Chapel Hill, NC - A new study has found that those with Medicaid insurance and those living in low-income neighborhoods are less likely to get to the hospital within two hours of an acute MI, compared with those from higher-income areas or with better insurance [1]. Randi E Foraker (University of North Carolina, Chapel Hill, NC) and colleagues report their findings in the September 22, 2008 issue of the Archives of Internal Medicine.

As outcomes following AMI are generally more favorable if prehospital delay time is minimized, "it is imperative that we find out what is lacking in these neighborhoods that prohibits people from seeking care," Foraker told heartwire.

The results suggest a need for increased recognition of and rapid response to AMI symptoms within these populations, "so everyone is aware of when and how quickly they should get to the hospital upon MI-symptom onset. People need to understand the implications: if you delay too long in getting to the hospital you may not be eligible for time-dependent MI treatment," she says.

Foraker and colleagues explain that previous research has shown an association between prolonged prehospital delay time following acute MI and female sex, black race, advanced age, hypertension, and diabetes, but there is a paucity of data regarding delay for MI and socioeconomic status.

And despite efforts to reduce the time between the onset of AMI symptoms and hospital arrival, prehospital delay times "have not improved over the years," they note.

So they examined the association of neighborhood household income and health-insurance status with time elapsed between the onset of symptoms and arrival at the hospital among 6746 men and women with a validated, definite, or probable AMI in the Atherosclerosis Risk in Community Surveillance Study (ARIC).

Participants' addresses were geocoded and linked with US census data, with household income for each participant's area classified as low (<$33,533 per annum), medium ($33 533-$50 031), or high (>$50 032). Health-insurance status was noted and the distance from the residence to the hospital was calculated.

Of the patients, 36% arrived at the hospital within two hours of developing symptoms (short delay), 42% between two and 12 hours (medium delay) and 22% between 12 and 72 hours (long delay).

Low neighborhood household income was independently associated with higher odds of long vs short delay (odds ratio 1.46) and medium vs short delay (OR 1.43) compared with high-income neighborhoods in a model including age, sex, race, and study community.

"These associations persisted after additionally controlling for health-insurance status, diabetes, hypertension, emergency medical services (EMS) use, chest pain, year of AMI event, and distance from residence to hospital," the authors explain.

And patients with Medicaid were more likely to have a long vs short delay (OR 1.87) and a medium vs short delay (OR 1.76) compared with those with prepaid insurance or prepaid plus Medicare.

"We found that those from lower-socioeconomic neighborhoods tended to delay longer than patients from higher-socioeconomic neighborhoods, and also those with Medicaid coverage delayed longer compared with either prepaid insurance or prepaid plus Medicare," Foraker told heartwire.

"Reducing socioeconomic and insurance disparities in prehospital delay is critical because excess delay time may hinder effective care for acute myocardial infarction.

"Of course, we are not able to discern from these data the reasons behind the findings," she added. "But we have some hypotheses about how the infrastructure and the resources available to these communities might play a role. For example, perhaps EMS are not routed efficiently through lower-income neighborhoods."

Interventions that are being considered include the following: community education and awareness campaigns, targeted interventions by healthcare professionals aimed at reducing prehospital delay among patients with known coronary heart disease, and promoting EMS use throughout the community.