Primary-care practitioners tend to overestimate the risk of common conditions based on symptoms and test results, leading to potentially excessive and harmful care, a new study shows.
Residents, attending physicians, nurse practitioners and physician assistants estimated a 70% likelihood of cardiac ischemia in patients who had a positive stress test when the actual likelihood is 2% to 11%, researcher's analysis of 533 practitioners found. Survey respondents also estimated a 50% risk of breast cancer after a positive finding on a mammogram when evidence shows only a 3% to 9% risk.
There was a similar trend in urinary tract infection diagnoses, with practitioners projecting an 80% likelihood of a UTI after a positive urine culture when the real risk is at most 8%, according to the study published in JAMA.
"This certainly indicates the tendency to overestimate the chance of disease both before a test is ordered and after a test is obtained," said Dr. Daniel Morgan, lead author of the study and epidemiology professor at the University of Maryland School of Medicine. "At least we teach that we should practice based on estimates of probability—but in real life that is not rewarded that much."
Practitioners surveyed were often residents or academic physicians who typically work with sicker patients, which may have contributed to the inflated probability estimates, researchers noted. But that wouldn't explain the significant gap in probability estimates and evidence-based projections, Morgan said.
One cannot rule out the perverse incentives of fee-for-service medicine as it relates to excessive care, given that most providers are reimbursed per test or procedure, he said, adding that the threat of malpractice claims can also factor into treatment. While doctors are primarily concerned with a patient's health rather than payment, low-value habits are driven by electronic health records and standard operating procedures, Morgan said.
Patients may also pressure providers for more tests. But not only can these tests be wasteful, they can also lead to real harm, he said.
"Testing can help, but it can also confuse a situation," Morgan said, pointing to the example of a patient with chest pain. "Even though those patients are extremely low risk for cardiac ischemia, they may get a coronary catheter, which carries not an insignificant chance of an adverse event. It's horrifying that we may be doing that to some people a proportion of the time with no potential for any benefit."
Low-value care can account for roughly one-quarter of all U.S. healthcare spending, some estimates show.
Sometimes treatment is equated with receiving a test, antibiotic or other medicine even when their likelihood to help is minimal. Providers and patients should spend more time discussing symptoms and treatment options rather than jump to a test, Morgan said, who also recommended a greater emphasis on diagnostics and probability during training.
"It takes a lot more effort to talk with patients about what they are thinking is happening versus sending for a test and telling them what they have or don't have based on the result," he said, adding that his research has changed the way he practices. "We may need to have a bit more humility, not jump to conclusions quite as quickly and ask before a test — is this going to help?"
The healthcare workforce is shifting, which could also influence care patterns. More advanced practice practitioners are entering the field as stakeholders across the field expand their primary care offerings.
Nurse anesthetists, nurse practitioners and nurse midwives are projected to grow 45% from 2019 to 2029, according to the Bureau of Labor Statistics, pegging physician assistants' growth at 31% over that span. COVID-related waivers adjusting scope of practice laws and telehealth regulations have supported that trend.
"Expansions in urgent care centers, retail clinics and telehealth will further increase the demand for nurse practitioners," Linda Aiken, director of the University of Pennsylvania Center for Health Outcomes and Policy Research, told Modern Healthcare last month. "The demand for nurse practitioners is also strong and growing in inpatient settings."
Advanced practice practitioners are filling a shortage of primary-care physicians. While there was an estimated shortage of 20,400 primary-care physicians in 2020, the supply of NPs and PAs grew by 30% and 58% respectively, outstripping a 17% increase in combined demand, according to the Health Resources and Services Administration. The NP workforce more than doubled from 2010 to 2017.
Critics argue that there is a quality decline associated with the transition from primary-care doctors to advanced practice practitioners, although most studies don't support that argument. Supporters claim that APPs provide a lower-cost option without a decline in care quality.
Advanced practice practitioners were more likely to overestimate the risk of UTIs, cardiac ischemia and breast cancer than residents and attending physicians, according to the study. Still, all types of primary-care practitioners tended to overestimate the risk based on tests and reported symptoms.
"It is an important area to consider with the shifts in workforce," Morgan said.
