5. How Do We Measure Our Pressure Ulcer Rates and Practices?

Preventing Pressure Ulcers in Hospitals: A Toolkit for Improving Quality of Care

Image shows seven interconnected puzzle pieces labeled Assess Readiness, Manage Change, Implement Practices, Best Practices, Measure, Sustain, and Tools. The piece labeled Measure is highlighted in blue.

A basic principle of quality measurement is: If you can't measure it, you can't improve it. Therefore, pressure ulcer performance must be counted and tracked as one component of a quality improvement program. By tracking performance, you will know whether care is improving, staying the same, or worsening in response to efforts to change practice. Moreover, continued monitoring will be key to understanding where you are starting and to sustaining your improvement gains.

During the course of your pressure ulcer prevention improvement effort and on an ongoing basis, you should regularly assess your pressure ulcer rates and practices. We recommend that you regularly monitor:

  1. An outcome (preferably pressure ulcer incidence or prevalence rates).
  2. At least one or two care processes (e.g., skin assessment).
  3. Key aspects of the infrastructure to support best care practices (e.g., clear lines of responsibility for overseeing accuracy of skin assessments). 

The questions in the rest of this section will help you develop measures and processes for assessing pressure ulcer rates and practices.

 

5.1 Measuring pressure ulcer rates

5.1.1 Why measure pressure ulcer rates?

Pressure ulcer rates are the most direct measure of how well you are succeeding in preventing pressure ulcers. If your rate is low or improving, then you are likely doing a good job in preventing pressure ulcers. Conversely, if your pressure ulcer rate is high or increasing, then there might be areas in which care can be improved. You can use these data to make a case for initiating a quality improvement effort and monitoring progress to sustain your improvements.

5.1.2 What should be counted?

In measuring pressure ulcer rates, you will be counting the number of patients with pressure ulcers. It is important that you only measure and track pressure ulcers. Many other types of skin lesions may develop in hospitalized patients. Remember, pressure ulcers are areas of soft tissue damage caused by pressure or pressure and shear. Do not count skin lesions not related to pressure such as skin breaks or maceration from friction/moisture, even when found over a bony prominence.

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Action Steps

Determine whether hospital staff can distinguish pressure ulcers from other causes of skin damage.

5.1.3 What measures do we use in monitoring pressure ulcer rates?

Two types of measures can be monitored: incidence and prevalence rates.

  • Incidence describes the number or percentage of people developing a new ulcer while in your facility or on your unit. Therefore, it only counts pressure ulcers developing after admission. Incidence rates provide the most direct evidence of the quality of your care. Therefore, your quality improvement efforts should focus on incidence rates.
  • Prevalence describes the number or percentage of people having a pressure ulcer while on your unit. It may reflect a single point in time, such as on the first day of each month. This is known as point prevalence. However, it can also reflect a prolonged period of time, such as an entire hospital stay. This is known as period prevalence. Both types of prevalence rates (point and period) include pressure ulcers present on admission as well as new ulcers that developed while in your facility or on your unit. Therefore, they can provide a useful snapshot of the pressure ulcer burden but they say less about your quality of preventive care than do incidence rates.

Make sure everyone looking at the data understands the difference between incidence and prevalence. Incidence rates capture only new pressure ulcers developing during an admission. Prevalence rates include all pressure ulcers present in a group of patients; those that developed during a hospital stay as well as those that developed elsewhere.

There is no single "right" approach to measuring pressure ulcer rates. Every approach has advantages and disadvantages. While we make specific recommendations below, the most important thing is to be consistent. Rates calculated by one approach or methodology cannot be compared to rates calculated another way.

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Action Steps

  • Assess whether unit staff understand the difference between incidence and prevalence rates and clarify understanding if they do not, using the definitions above.
  • Define the measurement approach that you will use.

5.1.4 What do we need to calculate pressure ulcer incidence or prevalence rates?

To calculate pressure ulcer incidence or prevalence rates, whether at the unit level or at the overall facility, you need to know who has a pressure ulcer and when it developed. To obtain this information, you must complete two tasks:

  • Perform a comprehensive skin inspection on every patient (go to section 3.2). Look carefully for any lesions of the skin and determine whether the lesion is a pressure ulcer. If unsure whether it is a pressure ulcer, get help from the wound care nurse or another experienced clinician.
  • Document the results of the comprehensive skin inspection on all patients. To calculate incidence or prevalence rates, you need to have the information on all patients easily available. Therefore, it is best if you use a standard form that lists each patient on the unit and the results of the daily skin inspection. This form notes whether there is a pressure ulcer, the number of different pressure ulcers, their location, and the stage of the deepest pressure ulcer.

While we recommend performing a comprehensive skin inspection daily and documenting the results on a standard form as the best approach for calculating pressure ulcer rates, hospitals have found it difficult to convince staff to create a new document for recording pressure ulcer status. Other approaches are possible that allow calculation of incidence and prevalence rates. One common approach is to pick a date, such as the first of the month, and perform a detailed skin examination of each patient. For each pressure ulcer present, the stage is described and it is determined whether the ulcer was present on admission. This approach allows the determination of both incidence and prevalence rates.

