A stepped-wedge trial of 1,775 heart attack patients in high-risk Australian communities found that a multicomponent education program actually *reduced* emergency medical service (EMS) use by 9 percentage points, challenging assumptions that teaching people to recognize heart attack symptoms translates to better emergency response.
Researchers in Victoria, Australia, tested whether community education about acute coronary syndrome (ACS) symptoms could improve how quickly people call EMS and seek emergency care in eight high-risk areas (four metropolitan, four rural) with historically low EMS utilization. The intervention, called Heart Matters, was ambitious in scope: 490 community sessions reaching approximately 10,000 residents directly, 174,000 household mailouts, 50,000 resource handouts, media campaigns, and geotargeted social media reaching roughly 350,000 people across a population of 792,000.
The unexpected finding: the intervention was associated with a *decrease* in EMS use. During the control period (no education campaign), 68.6% of ACS patients arrived at hospitals by ambulance. After the education program rolled out, this dropped to 63.4% - an adjusted difference of 9 percentage points lower in the intervention group. While early treatment-seeking (calling 911 quickly) was also lower in the intervention period, the estimates were imprecise. The effect was more pronounced in metropolitan areas (10.7 percentage point reduction) and notably larger during a severe flooding event (13.5 percentage point reduction).
The context matters considerably. The trial ran from December 2021 to March 2023 with follow-up through March 2024. During the initial control period, a COVID-19 wave coincided with unexpectedly high baseline EMS use (68.6%), which the researchers note was already higher than what the study was designed to detect improvement from. The program evaluation revealed that community concerns about EMS costs, wait times, and system demands may have created barriers independent of symptom knowledge. External shocks, including the pandemic and natural disasters, appeared to significantly influence patient behavior in ways that community education alone could not overcome.
This is a methodologically rigorous trial: 1,775 patients (865 in intervention, 910 in control), mixed-effects regression analysis, stepped-wedge cluster randomization across eight geographically distinct communities. The finding is sobering because it suggests that the gap between knowing heart attack symptoms and actually calling for emergency care is not simply a knowledge problem. Even comprehensive, multimodal education reaching hundreds of thousands of people did not shift behavior in the intended direction.
Recognize the limits of education alone. If you or someone you know experiences chest pain, pressure, shortness of breath, or other classic ACS symptoms, calling emergency services remains the correct action regardless of awareness campaigns. Knowledge about symptoms matters, but this study suggests external factors - cost concerns, system strain, trust in EMS, concurrent crises - shape real-world behavior more than messaging alone.
System barriers matter as much as awareness. The study's program evaluation flagged community concerns about EMS costs and wait times as meaningful obstacles. If these barriers are present in your area, that's a structural problem education cannot fix. Advocating for accessible emergency services in your community may be more impactful than additional awareness campaigns.
Context shapes outcomes unpredictably. A pandemic wave and flooding event modified how education translated into behavior. During crises or periods of system stress, your decision to seek emergency care depends on your perception of system capacity, your economic ability to use it, and situational factors beyond personal knowledge.
| Parameter | Details |
|---|---|
| Study type | Stepped-wedge cluster-randomized controlled trial |
| Sample size | 1,775 ACS patients (865 intervention, 910 control) |
| Population | Adults in 8 Victorian communities (792,000 residents); 52% aged 65+; 67% male |
| Intervention | Heart Matters multicomponent program: 490 community sessions, 174,000 household mailouts, 50,000 resource handouts, media and social media campaigns reaching ~350,000 |
| Control | No educational campaign |
| Primary outcome | Proportion of ACS patients transported by EMS |
| Key finding | EMS transport decreased in intervention group (63.4% vs 68.6% control); adjusted RD -8.98% (95% CI -17.50 to -0.46%, P=0.04) |
| Secondary findings | Early treatment-seeking lower in intervention period (imprecise estimates); effects more pronounced in metropolitan areas and during flooding |
| Time period | December 2021 to March 2023 (intervention), follow-up to March 2024 |
| Confounders | COVID-19 pandemic wave during control period; natural disasters; community concerns about EMS costs and wait times |
| Analysis | Mixed-effects regression models with risk differences and odds ratios |
Chew DP, et al. Heart Attack Education and EMS Response in High-Risk, Low EMS Usage Areas: A Stepped-Wedge Cluster-Randomized Trial. JAMA Netw Open. 2025. PubMed: 42043820
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