In stark contrast to a 2010 investigation suggesting that nurse anesthetists frequently provide care unsupervised by physician anesthesiologists, researchers at the University of Texas Medical Branch and the American Society of Anesthesiology’s (ASA) Department of Health Policy have found that the Medicare billing code at the center of that trial—modifier QZ—does not seem to be a valid surrogate for care in which no anesthesiologist is present. These findings, the investigators concluded, call into question the validity of prior research.
“The Dulisse and Cromwell study [Health Aff 2010;29:1469-1475] started with a false premise,” said Amr Abouleish, MD, MBA, professor of anesthesiology at the University of Texas Medical Branch in Galveston. “They assumed that the QZ modifier only represents CRNAs working without an anesthesiologist—and we all know that is wrong.”
Indeed, as Dr. Abouleish reported, nurse anesthetists have two coding options—modifiers QX and QZ—when billing for care of Medicare patients. Modifier QX is used when a physician anesthesiologist provides medical direction, a high level of care. Modifier QZ, in contrast, is used when care is provided in several different ways, including when:
- a nurse is supervised by a physician anesthesiologist or another physician;
- a nurse works without supervision; or
- a physician anesthesiologist provides high-level care with limited documentation.
To test the hypothesis that modifier QZ represents solo nurse anesthetist care, the investigators examined claims from 538 hospitals where every anesthesia claim used the QZ modifier. Yet despite the fact that all 9,071 anesthesia claims used only the modifier, physician anesthesiologists were affiliated with 47.5% of these hospitals.
“Our premise,” Dr. Abouleish said in an interview with Anesthesiology News, “is that if there’s an anesthesiologist on staff for those facilities, he or she is going to be providing anesthesia care for at least some Medicare cases. It would not be logical for these hospitals to have anesthesiologists on staff and not provide any patient care.”
As Dr. Abouleish explained, nurse anesthetists and physician anesthesiologists working at the same institution typically have a formal working relationship that may include collaboration, consultation, rescue from critical events or supervision.
“I want to make it clear that I strongly appreciate nurse anesthetists working in the anesthesia care team model,” he said. “I think they’re great partners; we work great as a team.”
The problem, Dr. Abouleish explained, lies with Medicare billing policies, which hinder physician anesthesiologists from billing when supervising nurse anesthetists. “The challenge is that if you employ and supervise nurse anesthetists, the nurse anesthetist is going to bill out the QZ modifier and get 100% payment allowed from Medicare. If the physician anesthesiologist bills out the supervision code, all of a sudden Medicare is paying more than 100% of allowable. That’s a quandary, because these groups don’t want Medicare to pay them for more than the 100% allowable for a service,” Dr. Abouleish said.
Hospital Staffing Issues
The issue becomes even more acute when the Dulisse and Cromwell study, along with a 2003 trial that was built around the same premise (AANA J2003;71:109-116), are cited as evidence that nurse anesthetist stand-alone care is equivalent to care involving a physician anesthesiologist. As such, these trials are frequently used to influence hospital staffing policies. “The upshot of this is that we really shouldn’t be using Dulisse and Cromwell as the foundation of policy since the study results are based on a false premise,” he said.
Using the 2003 and 2010 trials in this way may ultimately diminish patient care by allowing nurse anesthetists to administer anesthesia without the supervision of physician anesthesiologists. “If you ask me what’s the best way to provide care, I say it’s demand matching,” Dr. Abouleish noted. “And if that means I have to be in the room 100% of the time, then I have to be in the room 100% of the time. And if I don’t have to be there 100% of the time, I’ll work with my team to do that, too.”
Dr. Abouleish was quick to disclose that the current trial was funded by the ASA. “Nobody is claiming that ours is the best study,” he said. “We just wanted to answer a simple question. This analysis is our way of showing that the billing modifier QZ is invalid as a surrogate for nurse anesthetist stand-alone practice. Therefore, it’s impossible to use modifier QZ to compare patient outcomes from nurse anesthesia–alone care to physician anesthesiologist care.”