Study says 12 million in U.S. misdiagnosed every year
New research suggests that at least one in 20 adults in the U.S., or 12 million people a year, may be misdiagnosed when they see their doctor. Researchers from the Houston Veteran Affairs Center for Innovations in Quality, Effectiveness and Safety estimated that about half of these diagnosis errors could lead to serious harm, such as when doctors fail to follow up on “red flags” for cancer in patients who ultimately are diagnosed with the condition.
The researchers used information from a sample of doctors' clinic visits (people who were not hospitalized), and reviewed hundreds of medical records to determine whether patients were misdiagnosed. The researchers also reviewed information from a sample of colon cancer and lung cancer patients, and looked for cases in which doctors did not follow up on "red flags" for these conditions, such as a positive colon cancer screening test, or an abnormal chest X-ray.
The researchers determined the error rates from these results compared to the larger U.S. population, taking into consideration that about 80 percent of adults visit the doctor each year. They concluded that, overall, about 5 percent of adults who visit the doctor are misdiagnosed every year. The researchers pointed out that the study likely did not capture all types of diagnosis errors so the rate could be higher. While the misdiagnosis rates for lung and colon cancer were considerably lower, the researchers noted that those errors were among the most harmful and costly ones.