For methodological information for a particular year or date range, please check the codebook for a specific data set from the sidebar to the right.
Sample
The legacy version of DAWN employs a multistage sampling design for the selection of EDs for analysis. Stratified simple random sampling with oversampling in selected metropolitan areas is used to select the hospitals.
DAWN's target sample frame consists of all nonfederal, short-stay, general medical and surgical hospitals in the United States that have one or more EDs open 24 hours a day.
DAWN cases are identified by the systematic, retrospective review of ED medical records in participating hospitals. Due to the volume of cases in some EDs, a sample of medical records may be selected for review.
Weight
The legacy version of DAWN includes a set of complex sample design variables to calculate estimates for the universe of DAWN-eligible hospitals in the United States from the sampled hospitals participating in DAWN.
The primary sampling weights reflect the probability of selection, and separate adjustment factors are included to account for sampling of ED visits, nonresponse, data quality, and the known total of ED visits delivered by the universe of eligible hospitals.
DAWN design variables include variance estimation stratum (STRATA), PSU, replicate (REPLICATE), PSU frame count (PSUFRAME), and case weight (CASEWGT).