Blog | Monday, September 23, 2013

QD: News Every Day--Up to 440,000 deaths due to preventable adverse events

There could be 440,000 deaths annually due to preventable adverse events, and that’s a conservative estimate, a researcher concluded.

The study cited barriers to preventing adverse events, including increased volume of medical knowledge, lagging implementation of electronic medical records and America’s “patchwork” system of care. “It should be no surprise that (preventable adverse events) PAEs that harm patients are frighteningly common in this highly technical, rapidly changing, and poorly integrated industry. The picture is further complicated by a lack of transparency and limited accountability for errors that harm patients,” the author wrote.

An Institute of Medicine report from 1984 estimated 98,000 deaths annually from medical errors. To derive a more modern estimate, the researcher reviewed the literature and found 4 studies published from 2008 to 2011 that used the Global Trigger Tool to flag specific evidence in medical records, such as medication stop orders or abnormal laboratory results, which point to an adverse event that may have harmed a patient.

Four studies were found; each used similar methods to flag, confirm and classify adverse events by level of harm. All studies used a 2-tier approach that had nurses or pharmacists screen medical records to flag suspect events, and then had physicians determine if an adverse event had occurred and how serious it was.

Because the 4 study populations were so different, the researcher used a weighted average. In one study there were more than 4,500 records reviewed and 38 deaths associated with adverse events (0.89%). There were an estimated 34.4 million hospital discharges in 2007, and the average percentage of preventable adverse events among all adverse events in the three other studies was an average of 69%. The four studies combined tallied 34.4 million × 0.69 × 0.0089 = 210,000 preventable adverse events per year.

However, the researcher noted, the search capability of the Global Trigger Tool is limited, as is the incompleteness of medical records on which it depends. Some events may go unreported by physicians. The researchers applied a minimum estimate of a 2-fold increase to compensate, and then included an estimate of 40,000 undetected diagnostic errors (210,000 × 2) + 20,000 to calculate that there might be 440,000 premature deaths associated with preventable harm. And, serious harm seems to be 10- to 20-fold more common than lethal harm.

The researcher wrote, “In a sense, it does not matter whether the deaths of 100,000, 200,000 or 400,000 Americans each year are associated with PAEs in hospitals. Any of the estimates demands assertive action on the part of providers, legislators, and people who will one day become patients.”