We check ourselves. Our wait forecasts land within 20 minutes of what the hospital actually posted next 45% of the time, about 18% sharper than assuming the wait won't change, measured against 349,441 real hospital updates over the last 53 days. We only publish this figure once there's enough history to stand behind it.
Every few minutes we record what each ER posts. Later we compare what we forecast for a given moment against what the hospital actually posted then, and against a naive “no change” guess. That backtest is exactly what the figure above reports; nothing is hand-tuned, and it covers every tracked ER at once.
Canada has no common definition of an ER wait time. Of the 717 emergency departments we track, 211 publish something live, but Quebec posts stretcher occupancy, New Brunswick posts length of stay, and others post an estimate of the wait to be seen. We keep each in its own units and never blend them into a fake single number. See the national picture →
The clock starts at triage or registration. “Time to be seen” ends at the first physician assessment (this is the live posted wait, and CIHI's measure of it). For patients who are admitted, “total time in the ER” keeps running until a hospital bed frees up and they leave the emergency department, which is why it can be long. Most patients are treated and discharged before that point, so they spend less time in the ER.
Our live numbers are estimates; CIHI, Canada's national health-data agency, publishes what was actually measured. In 2024-2025, across the provinces it reports, 90% of emergency patients were seen by a physician within 3.2–8.9 hours, and 9 in 10 admitted patients spent up to 29–107 hours in the ER before moving to an inpatient bed (their time in the emergency department, not the hospital stay). Each hospital page shows its own official figure beside what it posts live, the estimate for right now, the official benchmark for the year.
Across 43 hospitals where we track a live wait and CIHI publishes an official measure, the two move together: the ERs that post longer waits are generally the ones CIHI measured as slower (correlation 0.77, where 1.00 would be a perfect line-up). A posted wait is a real-time estimate and CIHI's figure is the annual 90th percentile, so this shows the two agree in direction, not a hospital-by-hospital accuracy score.
We read first-party hospital feeds directly and stamp every reading with the time the hospital said it was current. If a feed goes stale or freezes on one value, we flag it instead of showing an old number as if it were live, and each hospital page carries a “How reliable is this number?” note for its own feed.