Drug Abuse Warning Network (DAWN), 2009 (ICPSR 31921)

1. Several limitations to the data exist and should be noted prior to using this DAWN file:

   • DAWN data collectors attempt to identify with a high degree of specificity the exact drugs involved in an ED visit, but extant medical records vary in specificity and detail. If extant medical records include only a general description of a drug (e.g., "benzodiazepines"), the drug is grouped in a general category (e.g., "benzodiazepines not otherwise specified").

   • Many drug-related ED visits involve multiple drugs. In these instances, it may be difficult or impossible to determine whether a single drug is responsible for the visit or if the visit was the result of the interaction between the drugs.

   • When multiple drugs are involved, it should not be assumed that they are all taken for the same reason; a patient may misuse one type of prescription medication while taking another medication as prescribed.

   • While DAWN seeks to report only the drugs that are related to the ED visit, some unrelated drugs may be included if ED records fail to indicate that they were obtained through a legitimate prescription, were taken as prescribed or indicated, and were unrelated to the ED visit. For example, anecdotal evidence suggests that ED records may mention methadone but fail to indicate that the patient was enrolled in a methadone treatment program and that the methadone was unrelated to the medical emergency leading to the ED visit.

   • DAWN does not produce rates (visits per 100,000 population) for race/ethnicity groups. Information on race and ethnicity is often poorly documented in extant ED records. In addition, some hospitals consider race/ethnicity to be private information and will not make it available to DAWN Reporters. About 15 percent of visits each year do not contain race/ethnicity information. These missing data result in the systematic understatement of visits by race/ethnicity category.

   • Although DAWN documents whether a drug was positively confirmed by toxicology testing, DAWN does not require that drugs reported for the ED visit be confirmed by laboratory testing. Toxicology tests are not used consistently across EDs, and some toxicology tests are not specific enough to identify particular drugs. Furthermore, a positive toxicology test is not necessarily evidence of recent drug involvement in an ED visit if it is a current medication or a drug that persists in the system long after it was used. For this reason, DAWN requires that the involvement of drugs be mentioned in the ED record, not just in the toxicology testing results, for the visit to be considered a DAWN case.

   • Information on drug-related visits is based on a sample and is therefore subject to sampling variability. Standard error measurements are provided in many tables to reflect the sampling variability that occurs (a) by chance because only a sample rather than the entire universe is surveyed, and (b) due to nonresponse.

   • As in any survey, a low response rate is of concern because it creates larger-than-expected sampling errors plus the opportunity for unpredictable biases. DAWN addresses these issues for the short term by always reporting standard errors based on the actual sample of respondents, and for the long term by continuing its efforts to raise the hospital participation rate.

2. Major changes to DAWN were instituted during 2003 as the result of a redesign intended to improve the quality and representativeness of DAWN estimates. Changes included the design of the hospital sample, a new case definition for drug-related ED visits eligible for DAWN, revised data items submitted on these cases, a new protocol for case finding, and improved quality assurance measures. These improvements created a permanent disruption in trends. As a result, comparisons cannot be made between the old DAWN (2002 and prior years) and the redesigned DAWN (2004 and forward). The year 2003 was a period of transition between the old DAWN and the redesigned DAWN. As a result, only interim, half-year estimates were produced for 2003.

3. Several measures have been taken to protect the confidentiality of DAWN data:

   • In the public use file, complex design variables have been adjusted to optimize disclosure protection while preserving the original design and statistical properties of the data to the highest degree possible. Specifically, each year primary sampling units (PSUs) are randomly selected for combination or division and original strata may be combined with adjacent strata. Self-representing PSUs may be treated as non self-representing as a result of this process. Case weight, replicate, and PSU frame count values are adjusted to reflect changes to PSUs and strata and to further maximize disclosure protection.

   • PSU and strata identification values are randomized each year. While DAWN is not designed to identify the contribution or influence of a particular hospital, applied disclosure protection methods and identification value randomization preclude multilevel modeling at the hospital-level and comparison of individual sampling units over time.

   • While disclosure protection has been applied to minimize deviance from the original sampling error calculation model, statistical analyses generated from the public use file may vary from results provided on the DAWN Web site. For online analysis using Survey Documentation and Analysis (SDA), complex design variables are used to generate statistical results, but are not directly accessible. Therefore, SDA utilizes original design variables modified slightly to accommodate the variance estimation capabilities of the SDA statistical program.

4. Original variables recoded for disclosure protection include:

   • Quarter: Month of episode has been recoded into quarter.

   • Day part: Exact time of episode has been recoded into four day part categories.

   • Case disposition: "Chemical dependency/detox" has been combined with "Psychiatric unit". Hospitals with combined chemical dependency and psychiatric units are included in the "Other inpatient unit" disposition category.

• United States Department of Health and Human Services. Substance Abuse and Mental Health Services Administration. Center for Behavioral Health Statistics and Quality. Drug Abuse Warning Network (DAWN), 2009. ICPSR31921-v4. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2015-11-23. http://doi.org/10.3886/ICPSR31921.v4

2015-11-23 Covers for the PDF documentation were revised.

2015-01-20 For a small number of cases (approximately 1%), some of the drug mention variables (i.e. CATID_1_1 and TOXTEST_1) were updated to reflect the current drug categorizations from the Drug Reference Vocabulary (DRV).

2013-08-09 The latest update provides uniform drug codes and labels across all years of the series. The update also includes the addition of energy drinks to the drug category (DRUGID) variables.

2012-01-24 A few minor edits were made to the hyperlinks found in the front section of the codebook.

2011-12-20 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

• Performed consistency checks.
• Created variable labels and/or value labels.
• Standardized missing values.
• Created online analysis version with question text.
• Performed recodes and/or calculated derived variables.
• Checked for undocumented or out-of-range codes.