Maryland | Colorado | Massachusetts | |
---|---|---|---|
Large academic hospital | All acute care hospitals in the state | All acute care hospitals in the state | |
Number of hospital EDs in the study (in the sampling frame) | 1 | 80a | 71 |
Number of records in random sample | 234 | 260 | 400 |
% of state population covered by hospital(s) (catchment area) | 15% | 100% | 100% |
Dates of the ED visits in the billing data set | Jan 2018–Dec 2019 | Jan 2019–Dec 2019 | Oct 2017–Sep 2018 |
Number of diagnosis fields in the ED billing data set | 32 | 30 + 3 cause fields | 30 + 1 cause field |
Medical record reviewer | 10 clinical researchers | 1 professional coder | 3 professional coders |
Data source | Electronic medical record | ED report and EMS transportb | Full ER recordc |