The Startling Truth About Doctors and Diagnostic Errors

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http://www.progress.org/2008/doctors.htmThe Startling Truth About Doctors and Diagnostic Errors Does an autopsy count as a second opinion? By Maggie Mahar and Niko KarvounisWhile diagnosis of disease is not an exact science, misdiagnosis almost always can be traced to how doctors think. In clinical specialties that rely on data gathering and synthesis rather than observation, error rates tend to run as high as 15%.Other medical errors, such as hospital-acquired infections, are more easily counted. For example, the average hospitalized patient experiences one medication error a day; the average ICU patient has 1.7 errors per day in their care. But the count on missed diagnoses is not clean.Doctor mistakes may not kill for hours [i.e., if a doctor misses myocardial infarction in a patient], days (missed meningitis) or even years (missed cancers).Consider a common, usually nonfatal disease. Appendicitis was missed in almost one fifth of patients. An appendectomy was performed on over one tenth of patients who did not suffer the disease.Want a second opinion? When over 100 surgeons were showed the insides of patients, they agreed only 18% of the time as to how many tissue areas were actually diseased.Are machines better? The one showing abnormal heartbeat was wrong for 35% of patients. The reviewing clinician caught the error three fourths of the time.Often the physician is too confident, as are many people. In academia -- another arena bottlenecked by government-granted privilege -- 94% of academics rate themselves in the top half of their profession. And only 1% of drivers rate their skills below that of the average driver.Researchers find an inverse relationship between confidence and skill. In one study, resident doctors often stayed wedded to an incorrect diagnosis even when a diagnostic decision support system suggested the correct diagnosis. In another, clinicians who were completely certain of the diagnosis before death were wrong 40% of the time.Physicians tend to ignore computerized decision-support systems, often in the form of guidelines, alerts, and reminders. The care they provided deviated from recommended best practices half of the time. The high rate of noncompliance with clinical guidelines relates to what it means to be a professional.The physician isn't willing or able to reflect on [his] own thinking processes and critically examine [his] assumptions, beliefs, and conclusions. In confirmation bias, people "anchor" on findings that support their initial assumptions. It's much easier to pull out the data that proves you right and pat yourself on the back than it is to look at the contradictory evidence and rethink your assumptions.What doctors need to do is to simultaneously make a decision -- and keep an open mind. Too often physicians narrow the diagnostic hypotheses too early in the process, so that the correct diagnosis is never seriously considered. Reliance on advanced hi-tech tests can encourage "premature closure."Sometimes a patient who isn't getting better simply leaves the doctor and finds someone else. Or the patient may be discharged from the hospital, relapse three months later, and go to a different ER. Or the patient gets better despite the wrong diagnosis. (It is surprising how often bodies heal themselves.) In each case, the doctor can assume that the diagnosis was right and that the treatment "worked."When treatment fails, autopsies are done in 10% of deaths; many hospitals do none. With imaging technologies such as CT scanning and ultrasound, an autopsy seems a waste of time and resources. Yet autopsies -- holding and looking at the diseased body -- turn up a major misdiagnosis in roughly 40% of all cases. Some autopsies showed doctors missed fatal TB and blood clots at least half the time and certain tumors over 40% and breast cancer over 20% of the time. The rate at which misdiagnosis is detected in autopsy studies has not improved since at least 1938.Yet autopsy studies only provide the error rate in patients who die. The error rate is much lower in patients who survived. Still, there's always room for improvement.Autopsy literally means "to see for oneself". Throughout much of the 20th century, doctors diligently obtained autopsies in the majority of all deaths. And the results were regularly discussed at mortality and morbidity conferences, where doctors became Monday-morning quarterbacks, discussing what they could have done differently.Sometimes it turns out that doctors had missed a clue along the way or made a genuine mistake. Sometimes doctors turn out wrong despite doing everything right. One cannot expect doctors to learn from their mistakes unless they have -- and accept -- feedback. Also see:Iatrogenic Death http://www.progress.org/archive/fold107.htmRacketeering: The "Doctor Prevention" Subsidy http://www.progress.org/archive/tcs23.htmA Stand for Scientific Independence http://www.progress.org/archive/medic03.htm =====In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.