, p=0.02), and lorazepam (107%, p=0.006), as was the increase for the sleep aid zolpidem (121%, p=0.002). Carisoprodol-related visits also increased significantly (132%, p=0.04). The estimated number of visits for alprazolam in 2008 (104,800) was more than twice the number for the next most common benzodiazepine, clonazepam (48,400).

Although women had more benzodiazepine-related visits than men (Table), this difference was not statistically significant. Among opioid analgesic--related visits, 38% did not involve any other drug (including alcohol); the corresponding figure was 21% for benzodiazepine-related visits. Benzodiazepines were involved in 26% of opioid analgesic--related visits. Alcohol was involved in 15% and 25% of visits for opioids and benzodiazepines, respectively. Approximately one in four patients was admitted. For the year 2008, rates for both types of drugs increased sharply after age 17 years, peaked in the 21--24 years age group, and declined after age 54 years (Figure 2). The largest increases during 2004--2008 occurred among persons aged 21--29 years.

Reported by
R Cai, MS, E Crane, PhD, K Poneleit, MPH, Office of Applied Studies, Substance Abuse and Mental Health Services Admin. L Paulozzi, MD, Div of Unintentional Injury Prevention, National Center for Injury Prevention and Control, CDC.

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Emergency Department Visits Involving Nonmedical Use of Selected Prescription Drugs --- United States, 2004--2008