Drug Abuse Warning Network (DAWN), 2006 (ICPSR 33221)

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

   Information on drug-related ED visits is based on a sample and is, therefore, subject to sampling variability. Hospital participation rates in oversampled metropolitan areas typically have been 50 percent or higher. However, the participation rate in the remainder of the United States has been lower, in the range of 20 to 30 percent, since the DAWN redesign in 2003. In any sample survey, a low response rate is of concern because it creates the opportunity for bias. That is, nonparticipating hospitals may have different characteristics than participating hospitals, possibly including differences in the drugs reported, types of drug-related ED visits, patient disposition, or population demographics.

   Although every effort is made during the data collection phase to collect data accurately and precisely, extant medical records vary in specificity and detail. Therefore, factors that may affect the reliability and accuracy of the findings include the following:

   • DAWN data collectors attempt to identify with a high degree of specificity the exact drugs involved in an ED visit. If extant medical records include only a general description of a drug (e.g., "benzodiazepines" or "opiates"), the drug is grouped in a general category (e.g., "benzodiazepines not otherwise specified"). Similarly, records often describe a drug as amphetamines without specifying if it is methamphetamine.

   • DAWN seeks to report only drugs that are related to the ED visit, not all the drugs or medications that the patient may be taking on a regular basis as prescribed by a doctor. If the ED record is not clear on this point, drugs may be included in the data that are not specifically related to the visit. For example, anecdotal evidence suggests that methadone may be over-reported when the medical records fail to mention that the patient is in a methadone treatment program. The opposite is also true; a current medication may be involved in the ED visit but not recognized as a contributing factor by the clinician.

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 multi-level 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. Office of Applied Studies. Drug Abuse Warning Network (DAWN), 2006. ICPSR33221-v3. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2015-11-23. http://doi.org/10.3886/ICPSR33221.v3

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

2015-01-19 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).

2013-08-12 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.

2012-06-12 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.