Infections after heart surgery can raise costs by $38,000

Major healthcare-associated infections (HAIs) up to two months after cardiac surgery may tag an additional $38,000 to the cost of the index hospitalization, a finding that researchers propose may spur hospitals to invest in preventive measures.

Giampaolo Greco, MD, of Mount Sinai Medical Center in New York City, and colleagues published the results of a cost analysis in the Jan. 6/13 issue of the Journal of the American College of Cardiology. The study differed from other research in design and scope. Rather than rely on billing data, they linked clinical data from the nine U.S. centers participating in the Cardiothoracic Surgical Trials Network with patient-level economic data from the centers or the University HealthSystem Consortium. They looked beyond the usual 30-day window for follow-up to 65 days.

Greco et al identified 4,614 patients who underwent cardiac surgery between February and October 2010, of whom 4,320 had financial records. Of those patients, 4.5 percent developed HAIs, with 151 events in the index hospitalization and 99 with rehospitalization. Almost half of the major HAIs were pneumonia.

Compared with patients with no major HAI during their index hospitalizations, patients with HAIs had longer average length of stay (mean 33 days vs. nine days) and higher costs (mean $110,155 vs. $31,530). The adjusted additional cost for major HAIs totaled $37,513 (2010 dollars), with about half of the costs attributed to intensive care.

Greco et al found a 15 percent 30-day readmission rate overall, with 9.1 percent identified as due to major infections. Not including rehabilitations and emergency department visits, they calculated an overall readmission rate with the longer follow-up of 19.7 percent, with 8.7 percent attributed to major HAIs. Compared with other readmissions, HAI-related readmissions were longer (11.5 days vs. six days) and more costly ($33,512 vs. $12,742).

Readmission rates serve as an indicator of quality, Greco and colleagues observed, and the Centers for Medicare & Medicaid Services already penalizes hospitals with higher than expected 30-day readmission rates for heart failure, acute MI and pneumonia. The agency anticipates adding 30-day CABG readmissions to the list as early as 2017.

“This study, therefore, substantiates the economic argument for preventive interventions and specifies the possible economic returns from such strategies,” they wrote. “This information may help to drive quality-improvement initiatives to reduce HAIs and ultimately improve patient outcomes.”

Vinay Badhwar, MD, of Presbyterian University Hospital in Pittsburgh, and Jeffrey P. Jacobs, MD, of All Children’s Hospital in St. Petersburg, Fla., cautioned in an accompanying editorial that including transplant and ventricular assist device patients who already were at high risk for infections and readmissions created “an apples-to-oranges, or at least an apples-to-pears, comparison. Before recommendations are made about how the development of infections following cardiac surgery might be addressed in health care policy and hospital-level reimbursement, further procedure-specific granularity is required.”

The Society of Thoracic Surgeons and the Centers for Disease Control and Prevention are working together to clarify and harmonize definitions of infections specific to cardiac patients for use in determining rates, Badhwar and Jacobs wrote.