Beyond the Stopwatch: What Denver’s EMS Response-Time Story Should Really Make Us Ask

The recent CBS Colorado report regarding Denver Health ambulance response times deserves attention, but perhaps for reasons that go beyond the response-time delays highlighted in the story. The report cites cases in which a Denver Health ambulance crew arrived later than the nine-minute goal.

Denver's experience raises a broader question: Should every EMS call be judged by the same clock?

Denver Health's core 9-1-1 ambulance operation doesn’t appear to receive a direct municipal operating subsidy, making the prospect of simply adding ambulance resources, and the substantial cost associated with them, particularly relevant.

This conversation is especially timely. In September, the Academy of International Mobile Healthcare Integration (AIMHI) hosted a webinar, Beyond Response Times: Redefining What Great EMS Looks Like, examining how high-performance EMS systems are moving beyond the stopwatch as their primary measure of success.

The 2026 AIMHI benchmarking data found that only 37.3% of responses received a lights-and-siren response, reflecting an increasingly patient-centered philosophy: get the right resource to the right patient at the right time, rather than getting every resource everywhere as fast as possible. Just as importantly, these systems increasingly measure what happens after the ambulance arrives; clinical outcomes, patient experience, safety, efficiency, financial sustainability and value.

Response time tells us what EMS did. It does not necessarily tell us what EMS accomplished.

Denver Health Excels in the Metrics That Matter

For decades, EMS has relied heavily on response time because it’s easy to measure, easy to explain, and easy to put into a contract. But easy to measure doesn't necessarily mean clinically meaningful.

It’s important not to let the response time discussion obscure areas where Denver Health demonstrates strong clinical performance. Its published measures show a system focused on time-sensitive patient care: in 2025, median scene time for critical blunt trauma was 8:07 against a 9:00 goal, while penetrating-trauma scene time was 5:27 against a 6:00 goal. Denver Health has also historically reported cardiac-arrest survival and continues to track clinically meaningful processes such as early 12-lead ECG acquisition and rapid STEMI notification. These measures get closer to what patients actually need from an EMS system, not simply an ambulance arriving quickly, but clinicians rapidly recognizing life threats, delivering appropriate treatment and moving patients toward definitive care. Response time matters, but clinical performance helps tell us whether the response actually mattered.

This Isn't Just an Ambulance Issue

Denver uses a tiered EMS response system. Denver Fire provides BLS first response, while Denver Health provides ALS and ambulance transportation. Both have response-time goals, and both have struggled to meet them. Denver Fire’s goal is to arrive within five minutes of unit assignment on 90% of responses.

Denver’s independent auditor examined more than 71,000 Denver Fire EMS incidents and nearly 65,000 Denver Health incidents from May 2023 through March 2024. Denver Fire achieved its five-minute goal on only 74% of responses, with a 90th-percentile response of 6:11.

When the auditor examined the entire response interval, including 9-1-1 processing, Denver Fire met its 6:30 objective on only 49% of incidents, while Denver Health met its 10:30 objective approximately 70% of the time.

Modernize the System Using Evidence-Based Research and Local Data

Denver Health reports that its dispatchers are certified in Emergency Medical Dispatch (EMD), using that process to help determine what EMS resources should be sent to individual calls.

That's important because EMD exists precisely because not every 911 medical call carries the same clinical urgency.

A patient in cardiac arrest, severe respiratory distress, shock or major hemorrhage clearly requires a rapid response. Minutes, and sometimes seconds, matter.

But does a stable patient with a minor injury or low-acuity illness derive the same clinical benefit from an ambulance arriving in nine minutes instead of 15 or 20?

Does that same patient need a fire company within five minutes?

Those aren't arguments for ignoring response time. They're arguments for making response time clinically meaningful. The goal isn't to make low-acuity patients wait longer; it's to make sure high-acuity patients don't wait because resources were unnecessarily committed elsewhere.

An EMS Resource Can Only be in One Place at a Time

A prolonged ambulance response to a patient who isn’t breathing is fundamentally different from a prolonged response to a stable patient with a low-acuity complaint.

That’s exactly why treating the two responses as equivalent can be problematic.

Instead of asking only, “What percentage of ambulances arrived within nine minutes?”, perhaps we should also ask: “For patients whose conditions were truly time-sensitive, how reliably did we get the right resources there quickly?”

Dispatch shouldn’t simply determine how fast we drive to a call. It should help determine what we send, how quickly we need to get it there and, in appropriate circumstances, whether that resource needs to be sent at all.

Denver's experience suggests this isn't simply an ambulance-response problem. It's a system-design question.

Perhaps success shouldn't mean getting every fire company there within five minutes and every ambulance there within nine. Perhaps success means getting the right resource to the right patient within the amount of time that patient's condition actually requires.

And if we're going to stop judging EMS primarily by how fast it arrives, we'd better start measuring what happens after it gets there.