Source data
The register is built from the CMS Timely and Effective Care - Hospital dataset, refreshed quarterly. It covers every Medicare-participating U.S. hospital that reports ED throughput measures — 4660 hospitals at last refresh.
What v1 surfaces
- OP-18b — median time (minutes) from ED arrival to discharge for discharged patients. The canonical ED-throughput measure. National median 148 minutes
- OP-18c — same measure restricted to psychiatric / mental health patients (often dramatically higher due to capacity-of-care issues for behavioral health)
- OP-22 — left-before-being-seen rate. The direct patient signal of ED overcrowding
- EDV — CMS volume bucket (very low / low / medium / high / very high)
- SEP-1 — severe sepsis & septic shock 3- and 6-hour bundle compliance. ED throughput is the upstream gate
- STK-02 / 03 / 05 — stroke care timeliness measures, also throughput-dependent
- SAFE_USE_OF_OPIOIDS — concurrent prescribing safety, an acute-care risk-management measure
Branmoor's signal aggregation
For each hospital we compute a per-measure comparison against the national P25 / median / P75 distribution and aggregate into a single signal flag:
- Elevated ED-throughput stress — 3 or more measures in the worst quartile (above P75 for lower-is-better measures, below P25 for higher-is-better), or composite capacity-stress score > 0.5
- Mixed signal — 1+ measure in the worst quartile
- Strong ED throughput — 2 or more measures in the best quartile and none in the worst
- Neutral — otherwise
The composite capacity-stress score combines OP-18b (arrival-to-discharge time) and OP-22 (left-before-seen rate) into a single number that approximates relative ED overcrowding. Methodology: each measure's relative deviation from the national median is summed.
What v1 is not
v1 surfaces the CMS-published acute-care substrate. It is not the real-time capacity surveillance product the full ED Boarding & Ambulance Diversion Surveillance scope (per the original spec) delivers. v1 does not include:
- State EMS diversion data — some states require ambulance diversion reporting (varies wildly by state). Per-state ingest. Effort: XL
- EMTALA transfer patterns from claims — Medicare and Medicaid claims expose the transfer signal at the regional level. DUA-gated for full claims
- FAA flight data + helipad mapping — flight data is clean public; tail-number-to-helipad mapping is manual curation but finite work
- Real-time hospital staffing signal — CMS staffing data is lagged. Real-time requires partnerships or scraping hospital workforce dashboards (where public)
See the product page for the paid v2 layer and the EMS-agency / payer / health-system sales motion.
Update cadence
CMS refreshes the Timely and Effective Care dataset quarterly. Branmoor re-ingests on each site deploy.
Limits
ED throughput measures lag 6–12 months from the measurement period. The register reflects sustained operating patterns, not real-time capacity. For real-time signal, the paid layer is the right channel.
Hospitals below CMS minimum-volume thresholds for a measure are flagged as Not Available rather than scored.