Changing acute MI outcomes by health insurance type: A window into insurer influence

Older Americans with acute MI enrolled in Medicare Advantage (MA) plans in 2009 had similar or slightly better short-term mortality compared to those on traditional health insurance, with evidence of lower utilization resources while in hospital and after discharge, according to an analysis of US data. By 2018, the survival gap had narrowed, but some differences remained.

Changes over time in the two managed plans offer a chance to better understand the influence of type of insurance in the United States, the researchers say.

“Over the past 10 years or more, there has been tremendous growth in Medicare Advantage enrollment to the point where, in the current year, just over 50% of those eligible to enroll in Medicare Advantage enroll in MA plans,” Bruce E. Landon, MD (Harvard Medical School, Boston, MA), the study’s lead author, told TCTMD.

Also known as Medicare Part C, MA was launched in 2003 as an alternative to traditional Medicare that is advertised as a way for U.S. patients ≥65 years of age to obtain additional healthcare services at lower cost. Some MA plans offer zero premium and coverage for things Medicare doesn’t cover, like vision, hearing, and dental visits. However, MAID plans tend to be more restrictive in terms of the providers patients can see and may require prior authorization for drugs or procedures. individuals can enroll in MA when initially enrolling in Medicare, or can switch during annual open enrollment periods.

While previous studies comparing acute MI treatment regimens between traditional Medicare beneficiaries and NI beneficiaries have found little difference, questions remain about disparities in care and mortality in light of the unprecedented growth of the new insurance option.

“Managed care plans have many tools to improve care efficiency and patient management. So we wanted to see how differently patients, at least with that particular clinical condition as a starting point, were managed in Medicare Advantage and traditional Medicare,” Landon said.

The analysis, which spanned 2009 to 2018, found that STEMI and NSTEMI patients had lower 30-day mortality rates at the start of the study period if they were on MA compared to traditional health insurance. By 2018, the differences had dissipated, although AD patients had a higher likelihood of receiving and adhering to guideline-compliant medication after discharge, less resource use, and fewer repeat hospitalizations, and were more likely to be sent home than to a post-acute care facility.

“To the extent that MA plans have been able to work with hospitals and providers to do things that make health care delivery less expensive by not using post-acute care as much, by not having as much of readmissions, I think that’s a positive thing for society, and that will ultimately be reflected in the premiums that come with Medicare Advantage plans to some degree,” Landon said.

Tracking Changes in AD Patients and Outcomes

For the study, Landon and colleagues analyzed data from more than 2.2 million patients with acute MI (mean age 78 for STEMI and 79 for NSTEMI; 42% female). While Medicare and AD patients were mostly well matched at baseline, diabetes was more common in the AD group with STEMI in 2009 and 2018.

Even after adjusting for age and sex, MA enrollment was associated with a lower 30-day mortality rate for STEMI in 2009 (18.4% vs. 20.7%) compared to traditional health insurance. The difference remained after further adjustment for race/ethnicity and factors related to Medicare eligibility. At the 2018 time point, mortality rates were lower than in 2009 for the AD and traditional Medicare groups, with no significant difference (17.7% versus 17.8%). A similar trend was observed in NSTEMI patients.

Landon said it is very likely that the early benefit attributed to AM could be explained by some residual unmeasured differences in health status which, as the population of AM grew and became more like the traditional Medicare population, had less impact on outcomes over time.

In 2009, PCI rates for STEMI were 62.7% in the AD group versus 59.6% in the traditional Medicare group, with no difference seen in 2018. CABG rates decreased in the AD group over time. time, but were not significantly different from the traditional Medicare group. group by 2018.

In terms of resource utilization, the MA group had fewer inter-hospital transfers in 2009 and 2018 compared to traditional Medicare, as well as fewer ICU admissions. Return home was 71% for the AD with STEMI group and 67.3% for the traditional Medicare group, a 3.7% gap that narrowed to 1.3% in 2018, when rates were of 71.5% and 70.2%, respectively. No difference was observed in length of stay between plans at either time. Adjusted readmission rates within 30 days of discharge were lower in the MA group in 2009 and 2018.

Regarding the NSTEMI group, PCI was more common in AD patients in 2018 than in the traditional Medicare group (69.1% vs. 67.8%), with similar patterns of lower resource utilization and less readmissions than the STEMI group.

During both time periods, AD patients with STEMI and NSTEMI had higher rates of prescriptions filled than those with traditional Medicare, but the differences narrowed over time. Among those who filled a prescription, adherence was generally higher in the MA group than in traditional health insurance throughout the study period, but the differences narrowed over time.

The number of hospitals receiving AD patients treated for STEMI or NSTEMI increased over the study period, resulting in a lower concentration of AD patients in some centers in 2018 than in 2009.

Concerns over overpayments and plan differences

MA is not without controversy, with a recent New York Times article noting continuing concerns about inflated billing and missing documentation, as well as allegations of fraud against some of the plan’s private insurers.

In an accompanying editorial, David J. Meyers, PhD (Brown University School of Public Health, Providence, RI), and colleagues note that with the intention of becoming the dominant form of Medicare coverage in the future, MA should be redesigned to reduce overpayments. and provide high value care.

Variation within MA plans also deserves more attention, write Meyers and colleagues. “While most of the prior literature has made simple binary comparisons between enrolling in Medicare Advantage or traditional Medicare, hundreds of different contracts and insurers administer Medicare Advantage, and there are thousands of plans that vary in benefit design, physician networks, care coordination, and business strategies,” they add. Leaving this aspect unaddressed leaves significant gaps in understanding “how the successes of high-performing plans can be replicated in less successful plans and whether certain types of plans are better equipped to meet the challenges of certain groups of enrollees”.

Landon told TCTMD the point is well understood.

“There’s a lot of heterogeneity among the MA planes, so it’s true that you can’t consider it a singular entity because it really isn’t,” he said. “More work needs to be done in the future to understand if there are some health plans that actually do a better job than others. But obviously anytime you get to smaller sample sizes associated with a single health plan, you have issues with sample size and statistical issues.

Meyers and colleagues also point out that since much of the growth in AD enrollment has occurred among racial and ethnic minority patients, another priority should be to get a better picture of equity in care provided in MA plans compared to traditional health insurance.