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2004 National Healthcare Quality Report

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Chapter 3. Patient Safety

Importance and Measures

Morbidity and Mortality

  • A 1999 report by the Institute of Medicine, To Err Is Human, estimated that 44,000 to 98,000 Americans die each year as a result of medical errors, making it the eighth leading cause of death1.
  • A recent study reported that at least 32,000 Americans die in the hospital each year due to 18 types of medical injuries2.


  • The cost attributable to medical errors is as much as $29 billion annually in lost income, disability, and health care costs1.


Much progress has been made in recent years in raising awareness, developing event reporting systems, and developing national standards for data collection. However, data remain incomplete for a comprehensive national assessment of patient safety3. Nevertheless, several measures are available to provide insight into the level of patient safety in the United States. This section highlights NHQR patient safety measures in three areas:

  • Hospital-acquired (nosocomial) infections
  • Adverse events and postoperative complications of care
  • Inappropriate use of medications by the elderly

The measures reviewed are based on data from the CDC's National Nosocomial Infection Surveillance (NNIS) System4, AHRQ's Patient Safety Indicators applied to the HCUP Nationwide Inpatient Sample (NIS)5, CMS's Medicare Patient Safety Monitoring System (MPSMS)6, and AHRQ's Medical Expenditure Panel Survey (MEPS)7.


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