For many privately insured patients, undergoing elective surgery carries an unanticipated risk: a substantial extra bill.

According to an analysis of claims data from a large commercial health insurer, more than 1 in 5 elective procedures result in liability for out-of-network costs, with an average surprise bill of just over $2011.

In many cases, these unexpected charges relate to the services of clinicians not in the patients' health coverage networks, including anesthesiologists, surgical assistants, pathologists, medical consultants, and radiologists. Although for elective procedures, patients can usually choose an in-network surgeon at an in-network facility, they do not have the opportunity to approve of receiving services from out-of-network providers, nor to avoid them.

The study appears online today in JAMA.

The retrospective analysis was based on figures from the Clinformatics DataMart. The researchers included nearly 347,356 privately insured patients aged 18 to 64 years who underwent 1 of 7 common elective surgeries from 2012 to 2017 at in-network facilities with in-network primary surgeons. Operations included arthroscopic meniscal repair, laparoscopic cholecystectomy, hysterectomy, total knee replacement, breast lumpectomy, colectomy, and coronary artery bypass grafting. The mean age of patents was 48 years, and 66% were women.

Overall, the authors found that in 20.5% of extra billing episodes (95% confidence interval [CI], 19.4 – 21.7), patients received an out-of-network bill.

"Although anesthesiologists are often cited as the most common source of out-of-network bills in surgery, the current analysis found that out-of-network bills from surgical assistants had a similar frequency (37% of episodes) and were significantly larger than those from anesthesiologists ($3633 vs $1219)," write Karan R. Chhabra, MD, of the Institute for Healthcare Policy and Innovation at the the University of Michigan in Ann Arbor and Brigham and Women's Hospital in Boston, Massachusetts, and colleagues.

The analysis also shows that membership in health insurance exchange plans correlated with a significantly greater risk for out-of-network bills compared to non-exchange plans: 27% vs 20%.

In addition, the researchers found that surgical complications correlated with a significantly higher risk for out-of-network bills compared to procedures in which there were no complications, at 28% vs 20%.

Of 83,021 procedures at ambulatory facilities with in-network primary surgeons, 6.7% (95% CI, 5.8 – 7.7) entailed an out-of-network facility bill, and 17.2% (95% CI, 15.7 – 18.8) entailed an out-of-network professional bill.

"These findings suggest that, in surgical settings, the problem of out-of-network billing is not restricted to a single specialty or setting," the authors write. They point out that surgical care is by nature multidisciplinary and involves a clinical team whose payer contracts are usually not coordinated. "This is in contrast to prior research on emergency care, which pointed toward a subset of emergency departments staffed by private equity–backed medical groups as the primary source of out-of-network billing," Chhabra and colleagues continue.

Most previous studies on unexpected out-of-network billing have involved emergency department care or general inpatient care, in which patients do not have the same latitude to select in-network providers as elective surgery patients.

The authors acknowledge that their study is limited by its reliance on claims data from a single health insurer but note that there is increasing concern regarding surprise billing. Last year, Medscape Medical News reported on a bipartisan bid for a federal law to support independent arbitration for disputed out-of-network surprise bills.

An editor's note, published alongside the new study in JAMA, calls for concerted action on surprise billing. "Such billing practices are particularly pernicious because patients usually have no knowledge that they will occur, and no way to avoid them," write Karen E. Joynt Maddox, MD, MPH, and Edward Livingston, MD, associate and deputy editor, respectively, of JAMA. "Clinicians and policy makers alike should act to end this practice."

According to Livingston and Joynt Maddox, who is also an assistant professor of medicine at Washington University in St. Louis, Missouri, surgeons have an ethical duty to decry this practice, and failure to do so will erode patients' critical trust in their surgeons.

"When feasible, surgeons should ensure that all the personnel involved in the care team that they are leading accept the same insurance plans and should consider refusing to work in facilities that allow surprise billing," they write.

On the legislative front, the commentators call for federal action to prohibit surprise billing. Although some states have passed anti–surprise billing legislation, the editorialists note that Chhabra and coauthors found that state policies had no impact on patients' financial liability for out-of-network charges.

They further point out that physician groups ― particularly those backed by private equity firms ― have pushed back against recently proposed legislation in the House and the Senate that would make patients liable only for in-network cost-sharing, such as deductibles or copays. Livingston and Joynt Maddox conclude that although it is important to consider clinicians' concerns about fair reimbursement, "it is crucial that patients' interest remain paramount."

The study was supported by the University of Michigan Institute for Healthcare Policy and Innovation Policy, which also supported Chhabra. A coauthor is a cofounder of ArborMetrix Inc, a manufacturer of software for profiling hospital quality and efficiency. Joynt Maddox has received support from government health agencies and the Commonwealth Fund.

JAMA. Published online February 11, 2020.

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