For nearly 50 years, pediatrician William Sharrar has been evaluating how his young patients are changing — mentally and physically — as they get older.

This year, his bosses at Cooper University Health Care told Sharrar, 76, that he would have to face similar scrutiny or lose his job.

Cooper is among the growing number of hospitals that are reevaluating doctors simply because they are old. Their age puts them at higher risk for physical and cognitive changes that could imperil patients.

So, in June, Sharrar underwent hours of testing at Rowan University's Institute for Successful Aging to measure whether he was strong enough to do his job — could he lift a 20-pound child? — and whether his brain was still agile enough to make good decisions.  He passed.

Some of his colleagues were upset and anxious about this new hurdle, but Sharrar said he accepted it without complaint. "We all know that with age, there does come cognitive decline," he said. "It's just a safety issue."

Frank Stockdale, an 81-year-old breast cancer specialist at Stanford University Medical Center in California, disagrees — vehemently.  He and some colleagues over 75 fought off plans to require cognitive testing by arguing, correctly, that there is no scientific evidence correlating such test results with physician performance. They have, however, grudgingly accepted physical testing and peer review.

"This is clearly age discrimination," said Stockdale, who thinks doctors of all ages should be tested for possible impairment.

Like many health system leaders, Ann Weinacker, vice chair of medicine for quality implementation at Stanford Health, doesn't think that's practical or sensible.  "Typically in medicine, you screen for things that are likely to be an issue," she said.

As more doctors choose to work past the traditional retirement age, health systems are navigating a complex set of issues that revolve around what may sometimes be  competing interests: keeping valued "late-career" employees happy and keeping patients safe.  Most older doctors do good work and many choose to do less challenging work as a concession to age,  experts said. But systems are testing how best to screen for the few who are slipping and don't know it.  This region's two largest health systems — Penn Medicine and Jefferson Health — are embarking on screening programs.

Nationally, the number of active physicians over age 65 quadrupled from 50,993 in 1975 to 241,641 in 2013, according to the American Medical Association. The Federation of State Medical Boards found that the number of actively licensed doctors age 70 and up grew from 75,627 in 2010 to 94,969 last year.

Not just a job, an identity

Doctors may be especially inclined to keep practicing because their work is so rewarding, said Peter Quinn, an oral and maxillofacial surgeon who heads Penn's 2,100-member physician practice.  He is 69 and will be among the first to take the cognitive screening test that Penn is developing.  "It's not just a job with a doctor," he said. "It's an identity."

While airline pilots must quit by 65, mandatory retirement at a certain age is rare in most other fields, in part because age discrimination is illegal. There is also huge variability in how people over 60 age, much more than at earlier stages of life. "We do all know 80-year-olds who can do vigorous sports and other 80-year-olds who can't get out of their chair," said Mark Katlic, a thoracic surgeon who runs an evaluation program for aging surgeons at Sinai Hospital in Baltimore.

What's more, experts predict a physician shortage that would be worse in rural areas if older doctors quit working.

Supporters of assessing physicians say they are not trying to push doctors out. In fact, appraisals might help hospitals keep older doctors working longer by adjusting shifts and tasks to best suit their abilities, and prevent career-ending mistakes.

Pittsburgh's UPMC Health System was among the first to begin evaluating older doctors.  Three years ago, it started testing physicians age 70 and up on cognitive skills, physical health, and job performance. Donald Yealy, senior medical director of the health services division, said he's not aware of anyone who was forced to resign, but some doctors have changed the kinds of work they take on.  "The process has helped the physicians understand, 'Maybe it's time to change my practice,' " Yealy said.

Doctors, experts said, are not particularly good at recognizing their own cognitive problems, or even medical ones.  One article in Clinical Orthopaedics and Related Research described an elderly surgeon who could not find his own office after a day of surgery.  Katlic collected anecdotes for another article in Annals of Surgery.  He was told of a surgeon who fell asleep during surgery and another who operated on the wrong side of a patient's brain.  Residents felt forced to intervene when a doctor made poor decisions during surgery.

