Avoidable Hospitalizations Less Common in Medicare Advantage, Study Finds

Medicare Advantage beneficiaries were less likely to have avoidable hospitalizations than those in traditional Medicare, suggesting that the use of provider networks in Medicare Advantage may reduce unnecessary healthcare utilization, according to a study published in JAMA Health Forum.

A key difference between Medicare Advantage and traditional Medicare is the private program has provider networks that, on average, limit beneficiaries to visit around 40 percent of local physicians for in-network care.

Physicians play an essential role when it comes to avoiding hospitalizations for ambulatory care-sensitive conditions (ACSCs) like diabetes and hypertension.

Researchers used 2018 and 2019 Medicare Advantage encounter data and traditional Medicare claims data to assess whether avoidable hospitalization differences between the two programs could be attributed to the primary care clinicians that beneficiaries visit. They limited the data to beneficiaries with one or more of five chronic ACSCs: diabetes, chronic obstructive pulmonary disease (COPD), asthma, hypertension, and heart failure.

The sample included 1.3 million Medicare Advantage beneficiaries and 1.9 million traditional Medicare beneficiaries. Hypertension was the most common ACSC among all beneficiaries (91.1 percent), followed by diabetes (37.4 percent), COPD (15.1 percent), heart failure (14.2 percent), and asthma (6.8 percent).

The majority of the 110,594 clinicians attributed to the beneficiaries were primary care physicians (74 percent) or nurse practitioners and physician assistants (21 percent).

The unadjusted rate of avoidable hospitalizations was highest among beneficiaries with heart failure at over 6 percent and lower among those with hypertension at 0.3 percent. More than 2 percent of all beneficiaries had an avoidable hospital stay in 2019 due to any of the ACSCs.

The unadjusted relative risks suggested that Medicare Advantage beneficiaries with diabetes, COPD, and heart failure were 3 percent to 9 percent less likely to have avoidable hospital stays than traditional Medicare beneficiaries. However, Medicare Advantage beneficiaries with asthma and hypertension were 12 percent and 5 percent more likely to have avoidable hospitalizations. The overall rate of avoidable hospitalizations was 3 percent lower in Medicare Advantage.

After adjusting for chronic conditions, Medicare Advantage beneficiaries were 1.9 percent less likely to have avoidable hospitalizations than traditional Medicare beneficiaries.

The researchers also added clinician-fixed effects, after which the rate of avoidable hospitalizations was 2.3 percent lower in Medicare Advantage. When they estimated the mean difference between the two programs within a clinician, the average rate was the same.

These findings indicate that the estimated difference between Medicare Advantage and traditional Medicare was due to Medicare beneficiaries sorting to different clinicians, researchers wrote. Furthermore, the study found that Medicare Advantage beneficiaries were more likely than traditional Medicare beneficiaries to visit clinicians with lower rates of avoidable hospital stays and avoid those with higher rates.

Although provider networks may limit access to certain clinicians, they can also benefit beneficiaries by steering them to high-quality providers, such as those with lower rates of avoidable hospital stays. In addition, narrow provider networks have been associated with higher Medicare Advantage contract star ratings, the researchers noted.