Here's what you need to know to be sure you end up with the right answer

After returning from a business trip to Malaysia six years ago, Joe Cherry began suffering from a flu-like illness, then woke up one day with a crushing pain in his arm and chest. Once a heart attack had been ruled out, the emergency-room doctor diagnosed carpal tunnel syndrome, a painful wrist condition. "I used to work for a company [that] made devices for carpal tunnel surgery," recalls Cherry, 62, "and I knew this wasn't what I had." He saw three more physicians over four weeks before finally getting answers.

Doctors are stumped by symptoms all the time, and by prescribing the wrong medication, they often worsen the problem or even create a new one. Worse, misdiagnoses lead to an astounding 40,000 to 80,000 hospital deaths every year, according to a March paper published in the Journal of the American Medical Association -- plus an uncounted number due to mistakes in the doctor's office. In fact, some 5 percent of autopsies find a condition missed by doctors that, if treated, might have saved the patient's life.

Certainly, some diagnoses -- like strep throat -- can be made in minutes. But the head-scratchers require a doctor with the patience to probe, plus a sharp set of mental skills that include a willingness to question his or her own logic -- which can be tough to do in a 15-minute office visit. "Doctors are like detectives," says Jerome Groopman, professor of medicine at Harvard University and author of the bestselling How Doctors Think. "They sometimes encounter red herrings and make connections that are incorrect." While tumors and inherited diseases have become easier to pinpoint, thanks to genetic testing and ultrarevealing imaging, some experts worry that doctors too often rely on technology as a replacement for old-fashioned reasoning and history taking.

Part of the blame can be placed on sagging reimbursements and increased job pressures. For doctors at top academic hospitals, "the emphasis is on research, new discoveries, grant dollars," says John Flynn, clinical director of internal medicine at Johns Hopkins Hospital. "It's tough to do all the clinical care you need to develop your expertise and [also] survive in an academic institution." Doctors in private practice, paid by the test and procedure rather than by the minute, are finding that in-depth conversations are a luxury they can no longer afford.

New York City internist Tom Bolte decided 14 years ago to stop taking health insurance when his reimbursements for office visits fell from $45 per patient to $22.50 -- forcing him to nearly double his patient load. Now, specializing in tough-to-crack diagnostic cases, he typically sees only three or four patients a day and spends at least two hours on an initial visit for a fee of $250 to $450. Plenty of people with unexplained, unremitting pain are willing to travel across the country to see him and to fill out a 32-page questionnaire detailing symptoms, family history, sensitivity to cleaning products -- even whether they have an attached garage, which may trap noxious fumes. One recent success: A woman discovered after multiple misdiagnoses that her headaches, hives, and fatigue were linked to a faulty gas pipe in her apartment.

While treatment mistakes like dispensing an overdose of medication are often caused by technical glitches, misdiagnoses are usually the result of flaws in a physician's thinking, says Groopman. Doctors, like the rest of us, sometimes make mistakes because they take "cognitive shortcuts," or jump to conclusions -- an overweight man clutching his chest must be having a heart attack, for example -- and then can't budge even when contradictory evidence emerges. Blame the 18-second rule. "That's the average time it takes for a doctor to interrupt you as you're describing your symptoms," says Groopman. "By that point, he has in mind what the answer is, and he's probably right about 80 percent of the time."

It's not that a doctor lacks sufficient clinical knowledge -- one study suggests that only 4 percent of misdiagnoses are caused by that -- but rather is tripped up by his or her biases. "When I supervise the training of medical students, I often tell them to ask themselves, if you're wrong in your diagnosis, what is the thing that you might have been wrong about?" says Robert Wachter, chief of hospital medicine at the University of California, San Francisco Medical Center. "I'm trying to get their minds to work differently, to question their own thinking." Bolte recently saw a man with severe abdominal pain who had been diagnosed with an intestinal infection and put on antibiotics. "His previous doctor never asked him about his diet," says Bolte, who quickly discovered the man, though deceptively thin, "survived on candy, ice cream, and McDonald's." The cure: whole grains and produce.

