The number of adverse events in hospitals may be higher than previously thought

Adverse events in hospitals may be ten times more prevalent than previously thought, according to a study in Health Affairs.

The study examined data for almost 800 patients, and compared adverse event reporting for voluntary reporting, the Agency for Healthcare Research and Quality system for detecting adverse events, and the Institute for Healthcare Improvement's Global Trigger Tool, and found notable differences. 

The study found that voluntary reporting detected only four patient problems, the AHRQ reporting tool picked up 35 adverse events, and the Global Trigger Tool noted 354 events, 10 times more than the AHRQ method detected.

The authors recommend further investigation into expanding the use of the Global Trigger Tool, with guidance from policymakers. 

(Sources: Health Affairs,, April, 2011; Reuters,, April 7, 2011; Kaiser Daily Health Policy Project,, April 7, 2011)