By MICHAEL MILLENSON

“Money changes everything,” Cyndi Lauper famously sang about love to a pulsating rock ‘n’ roll beat. So, too, when it comes to financial incentives for surgeons, two new studies suggest, although “How much money?” and “What do I have to do?” are the keys to unlocking monetary motivation.

The first study, a JAMA research letter, examined the impact of a new Medicare billing code for abdominal hernia repair that paid surgeons more if the hernia measured at least 3 centimeters in size. Previously, “size was not linked to hernia reimbursement,” noted University of Michigan researchers.

Surprise! The percentage of patients said to have smaller, lower-payment hernias dropped from 60% to 49% in just one year. Were “small hernia” patients being denied care? Nope. Were surgeons perhaps more precise in measuring hernia size? Maybe. Or possibly, wrote the researchers in careful academic language, “the coding change may have induced surgeons to overestimate hernia size.” Ambiguous tasks, they added, “can be conducive to perceptive [cq] bias and potentially even dishonest behavior, perhaps more so with financial incentives at play.”

This being an academic publication, two footnotes informed us that dangling money in front of our eyes can cause people to “see what you want to see” and come up with an “elastic justification” for truth.

If a simple coding change can apparently boost the number of large-hernia patients by 18% in just one year, what about a payment incentive meant to induce more urologists to follow the medical evidence on low-risk prostate cancer and adopt “active surveillance” (formerly known as “watchful waiting”), rather putting patients through a painful and expensive regimen of biopsies and surgery?

A second study, also in Michigan, involved commercial and Medicare-age members of the state’s Blue Cross and Blue Shield plan. However, after three years and more than 15,000 patients, “the payment incentive was not associated with increased surveillance use among patients with low-risk disease,” researchers concluded in a JAMA Network Open article.

A financial incentive fails

This inertia belied the enormous potential for improvement. A previous study found active surveillance for low-risk prostate cancer patients among Michigan urology groups – a rate adjusted for the patient’s clinical condition – ranged from 30% to 73%. In one urology practice, the rate among individual clinicians – a half-century after the first studies of practice variation practice variation among similar doctors with similar patients – ranged from zero to 96%!

Yet even in those physician groups with the lowest rate of active surveillance use and the highest proportion of patients from Blue Cross – the groups expected to be most “sensitive” to a financial incentive – there was no statistically significant change. Why?

Once again, the researchers carefully noted that surgical treatment decisions “may be partly driven by nonclinical factors, including financial incentives.” For instance, “physicians may make thousands of dollars more in the first year through primary treatment as opposed to active surveillance.” Moreover, for any individual surgeon to actually receive the health plan’s financial incentive, the entire urology group had to meet a target requiring almost three-quarters of men eligible for active surveillance to either be offered it as an option or accept it.

For all the loud proclamations by payers, providers and policymakers that the U.S. healthcare care system is well on its way to “value-based payment,” the pronouncements about an emphasis on patient preferences and the “cost-quality equation” remain just that empty words when compared to the concrete value signified by an immediate paycheck boost. When a new billing code pays more to individual surgeons, significant change swiftly follows, even if only in documentation. Roll out a convoluted payment scheme that requires an entire surgical group to alter its doctors actually practice, however, and very little happens.

The “effective” way “to align prostate cancer care quality with payment,” the researchers concluded, may require “reimbursement parity between [low-risk prostate cancer] management strategies.”

In other words, if you want financial incentives for surgeons to really work, it pays to remember a declaration a Tom Cruise film made famous: “Show me the money.”

Michael L. Millenson is president of Health Quality Advisors & a regular THCB Contributor. This originally appeared on Forbes.