Most of the time, Katlic said, it's hard to prove faltering doctors actually hurt patients, but coworkers have reason to fear that some could. Evaluation policies are meant primarily to prevent that. But they also can ease those awkward interventions when someone has to tell a respected mentor or hospital rainmaker it is time to go.

In 2015, the American Medical Association called for guidelines to evaluate aging doctors, although it did not specify what they should be.  It also said doctors have a "professional duty" to self-assess.  The American College of Surgeons last year said surgeons should voluntarily undergo testing by their personal physicians and  disclose any problems to their employers.

A review published this summer in JAMA Surgery called for requiring evaluations of older doctors.  The lead author, E. Patchen Dellinger, a University of Washington surgeon who is 73, had long been interested in the topic because he had seen older doctors develop problems.  After he turned 70, he had himself tested.

"I vowed at least 20 years ago, if not earlier … that I would stop operating before one of my colleagues called me aside and said we ought to have a talk," he said.

‘The ones that get into trouble’

Many medical leaders are concerned that outsiders will impose rules if insiders don't.

Jonathan Burroughs, a New Hampshire-based physician and health-care consultant, estimates that 5 percent to 10 percent of hospitals now have policies on aging or "late-career" practitioners.  Some, like the University of Virginia Health System, also encompass nurse-practitioners and physician assistants.   Burroughs thinks top managers should be included.  "I cannot tell you the number of times I've seen failing CEOs who drive an organization into the ground," he said.

While doctors perform better than the general public on tests of cognitive function throughout their lives, their scores, on average, still decline with age, a study found.  Performance tends to slip with age on measures like processing speed, retaining information while solving problems, and disregarding irrelevant information.  That could increase the risk for problems in chaotic situations like an unusual medical emergency.  On the positive side, the report by the AMA Council on Medical Education pointed out that some important attributes may improve with age:  wisdom, resilience, compassion, and tolerance for stress.

A growing body of research on physician performance throughout the lifespan shows mixed results, but Katlic has found multiple studies showing worse outcomes for older surgeons performing different types of procedures.  In two large studies, though, he said, some of the differences could be attributed to older physicians seeing fewer patients, which itself is often associated with worse results. The AMA Council cited several studies that found that older doctors didn't do as well as younger physicians on knowledge tests or in the way they examined patients or kept records.

Yet few physicians who have had the evaluations have had to quit or modify their work significantly.  Only a "tiny minority" differ from younger colleagues on more than one area of testing, Katlic said, adding, "The trouble is, those are the ones that can get into trouble."

‘A valuable program’

Katlic, 66, said his extensive work with elderly patients made him wonder about geriatric doctors. That led to his two-day evaluation program, one of the country's most rigorous.

The Aging Surgeon Program, which is available to doctors from anywhere,  involves extensive cognitive and physical testing as well as evaluation of balance, reaction time, and fine motor skills.

The price tag is hefty — $17,000 — and so far just two surgeons have completed the testing, though more than 100 have sought information.  The program reports results, but employers decide what to do about them. Some surgeons quit when the program was recommended to them.

Herb Dardik, an 82-year-old physician at Englewood Hospital and Medical Center in Bergen County, N.J., was furious when a supervisor first suggested that he go.  A severe kidney problem forced him to miss work in late 2015.  He didn't feel up to doing a procedure on a patient's carotid artery when he first got back to work, so he asked a colleague to do it. Dardik promised the patient he'd be in the room.  He was, but he fell asleep.

The next day, the chief of anesthesia and the chief medical officer visited him, he said. He threw them out of his office. A week later, they suggested Katlic's program and Dardik said, "Absolutely not."   They tried again a week later. That time Dardik softened. "If I were on an airplane," he thought, "and an elderly pilot comes walking in there, I would want to be sure he was OK."

He took the test and "passed with flying colors," he said.  He became a fan of testing.  "I came back convinced that it is a valuable program. It was a little more intense than it needed to be," he said.  "This is something that all places should do."

Since then, his back has worsened. It's too painful to stand in the operating room.  Dardik is still working full time, but as a teacher and researcher.  His nights and weekends are freer now, so he gets to read some nonmedical books and practice his piano.  The best thing is that his day starts two hours later — at 9 a.m. — so he can swim laps in the morning.  He loves it.

