A new study from Johns Hopkins appears this week in the British Medical Journal that shows that diagnostic errors are the number 1 cause of malpractice lawsuits and the number one cause of payouts to patients and their lawyers. What it does not say in the text, but it states in the tables, is that bad surgical results are not far behind. The percentages for payouts for diagnostic and surgical mishaps are 29 and 24%, respectively. The investigators who wrote the study used a long standing American repository of doctors' misadventures, the National Practitioner Data Bank which contains information on U.S. doctors' malpractice suits.
The importance of diagnostic errors in the overall picture is emphasized by the 41% mortality rate associated with such blunders. The comparable rate with surgical errors is only 14%. The prominence of diagnostic errors was first shown in studies from Harvard 22 years ago using hospital charts and not the results of law suits. In 1133 hospitalized patients harmed by medical management, 265 or 23% were the result of diagnostic error, whereas errors of technique, a category largely comparable but not identical to surgical errors, the numbers were 559 or 49%. A 2010 study, also derived from hospital charts, from Harvard and Stanford, showed that the percentage of errors that were from procedures, again comparable to technical or surgical errors, was 32% while diagnostic evaluation errors were only 1%.
The differences in the numbers among the three studies are somehow related to the way they were obtained. It may be that diagnostic errors are more easy to discern by patients and so they are more likely to sue or that it is easier to win a legal case against a doctor for one type of error than the other. Differences like these are not uncommon among published medical reports and although it is distressing to lay people to see such variances, doctors are used to them. What can be distilled from all of this is that diagnostic and technical (surgical, procedural) errors are common and dangerous to patients.
The key concern from the point of view of prevention is that both diagnostic and technical errors are highly resistant to prevention by the method used by the medical profession for the past 12 years, the systems approach. A conversation with one of the authors of To Err is Human, the document from the Institute of Medicine which started the whole medical error hue and cry in 2000 and pushed the systems approach hard, was quite revealing. The authors of To Err is Human felt in 2000 that the systems method, the one that made commercial aviation safer, would reduce medical errors by 50% in 5 years. That never happened and probably never will. The co-author of the report had to concede that both surgical errors and diagnostic errors could not be prevented by systems means. This means that the whole line of attack used to making hospitals and doctors' offices safer needs to be overhauled. Next time: what the newer medical literature says on how to prevent diagnostic errors.