"To Err is Human: Building a Safer Health System," the original Institute of Medicine report in 1999, stated that between 44,000 and 98,000 deaths each year were caused by preventable medical errors.
That report was widely cited and spawned a number of studies and reviews claiming that anywhere from 250,000 to 440,000 preventable deaths occur in the United States every year.
I was critical of the 440,000 deaths paper as well as the most recent of these estimates—the one claiming 250,000 deaths due to medical errors per year.
It's not widely known or perhaps simply forgotten, but the 1999 Institute of Medicine report also came under fire. In 2000, two researchers from Dartmouth, Drs. Harold C. Sox Jr, and Steven Woloshin, published a critique called "How many deaths are due to medical error? Getting the number right."
In that paper, the authors pointed out that the IOM was correct about the number of adverse events per hospitalization (2.9-3.7%). However, the IOM's report was based on only two studies which used data from 1984 and 1992 and did not define preventable adverse events or medical errors.
Re-analyses of the two papers judged that 54-69.6% of deaths due to adverse events were preventable, figures that Sox and Woloshin said were subjective and not reliable because the re-analyses were performed by looking only at summaries of patient hospitalizations not the actual records.
As is the case with all subsequent preventable death studies, the IOM report relied on many estimates and extrapolations.
Sox and Woloshin concluded, "It is unfortunate that we do not have a credible estimate of the number of deaths due to medical errors." That statement remains true today.
If you think it's easy to tell a preventable complication from a non-preventable one, read this summary of a case from one of the papers cited in the IOM extrapolation.
A 39-year-old woman employed as an engineering and science technician had a laparoscopic cholecystectomy. Three days later, she developed fever and abdominal pain and was found to have a bile leak and possible infectious peritonitis requiring 4-day hospitalization for observation only.
Was this complication preventable or not?
Feel free to explain your answer in a comment.
In a few days, I will tell you what the reviewers decided.