A team of researchers who analyzed rates of do-not-resuscitate (DNR) orders in California are suggesting DNR mortality numbers should be taken into account when calculating hospital risk-adjusted heart failure mortality metrics.

Current methods used to compare and assess hospitals don’t take patients’ DNR status into account, lead author Jeffrey Bruckel, MD, MPH, and colleagues wrote in a study published in the Journal of the American College of Cardiology: Heart Failure. This isn’t ideal, since DNR orders vary across hospitals and tend to predict higher in-hospital mortality. Higher mortality rates could mean lower national rankings for hospitals, resulting in funding cuts and other issues.

The U.S. pours $30.7 billion into medical care for heart failure annually, according to Bruckel’s research, and heart failure hospitalizations are a focus of the Centers for Medicare and Medicaid. For many cardiovascular patients, though, that’s not enough. Some individuals among the one million annually admitted heart patients suffer from advanced heart failure, which can come hand-in-hand with lower quality of life and additional comorbidities. In these cases, patients might request a DNR order—called an “early DNR” if the request is submitted within 24 hours of hospital arrival.

“Failure to account for patient DNR status when determining hospital mortality rates may strongly impact hospital mortality measurements and, thus, hospital rankings,” Bruckel and co-authors wrote.

The team drew medical data from 55,865 patients documented in the California State Inpatient Database and analyzed DNR rates and their possible impacts on a hospital’s risk-adjusted heart failure mortality score. The patients spanned across 290 hospitals in the state, and Brucknel’s team focused on 2011.

More than 12 percent of the total studied population requested an early DNR order, the researchers reported. Older patients and those diagnosed with dementia, metastatic cancer and leukemia were more likely to order a DNR, while men and individuals living with acute coronary syndrome, arrhythmia and diabetes saw lower rates of DNR use.

The average hospital DNR rate was 8.7 percent, Bruckel and co-authors wrote, but those numbers ranged from 0 percent to 53.8 percent. While in-hospital mortality in all patients was 3.1 percent, patients with DNR orders had a 9.9 percent mortality rate. Just 2.1 percent of patients without a DNR died in-hospital.

“Because patient DNR status within 24 hours of admission was strongly associated with hospital mortality, and DNR order rates showed more than threefold variation among hospitals, accounting for patient DNR status strongly influenced hospital risk-standardized mortality rates,” the authors wrote. “The hospital to which a patient was admitted was more strongly associated with receipt of a DNR order than the strongest clinical predictors in the model.”

The clinical predictors included age, dementia and metastatic cancer, Bruckel and colleagues explained. Their findings mirrored a previous study, which identified DNR status as the strongest determinant of 6-month mortality after critical illness.

Because hospital scores and risk-adjusted mortality ratios are public record, they’re often reported and influence hospitals’ reputations and reimbursement. Omitting DNR orders from risk-adjusted mortality measurements could skew rankings, the authors wrote, giving the public a slanted view of a hospital’s quality of care.

DNR is a suitable option for many patients, they said, and the fact that health systems with higher DNR use rates are penalized because of higher mortality rates might not be fair. Hospitals with higher DNR use could potentially be more patient-centered; on the other hand, they could be overusing DNR orders.

“Because mortality statistics are publicly reported and affect hospital reimbursement, accuracy in measuring and reporting these outcomes are essential,” Brucknel and colleagues wrote. “Failure to appropriately account for patient DNR status at hospital admission in risk models may discourage programs from eliciting patient preferences for life support therapy, as hospitals with more patients selecting limitations on life support have higher mortality rates that result in financial penalty.”