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2006 National Healthcare Quality Report

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Chapter 3. Patient Safety

The Institute of Medicine defined patient safety in its 1999 report, To Err Is Human, as freedom from accidental injury due to medical care or medical errors.1

Importance and Measures

Mortality
Number of Americans that die each year from medical errors (1999 estimate) 44,000-98,0001
Number of Americans that die in the hospital each year due to 18 types of medical injuries (2000 estimate) at least 32,0002
Cost
Cost attributable to medical errors (in lost income, disability, and health care costs) (1999 estimate) $17 billion-$29 billion1

Measures

Much progress has been made in recent years in raising awareness, developing event reporting systems, and developing national standards for data collection. Data remain incomplete for a comprehensive national assessment of patient safety.3 Nevertheless, several measures are available to provide insight into the level of patient safety in the United States.

This year's selection of patient safety core report measures has changed from previous years. Some measures were removed from the set due to a discontinuation of the measure, a lack of new data, or concerns about data quality. Other measures were added that cover new and important aspects of patient safety. This year's chapter highlights six core measures relating to postoperative complications, other complications of hospital care, and complications of medications:

  • Postoperative care composite: pneumonia, urinary tract infection, and/or venous thromboembolic event
  • Appropriate timing of antibiotics among surgical patients
  • Adverse events associated with central venous catheters
  • Deaths following complications of care
  • Adverse drug events in the hospital
  • Inappropriate medication use among the elderly

Findings

Postoperative Complications

Adverse health events can occur during episodes of care, especially during and right after surgery. Although some of the events may be related to a patient's underlying condition, many of them can be avoided if adequate care is provided.

Postoperative care composite: pneumonia, urinary tract infection, or venous thromboembolic event. Complications after surgery may include but are not limited to pneumonia, bladder infection, and blood clots in the legs.

Figure 3.1. Surgical patients with postoperative pneumonia, urinary tract infection, and venous thromboembolic event and composite, 2003 and 2004

Figure 3.1. Surgical patients with postoperative pneumonia, urinary tract infection, and venous thromboembolic event and composite, 2003 and 2004

Source: Centers for Medicare & Medicaid Services, Medicare Patient Safety Monitoring System, 2003-2004.

Denominator: Hospitalized Medicare patients having surgery.

  • From 2003 to 2004, the percentage of surgical patients with postoperative pneumonia, urinary tract infection, or venous thromboembolic event did not change significantly (Figure 3.1).

Appropriate timing of antibiotics among surgical patients. Infections acquired during hospital care (nosocomial infections) are one of the most serious safety concerns. A common hospital-acquired infection is a wound infection following surgery. Hospitals can reduce the risk of wound infection after surgery by making sure patients get the right antibiotics at the right time on the day of their surgery. Research shows that surgery patients who get antibiotics within the hour before their operation are less likely to get wound infections; getting an antibiotic earlier, or after surgery begins, is not as effective. However, taking these antibiotics for more than 24 hours after routine surgery is usually not necessary and can increase the risk of side effects such as stomach aches, serious types of diarrhea, and antibiotic resistance. Among adult Medicare patients having surgery, the NHQR tracks receipt of antibiotics within 1 hour prior to surgical incision, discontinuation of antibiotics within 24 hours after end of surgery, and a composite of these two measures.

Figure 3.2. Appropriate timing of antibiotics received by adult Medicare patients having surgery, overall composite and two components, 2004

Figure 3.2. Appropriate timing of antibiotics received by adult Medicare patients having surgery, overall composite and two components, 2004

Source: Medicare Quality Improvement Organization Program, 2004.

Denominator: Hospitalized Medicare patients having surgery.

  • In 2004, 66.3% of adult Medicare patients having surgery received antibiotics within 1 hour of surgery, and 48.8% had their antibiotics stopped within 24 hours of surgery. Overall timing of antibiotics was appropriate 57.7% of the time (Figure 3.2).

Figure 3.3. Appropriate timing of antibiotics received by adult Medicare patients having surgery, by State, 2004

Figure 3.3. Appropriate timing of antibiotics received by adult Medicare patients having surgery, by State, 2004

Source: Medicare Quality Improvement Organization Program, 2004.

Key: Above average = appropriate timing of prophylactic antibiotics is significantly above the all-States average in 2004. Below average = appropriate timing of prophylactic antibiotics is significantly below the all-States average in 2004.

Denominator: Hospitalized Medicare patients having surgery.

Note: “All-States average” is the average of all responding States (52 in this case, including the District of Columbia and Puerto Rico), which is a separate figure from the national average.

  • Variation was seen among States in the overall timing of prophylactic antibiotics. In 2004, the all-States average was 57.7% and ranged from 39.6% to 71.3%.
  • Seventeen Statesi were significantly above the all-States average in 2004 (Figure 3.3), with a combined average rate of 66.7%.
  • Thirteen Statesii were significantly below the all-States average in 2004, with a combined average rate of 48.5%.

i The States were Montana, North Dakota, South Dakota, Nebraska, Oklahoma, Minnesota, Iowa, Missouri, Wisconsin, South Carolina, West Virginia, Maryland, Delaware, District of Columbia, New Jersey, Rhode Island, and Maine.
ii The States were California, Nevada, Wyoming, Arizona, Texas, Louisiana, Mississippi, Indiana, Ohio, Kentucky, Vermont, New Hampshire, and Puerto Rico.