-- After heading back to his job managing a medical device firm in Murray Hill, N.J., Cherry went to see another doctor -- and then a third -- for relief from a new onslaught of scary symptoms: breathing problems, blocked sinuses, extreme weakness, rapid weight loss, and numbness in his extremities. One doctor "just gave me a nasal spray," he says, and the other suspected some exotic foreign disease when a blood test showed a spike in white blood cells. He told Cherry to see an infectious disease specialist immediately.

-- Besides relying on first impressions, physicians often put too much stock in their past experience -- overdiagnosing tumors, say, because they missed one once. Or, instead of trusting their instincts, they defer to a more experienced colleague or to the adage drummed into them as medical students: "When you hear hoofbeats, think horses, not zebras." Result: They miss the zebra.

Dizziness, for example, frequently is explained by inner ear fluid, migraines, or a medication reaction. But about 5 percent of the time, it indicates a stroke, and these patients may have no other telltale signs like numbness or weakness on one side of the body, says Johns Hopkins neurologist David Newman-Toker, who has studied misdiagnoses in hospitals. A spinning room and pounding headache sent Margaret Powell, 59, to Hopkins last August; with those vague symptoms, Powell had about a 35 percent chance of being misdiagnosed, contends Newman-Toker. Fortunately for Powell, the emergency room doctor asked her the right questions: Was this her first dizzy spell? (Yes.) Lasted for more than two minutes? (Yes.) Not brought on by anything in particular? (Yes.) An MRI confirmed a stroke, and Powell was immediately put on blood-thinner drugs.

Physicians who pride themselves on their diagnostic skills say that, like Olympic athletes, they train constantly. Gurpreet Dhaliwal, an internist at the San Francisco Veterans Affairs Medical Center, hones his skills by devouring medical journal case reports and reviewing patient charts from other departments. While examining a patient, he says, he practices "meta cognition," or thinking about what he's thinking, to look for slip-ups. Finally, he taps into his patients' electronic records days or weeks after he first examined them to check that he made the right call.

-- Cherry managed to get an appointment with John Mann, a leading infectious disease specialist at Johns Hopkins, who noticed that several things didn't jibe with an infection. For one thing, most infections don't linger so long without putting the patient in the hospital. "For someone with so many things wrong with him, he wasn't feverish and didn't look acutely ill," Mann says. He began to suspect an autoimmune disease, a condition in which Cherry's body was attacking its own tissues.

-- Some experts believe the solution to reducing diagnostic errors lies in decision-support software like Isabel, which allows doctors to input a medical history and often disparate, puzzling symptoms and get a list of possible causes. The biggest drawback: It often lists too many possibilities because of common symptoms; overlap between a cold and bubonic plague, for example, is 95 percent. But such programs could prove extremely useful within the next few years, Wachter thinks, if a patient's own electronic medical record could be incorporated into the mix.

Newman-Toker is currently testing a computerized questionnaire that asks patients experiencing dizziness to tap in their symptoms while waiting to see an ER physician. The program, which assesses the likelihood of stroke, helps ER docs decide who should be admitted for a full diagnostic work-up. "Some doctors ask why they can't just do an MRI on everyone experiencing dizziness," says Newman-Toker. "But that's not fiscally responsible." He's tested the program on 1,000 patients so far and expects to publish results soon.

-- Mann listened for nearly an hour as Cherry described his work, family life, and overseas trips -- and a car accident years earlier that left him with chronic asthma. The asthma, along with the extremely elevated white blood cell count, pointed Mann toward a rare autoimmune disease called Churg-Strauss syndrome, which often begins with asthma and then inflames blood vessels, causing pain in the extremities. His suspicions were confirmed with a tissue biopsy, and Cherry was immediately put on powerful steroids and immune-suppressing drugs. He was fortunate. "I was told that I wouldn't be alive today if I hadn't gotten there that week," Cherry says. "I would never have met any of my five grandchildren."

 

 

(c) 2009 U.S. News & World Report