JACC: CABG mortality down, readmissions remain up
CABG surgery carries an estimated price tag of $100,000 per admission. And researchers from University of Albany in New York have found that 30-day readmission rates for this costly procedure are high despite the fact that mortality rates have decreased. The study, published in the May issue of JACC: Cardiovascular Interventions, set out to better understand what causes CABG readmissions in hopes of avoiding them, and found that infection may be the number one problem.

“Hospital readmissions within a short period after initial discharge occur frequently and add substantial costs to the healthcare system of our country,” wrote Edward L. Hannan, PhD, of the University at Albany, State University of New York in Albany, N.Y., and colleagues. One of the main visions under the healthcare reform bill is reducing unnecessary healthcare costs and one strategy is avoiding unnecessary readmissions.

Hannan et al analyzed data of 33,936 New York patients who underwent CABG between Jan. 1, 2005, and Nov. 30, 2007, to identify the reasons for CABG readmissions within 30 days after a hospital discharge.

The rate of 30-day all-cause readmission was 16.5 percent, with a range of 8.3 percent to 21.1 percent across the hospitals. They noted that 87.3 percent of these 30-day readmissions were related to CABG surgery. Less than 3 percent of patients readmitted to the hospital died.

Post-operative infection, heart failure, surgical and medical care complications, cardiac dysrhythmia and angina/chest pain were the most frequent reasons for hospital readmission within 30 days of discharge and occurred at rates of 16.9, 12.8, 9.8, 6.3 and 4.7 percent, respectively.

Those readmitted to the hospital were more likely to be older, female, African-American, have a higher body mass index and multiple comorbidities. Additionally, these patients were more often on Medicare or Medicaid and released to a skilled nursing facility, received a saphenous vein graft and experienced a longer length of stay.

The authors noted that targeting interventions around patient characteristics will not significantly lower hospital readmissions and a focus on system-related factors like coordination with outpatient care that were not measured, should be undertaken. “Patient characteristics may be associated with readmission, but they explain only a small proportion of the variance in the outcome and tend to be nonmodifiable (e.g., age),” wrote John S. Rumsfeld, MD, PhD, and Larry A. Allen, MD, MHS, of the Denver Veterans Affairs Medical Center and University of Colorado Anschutz medical Campus in Aurora, Colo., in the accompanying editorial.

Hannon and colleagues called it “interesting” that 30-day readmissions rates were still on the rise despite the quality improvement initiatives the state of New York has integrated with the past couple of years. While mortality rates in the states dipped from 2.24 percent in 1999 to 1.54 percent in 2007, readmission rates remain high. Additionally, they called the correlation between the risk-adjusted in-hospital/30-day mortality rates of hospitals and risk-adjusted readmission rates "notable" and reported that it was 0.32.

“Hospital readmissions are not highly correlated with hospital short-term mortality rates and consequently might serve as another independent quality-of-care measure,” the study authors concluded. They added that part of the reason that readmission may not have decreased even though mortality rates had could be due to the fact that efforts to coordinate inpatient and outpatient care are “insufficient.”

The healthcare system must find a way to work provide effective, necessary care at a lower cost. The short answer to improving care will lie in improving institutional quality of care and reverting from the current healthcare system where hospitals are still incentivize for readmission.

“Complication rates for CABG surgery are long-standing, validated quality measures, and the variability in readmission rates between institutions is a strong argument that some of these readmissions are preventable," wrote Rumsfeld and Allen.

The editorialists also wrote that the U.K., whose healthcare system focuses more on quality measurements and improvement, sees better outcomes in terms of cardiac surgery compared with the U.S., and even other parts of Europe. The system better utilized transitions of care and cardiac rehabilitation compared with other parts of the country.

“In an environment in which consumer groups, clinicians, hospitals, health systems and payors are highly cognizant that readmission rates are being emphasized as measures of quality and will be tied to reimbursement, the study by Hannan et al provides a simple but powerful message: we must work for evidence-based reductions in unnecessary rehospitalization,” Rumsfeld and Allen wrote. “As such, efforts to reduce procedural complication rates and improve transitions of care should be centric to quality improvement. If that happens, it may not only help the financial bottom line of hospitals and the country, but more important, it can help individual patients and their families.”