How some health systems are screening older doctors

Penn Medicine

Penn decided last year to look for a better way to handle the problems it encounters with a handful of its older doctors each year, said Peter Quinn, a surgeon who heads Penn's physician practice.

Maybe a pathologist was no longer reading slides as accurately as in the past or a surgeon was working too slowly.  The system had ways to evaluate those doctors that seemed to work, but Quinn and other leaders wanted a "fair and consistent" policy that would treat everybody the same.

Penn's solution: a cognitive screening test for all doctors ages 70 and up. As many as 110 of Penn Medicine's 2,100 doctors will be affected.  A dementia expert is developing a test to flag early signs of cognitive decline.  It will be tried first on 18 clinical department chairs  and 14 members of the medical board in about three months.  Quinn, who turns 70 in 10 months, expects to be among the first doctors to take it for real next year.

Jefferson Health
Prominent orthopedic surgeon Richard Rothman, founder of the Rothman Institute,  is vice chair of the Jefferson Health board and a longtime supporter of evaluating older doctors, particularly surgeons.  Now 80, he still does surgery, but has his vision checked regularly and recently asked a senior partner to monitor the quality of his work for a day.  He did fine.  He says he's told others to speak up if they see the quality of his surgery slip.  "I always told my partners, 'The day you think I'm off my game, I want you to come in and tell me, and you'll be doing me the biggest favor in the world,' " he said.

Routine testing beats having to tell a colleague to retire because of poor work, he said.  Rothman once discovered that a fellow surgeon was legally blind. Such encounters are, he said, "a very unpleasant business."

Rothman has been lobbying for Jefferson to develop an evaluation policy for older doctors. The health system's CEO, Stephen Klasko, is on his side. But Klasko thinks the evaluations should start around age 40 and be given again at 50 and 60, then every five years. He's 63 and an obstetrician-gynecologist.  "The last time anybody checked my technical competence was about 32 years ago," he said.  He expects Jefferson to have a policy in place in a year or so.

Too often, a doctor isn't assessed until he "has a really bad case."  That, he said, is like telling a pilot, "After you've crashed, then we'll check you."

Cooper University Health Care
Cooper has more than 20 doctors who are 72 or older, the ages covered by the late-career policy it approved in March 2015. Also, 57 of the health system's 650 physicians are 65 to 72.  Anthony Mazzarelli, Cooper's senior executive vice president and chief physician executive, said that requiring physical and cognitive testing supports both patient safety and long physician careers.  So far, only one doctor has retired rather than go through it and another is  having a more thorough evaluation after issues arose during the screening.

Richard Jermyn, chair of physical medicine and rehabilitation for Rowan School of Osteopathic Medicine, oversees the physical testing, which is tailored to each doctor's job.

A surgeon, he said, needs to be more physically fit than most doctors. The program has found doctors with uncontrolled diabetes and hypertension.

David Libon, a clinical neuropsychologist with Rowan's Institute for Successful Aging,  is looking for subtle signs of dementia when he evaluates Cooper doctors.  Some may do well with extremely specialized, long-practiced work.  He wants to know whether they can handle situations "clearly not within their normal scope of activities."  The tests measure capacity to learn and retain new information, executive control, processing speed, and language and visual-spatial skills

"In large part, I've not found serious problems in this group," he said.

Since 2008,Virtua has required all physicians to have a physical and cognitive medical exam by their own primary-care doctors when they turn 70 and every two years after that.  There is also a peer evaluation.

Main Line Health
Main Line Health assesses doctors on a case-by-case basis, sending some to the Foundation of the Pennsylvania Medical Society's LifeGuard assessment program, which tests about 25 physicians of various ages from throughout the country each year, usually because of a problem. One 70-year-old doctor was sleepy after being on call for 24 hours straight, said Marcia Lammando, the program director. He stopped doing that and was fine.  The program found another doctor had a brain tumor.

Temple Health
A spokeswoman said that Temple Health is developing a policy but that it would be premature to discuss it.