How estimates are calculated

WaitWise turns anonymous, community-submitted wait-time reports into a single estimate and a confidence level for each emergency department. This page explains that process in plain language.

Only recent reports count

Every report has an expiry window (shown on each hospital’s page, typically a few hours). Once a report passes that point, it is automatically dropped from the public estimate — old information is never silently kept around and presented as current.

Recent reports count more

Among the reports still within the expiry window, more recent ones are weighted more heavily than older ones. A report from ten minutes ago has more influence on the estimate than one from two hours ago.

A typical value, not an average

Rather than averaging every report — which a single extreme value could distort — WaitWise trims the highest and lowest reports and then finds the weighted midpoint (median) of what remains. This keeps one unusually short or long report from swinging the estimate.

One device, one vote

If the same device reports for the same emergency department more than once in the current window, only its most recent report counts toward the estimate. This keeps a single person from dominating the result.

Confidence levels

The confidence label reflects three things: how many recent reports there are, how recent they are, and how closely they agree with each other.

• High confidence — several recent reports that agree closely.
• Medium confidence — a moderate number of reports, or somewhat wider disagreement.
• Low confidence — very few reports, or reports that disagree widely.
• Insufficient data — no recent reports at all. WaitWise shows this plainly rather than guessing.

Quality and moderation

Reports go through automated checks for plausibility and unusual patterns before they count toward an estimate, and community members can flag a report they believe is wrong. Reports that are removed or still under review are excluded from the public estimate. We don’t publish the exact detection rules, since doing so would make them easier to game — but the checks never use anything beyond what you submit in the report form.

This is not official data

These estimates come entirely from anonymous community reports. They are not provided by, verified by, or affiliated with any hospital or health authority, and should never be used to decide whether or when to seek emergency care.