Patient Safety and Adverse Events

HCUP Statistical Brief 237

Improving patient safety and the quality of health care is a national priority in the United States. Patient Safety and Adverse Events, a statistical brief from the Healthcare Cost and Utilization Project, focuses on 14 of the 19 AHRQ Patient Safety Indicators (PSIs), as defined by technical specifications posted on the AHRQ Quality Indicator Web site. The 14 indicators represented in this statistical brief are risk adjusted for age, sex, major diagnostic categories, modified diagnosis related groups, and comorbidities. Some indicators are also adjusted for transfers of patients from other facilities or for severity of complications present on admission to the hospital.

These indicators provide a measure of potentially preventable complications of adult medical and surgical hospital care. The PSIs focus on adverse events during the hospital stay (such as pressure ulcers), complications associated with surgery (such as hemorrhage or hematomas, respiratory failure, or pulmonary embolism/deep vein thrombosis), and patient safety overall (a composite of the patient safety events). Rates vary by hospital and across time, with evidence demonstrating that the implementation of hospital quality improvement practices reduces avoidable harms to patients.


  • Across hospitals in 34 States, the overall number of patient safety and adverse events for the 13 selected AHRQ PSIs declined from 2011 to 2014, with one exception.
  • The hospital risk-adjusted rates per 1,000 discharges of all 13 PSIs decreased in 34 States from 2011 to 2014. Among the selected PSIs, average hospital rates for in-hospital falls with hip fracture decreased the most (73.9 percent).
  • The percentage of hospitals in 34 States with no patient safety and adverse events increased between 2011 and 2014 for each of the 13 risk-adjusted PSIs analyzed.
  • The percentage of hospitals with no catheter-related blood stream infections increased the most, from 52.3 percent in 2011 to 71.3 percent in 2014.
  • In 2014, more than 90 percent of hospitals in 34 States had average or better-than-average risk-adjusted patient safety and adverse event rates for 11 of the 13 PSIs analyzed.
  • Hospital improvements in patient safety and adverse events were noted from 2011 to 2014 in 34 States. There was a decrease in the percentage of hospitals classified as worse than average (from 9.5 to 6.7 percent) and an increase in the percentage of hospitals classified as better than average (from 3.4 to 5.5 percent).

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Page last reviewed March 2018
Page originally created March 2018
Internet Citation: Patient Safety and Adverse Events. Content last reviewed March 2018. Agency for Healthcare Research and Quality, Rockville, MD.