For the past few years, the Centers for Medicare & Medicaid Services (CMS) has tracked 30-day readmissions rates for heart failure, acute MI and other conditions that account for a large percentage of readmissions. Hospitals that have excessive readmissions are subject to penalties.

Still, when it comes to readmissions for non-Medicare or Medicaid patients, there is a scarcity of data available. Recently, though, researchers examined the 2013 Nationwide Readmissions Database, which accounts for inpatient hospitalizations in 21 states and represents 49 percent of the U.S. population.

Their conclusions? Readmissions are not only frustrating and potentially devastating for patients, but they are also expensive for whoever is footing the bill.

Of the more than 14 million hospitalizations in the database, the researchers identified more than 1.1 million admissions that were associated with unplanned 30-day readmissions. Of the readmissions, 1.3 percent of patients were diagnosed with acute MI and 6.7 percent were diagnosed with heart failure.

The mean length of stays in the hospital were 5.7 days for acute MI and 6.4 days for heart failure, while the mean costs per readmission were $9,424 and $9,051, respectively.

The results were similar when the researchers performed sensitivity analyses based on expanded CMS discharge fields. With that criteria, they found that the mean length of stays in the hospital were 6.0 days for acute MI and 6.5 days for heart failure, while the mean costs per readmission were $9,530 and $9,248, respectively.

The researchers acknowledged that the National Readmission Database only used state-specific identifiers, so they could not follow-up patients across states. Thus, the readmission rates could have been higher. Still, the study should help hospitals, physicians and patients understand the economic impact of readmissions for two common cardiovascular conditions.