Other Complications of Hospital Care

Besides surgery, other types of care delivered in hospitals can place patients at risk for injury or death.

Adverse events associated with central venous catheters. Patients who require a central venous catheter to be inserted into the great vessels of the heart tend to be severely ill. However, the procedure itself can result in infections and other complications.

Figure 3.4. Central venous catheter placements with bloodstream infection or associated mechanical adverse events and composite, 2003 and 2004

Figure 3.4. Central venous catheter placements with bloodstream infection or associated mechanical adverse events and composite, 2003 and 2004

Source: Centers for Medicare & Medicaid Services, Medicare Patient Safety Monitoring System, 2003-2004.

Denominator: Hospitalized Medicare patients with central venous catheter placement.

  • From 2003 to 2004, the percentage of central venous catheter placements with associated complications did not change significantly (Figure 3.4) for bloodstream infections, mechanical adverse events, or the composite of both measures.

Deaths following complications of care. Many complications that arise during hospital stays cannot be prevented. However, rapid identification and aggressive treatment of complications may prevent these complications from leading to death. This indicator, also called “failure to rescue,” tracks deaths among patients whose hospitalizations are complicated by pneumonia, thromboembolic event, sepsis, acute renal failure, gastrointestinal bleeding or acute ulcer, shock, or cardiac arrest.

Figure 3.5. Deaths per 1,000 patients following complications of care, 1994-2003

Figure 3.5. Deaths per 1,000 patients following complications of care, 1994-2003

Source: Healthcare Cost and Utilization Project, Nationwide Inpatient Sample, 1994-2003.

Denominator: Patients less than 75 years old from U.S. community hospitals whose hospitalizations are complicated by pneumonia, thromboembolic event, sepsis, acute renal failure, gastrointestinal bleeding or acute ulcer, shock, or cardiac arrest.

Note: Rates are adjusted for age, sex, diagnosis-related groups, and comorbidities.

  • From 1994 to 2003, the rate of deaths following complications of care declined from 155.4 to 129.7 per 1,000 patients (Figure 3.5).

Complications of Medications

Complications of medication are common safety problems. Some, but not all, adverse drug events may be related to misuse of medication. However, prescribing medications that are inappropriate for a specific population may increase the risk of adverse drug events.

Adverse drug events in the hospital. Some medications used in hospitals can cause serious complications. The Medicare Patient Safety Monitoring System tracks a number of adverse drug events including serious bleeding associated with intravenous heparin, low molecular weight heparin, or warfarin and hypoglycemia associated with insulin or oral hypoglycemics.

Figure 3.6. Medicare patients with adverse drug events, 2004

Figure 3.6. Medicare patients with adverse drug events, 2004

Source: Centers for Medicare & Medicaid Services, Medicare Patient Safety Monitoring System, 2004.

Denominator: Hospitalized Medicare patients receiving specified medication.

  • In 2004, adverse drug events in the hospital related to some frequently used medications were relatively common, ranging from 8.8% of Medicare patients who received warfarin to 14.6% of Medicare patients who received intravenous heparin (Figure 3.6).

Inappropriate medication use among the elderly. Some drugs are considered potentially harmful for elderly patients but nevertheless were prescribed to them.iii, 4

Figure 3.7. Inappropriate medication use by the elderly, 1996-2003

Figure 3.7. Inappropriate medication use by the elderly, 1996-2003

Source: Medical Expenditure Panel Survey, 1996-2003.

Reference population: Civilian noninstitutionalized population age 65 and over.

  • From 1996 to 2003, the percentage of elderly Americans who reported using at least one inappropriate drug decreased from 21.3% to 18.7 % (Figure 3.7).
  • The use of drugs that should always be avoided remained relatively stable over the 1996-2003 time period at about 3%.

iii Drugs that should always be avoided for elderly patients include barbiturates, flurazepam, meprobamate, chlorpropamide, meperidine, pentazocine, trimethobenzamide, belladonna alkaloids, dicyclomine, hyoscyamine, and propantheline. Drugs that should often be avoided for elderly patients include carisoprodol, chlorzoxazone, cyclobenzaprine, metaxalone, methocarbamol, amitriptyline, chlordiazepoxide, diazepam, doxepin, indomethacin, dipyridamole, ticlopidine, methyldopa, reserpine, disopyramide, oxybutynin, chlorpheniramine, cyproheptadine, diphenhydramine, hydroxyzine, promethazine, and propoxyphene.


References

1. Institute of Medicine. To err is human: building a safer health system. Washington, DC: National Academies Press; 1999.

2. Zhan C, Miller MR. Excess length of stay, charges, and mortality attributable to medical injuries during hospitalization. JAMA 2003 Oct 8;290(14):1868-74.

3. Institute of Medicine. Patient safety: achieving a new standard of care. Washington, DC: National Academies Press; 2004.

4. Zhan C, Sangl J, Bierman AS, et al. Potentially inappropriate medication use in the community-dwelling elderly: findings from the 1996 Medical Expenditure Panel Survey. JAMA 2001 Dec 12;286(22):2823-9.

 

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