Uninsured STEMI Patients More Likely to Be Transferred, But What Does It Mean?
Patients with STEMI who lack health insurance are more likely to be transferred to another center than are their insured counterparts, a database study shows. But without information on which centers did or did not have PCI capability at the time patients presented, a definitive explanation for the observation remains elusive.
It likely comes down to an access issue, in which uninsured patients are disproportionately seeking care at centers that are not equipped to perform PCI and thus require transfer, not that centers are looking to unload patients who don’t have coverage, lead author Michael Ward, MD (Vanderbilt University, Nashville, TN), told TCTMD.
Ward noted that 61% of US hospitals are not set up to perform PCI and said it remains unclear whether patients without insurance are more likely to go to these centers than are insured patients. The database used in the current study did not have information on which centers could perform PCI, although Ward said he and his colleagues attempted to account for that by adjusting for overall rates of transfer at each center. Even after doing so, uninsured patients were more likely to be sent to another facility.
Commenting on the study for TCTMD, Tim Henry, MD (Cedars-Sinai Medical Center, Los Angeles, CA), said the inability to identify PCI and non-PCI centers is a “huge limitation” and guessed that nearly all of the transfers identified in the study were from a center without PCI capabilities to a PCI center.
“I think that this is the only likely explanation, because the transfer from a PCI center to another PCI center is exceedingly rare,” he said.
Henry said the relationship seen in the study, then, is probably driven by the large numbers of uninsured people—farmers in particular—living in rural areas that often have smaller hospitals that are not equipped to perform PCI.
And that comes back to the access issue raised by Ward, who said, “The point is that those who don’t have insurance are less likely to get the timely care that they need.”
Although the current study—which was published online ahead of print in the American Journal of Cardiology—did not include information on clinical outcomes, Ward and his colleagues note that the link between timeliness of myocardial reperfusion, especially when patients require transfer, and clinical outcomes has been well established.
Transfer Rates Increasing Over Time
The investigators looked at data from the Nationwide Emergency Department Sample on 1,377,827 STEMI visits between 2006 and 2011 that resulted in either an interfacility transfer or hospitalization at the initial center. Most patients were covered by Medicare (59%), 34.2% had private insurance, 6.8% were enrolled in Medicaid, and 8.0% were uninsured.
Overall, 18.1% of patients were transferred to another facility, with a higher rate among those who were uninsured (26.8% vs 17.3%). After adjustment, patients without health insurance were 60% more likely to be transferred than were those with any type of insurance (OR 1.6; 95% CI 1.5-1.7). The finding was consistent when lack of insurance was compared with any of the three categories of insurance.
The transfer rate increased over time, from 14.9% in 2006 to 20.1% in 2011. Uninsured patients were more likely to be sent to another facility for each year of the study period.
That rise occurred at a time when the overall number of STEMIs was declining, Ward noted. “That emphasizes the importance of this whole transfer process, especially as we get to more of a hub-and-spoke-type model where you have these outlying facilities and [patients] get sent to the facilities that have specific capabilities,” he said.
Henry interpreted the increasing rate of interfacility transfers, as well as the greater likelihood of transfer among uninsured patients, as positive.
“My concern would have been that patients without insurance would have been transferred less because the PCI center wouldn’t accept them. . . . This shows me that care in America is good,” Henry said.
But still, Ward said, the findings reveal areas for improvement for uninsured patients. “Yes, it’s a good thing that they’re able to be transferred,” he said, “but it still points to critical access issues for this population.”
More Information Needed
Although access issues appear to be at the center of the observed relationship, a fuller understanding of the reasons remains an important area for future research, Ward said.
Commenting on the study for TCTMD, Tracy Wang, MD (Duke Clinical Research Institute, Durham, NC), pointed out information that would improve interpretation of the results.
Administrative data of the type used in this study lack details about the acuity of presentation, and it could be that uninsured patients are more viable candidates for transfer, she told TCTMD in an email. It could also be that uninsured patients are more likely to delay seeking care and thus may require a higher intensity of care by the time they arrive in the emergency department, she said.
Numerous other questions could not be answered with the available data, Wang said, including whether there are differences in how uninsured patients are treated across centers, whether the uninsured are more likely to present to centers without 24/7 PCI capabilities, when the decision to transfer was made, what the door-in-door-out time was, and how many patients received fibrinolytics before transfer.
“In my opinion, transfer in and of itself may be too coarse an outcome to assess for disparities in care,” she said. “To be sure, transfers delay reperfusion, but for many patients, transfer may be better than no transfer or no reperfusion at all.”
As for the idea that uninsured patients are transferred simply because they lack coverage, Wang said, “I find the message that uninsured patients may be selectively designated for transfer a bit hard to stomach. Insurance status is just not a question that comes up during cath lab activation calls.”
- Ward MJ, Kripalani S, Zhu Y, et al. Role of health insurance status in inter-facility transfers of patients with ST-elevation myocardial infarction. Am J Cardiol. 2016;Epub ahead of print.
- Ward reports receiving support from the National Heart, Lung, and Blood Institute.
- Interhospital Transfer Improves Outcomes for Acute MI Patients
- In STEMI Transfer, Less Time at Referral Hospital Means Better Outcome
- STEMI Patients Not Achieving Recommended Transfer Times for PCI