Author: Chase Doyle
Cognitive complications arising postoperatively in cardiac surgical patients impose a significant clinical and economic burden, according to a new analysis of discharge data from 650 hospitals across the United States. The retrospective study showed that the incidence of neurocognitive dysfunction was five times more frequent than stroke following cardiac surgery, and had a similar effect on increased hospital length of stay and hospital cost. Efforts to improve the management of neurologic complications after cardiac operations could dramatically reduce health care costs while improving patient outcomes and quality of life, the researchers reported.
“It costs as much to take care of a patient with postoperative cognitive complications as it does to take care of a patient who has had a stroke, yet cognitive complications are five times as frequent,” said Albert Cheung, MD, a professor of anesthesiology, perioperative and pain medicine (cardiac) at Stanford University Medical Center, in California. “When you consider that there are roughly 1 million cardiac surgical patients over a five-year period, and 5% to 10% of those patients may develop neurocognitive complications, that’s a $1.5 billion increase to the cost of care. That’s a huge economic burden on the health system.”
For this study, Dr. Cheung and his colleagues used the Premier database (Premier Inc.) to analyze discharge data for cardiac cases from 650 hospitals. The researchers included all patients undergoing isolated coronary artery bypass graft (CABG) surgery, isolated valve or CABG–valve procedures performed using cardiopulmonary bypass. Patients who had preexisting stroke or neurocognitive dysfunction were excluded. The incidence of postoperative stroke was identified through International Classification of Diseases 9-CM codes and hospital charges, but because the incidence of delirium in administrative databases is often underestimated, Dr. Cheung said, the researchers identified patients with postoperative delirium or those who received antipsychotic medications in the postoperative period as patients with postoperative cognitive complications (POCC).
As Dr. Cheung reported at the 2018 annual meeting of the Society of Cardiovascular Anesthesiologists (abstract 8), the overall incidence of postoperative stroke was 1.50% among patients who did not have a history of prior stroke, while the overall incidence of POCC was five times more frequent at 7.56%. At the same time, both postoperative stroke and neurocognitive complications significantly increased hospital total care costs and length of stay.
Postoperative stroke increased total hospital cost of care by a factor of 1.59 or $27,643 (P<0.001), while POCC increased total hospital cost of care by a factor of 1.60 or $27,397 (P<0.001). Although patients who experienced stroke had a higher likelihood of dying during hospitalization than those with neurocognitive complications (8% vs. 2.5%), mortality was still increased 2.2-fold in patients with POCC over those without neurologic complications.
The researchers also emphasized that morbidity and cost of care extend beyond the index hospitalization, as fewer patients with stroke or POCC were discharged to home or home health care. As Dr. Cheung reported, 61% of patients who had a stroke and nearly half (49%) of those with POCC needed to be sent to another facility after discharge.
“The majority of patients who had a stroke could not be discharged home or to home health care, and the numbers were very similar for patients with neurocognitive complications,” Dr. Cheung said. “Studying only the cost of the index hospitalization or the hospital length of stay significantly underestimates the total cost of care, which extends beyond hospital discharge.”
Finally, patients with stroke or POCC had greater comorbidity at the time of discharge, indicating a decrease in long-term survival of 25% for stroke and 5% to 10% for POCC.
“When patients have cognitive complications, it’s not just a problem in the hospital; it’s also a problem after they get discharged,” Dr. Cheung said. “So, it’s obviously important to minimize these complications in the hospital.”
He added, “While it would be nice to be able to prevent these complications entirely, we can also make a huge impact by decreasing the severity of these complications when they occur.”
Although the Premier database covers approximately 20% of all hospitalizations in the United States and takes into account both insured and uninsured patients, the researchers acknowledged limitations in using retrospective data, namely the inability to interpret cause and effect. Nevertheless, Dr. Cheung said, these data do provide a reference for future quality improvement efforts.
“Whether decreasing the cost by 10%, or decreasing the hospital length of stay by one or two days, or decreasing the incidence by 0.5%, every improvement will make a big difference based on the existing situation as characterized by this retrospective study. I think this study highlights the importance of this problem and the need to direct efforts toward addressing this ongoing problem,” Dr. Cheung concluded.