Typically, this comprehensive evaluation is performed by an "outside" expert such as a wound nurse or the nurse manager from another unit. The National Database of Nursing Quality Indicators (NDNQI) uses a similar approach, with assessments performed every 3 months. Whatever approach you select, use it consistently and always remember that rates calculated by different approaches are not comparable.

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Action Steps

Adopt or create a standard form on which you can easily record the results of the skin inspection. Some hospitals with electronic medical records have developed computerized skin assessment forms that must be completed daily on each patient.

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Tools

You can record the results of a skin inspection in a number of ways. A sample unit log for use in skin inspection documentation is included in Tools and Resources (Tool 5A, Floor Log).

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Resources

To learn how NDNQI recommends capturing data on pressure ulcers, refer to the survey guide in the section for pressure ulcer training at the NDNQI Web site: https://www.nursingquality.org/NDNQIPressureUlcerTraining/module3/Default.aspx.

5.1.5 How do we calculate pressure ulcer incidence or prevalence rates?

Incidence and prevalence rates should be calculated monthly based on the information from the skin inspection form. When using a standard form such as the one shown in Tools and Resources, at the end of the month count the total number of patients present, how many had a pressure ulcer at any time while on the unit, and how many developed a new ulcer while on the unit. In calculating rates, consider rates for all ulcers and those Stage II or greater.

Rates are calculated as follows:

  • PREVALENCE measures the number of patients with pressure ulcers at a certain point or period in time:
    • The numerator will be the number of patients with any pressure ulcer (count for both any ulcer and Stage II or greater).
    • Just count patients, not the number of ulcers. Even if a patient has four Stage II ulcers, he or she is only counted once.
    • The denominator is the number of patients on your unit or in your facility during that month.
    • Divide the numerator by the denominator and multiply by 100 to get the percentage.

      Example: 17 patients with any pressure ulcer ÷ 183 patients = .093 X 100 = 9.3 percent

  • INCIDENCE measures the number of patients developing new pressure ulcers during a period in time:
    • The numerator will be the number of patients who develop a new pressure ulcer (count all ulcers and those Stage II or greater) after admission
    • Just count patients, not the number of ulcers. Even if a patient has four Stage II ulcers, he or she is only counted once.
    • The denominator is the number of all patients admitted during that time period.
    • Sometimes in calculating incidence rates, studies have excluded patients with an existing pressure ulcer on admission. Neither approach is necessarily better; just be consistent.
    • Divide the numerator by the denominator and multiply by 100 to get the percentage.

      Example: 21 patients with a new pressure ulcer ÷ 227 patients = .093 X 100 = 9.3 percent

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Action Steps

  • Identify a person or team in the organization who will be responsible for these calculations.
  • Identify the sources of data that they will use. If current data are not available or not accurate, develop a strategy for improving data quality.

5.1.6 How should we use the monthly data on pressure ulcer rates?

Use the information on pressure ulcer rates that you collect in three ways. First, examine your rates every month and look at the trend over time. How are they changing? Are they improving or getting worse? Can you relate changes in your pressure ulcer rate to changes in practice? Think about what you have or have not been doing well over the past month and relate it to whether the incidence rate is better or worse.

Note that when you implement a quality improvement program and begin tracking performance, increased pressure ulcer rates are frequently seen. This is not necessarily related to worse care. Instead, unit staff members are becoming better at detecting pressure ulcers that were previously missed.

Second, disseminate this information to key stakeholders and to unit staff. Post monthly rates in places where all staff can see how the unit is doing. Send reports to leadership. Dissemination of information on performance is critical to your quality improvement effort.

Third, study in detail what led to the occurrence of each Stage III or IV pressure ulcer. When a deep pressure ulcer develops, it usually reflects not so much the failure of an individual clinician, but rather a system failure. Thus, these deep pressure ulcers represent a learning opportunity regarding aspects of care that may need improvement. Perhaps risk assessment was not done in a timely manner or care planning did not fully address the patient's skin care needs.

Try to understand why the pressure ulcer developed and how such incidence can be prevented in the future. Root cause analysis is a useful technique for understanding reasons for a failure in the system. Root cause analysis is a systematic process during which all factors contributing to an adverse event are studied and ways to improve care are identified. If you are not familiar with root cause analysis, work with your quality improvement department to learn how to conduct this analysis.

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Action Steps

  • Identify audiences for the data at different levels of the organization and determine through which paths you will provide the data. For example, for senior managers, report the data in a leadership meeting or performance improvement committee.
  • Assess whether unit staff know the unit's rate and whether it is improving over time.
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Additional Information

A more detailed description of root cause analysis is available at: http://psnet.ahrq.gov/primer.aspx?primerID=10.

5.1.7 Are there national benchmarks we can use for comparison with our pressure ulcer rates?

The question of how well we are we performing relative to other hospitals often arises. Are our rates lower than those at other hospitals? Unfortunately, there are no national benchmarks with which you can compare your performance. In large part this is due to the many different approaches used in studies measuring incidence and prevalence rates. Rates calculated using different approaches are not comparable.

There are a number of ongoing initiatives to determine pressure ulcer rates using a standardized method across a large number of hospitals. These include the NDNQI and periodic surveys by some of the large manufacturers of pressure relief devices, including Hill-Rom and KCI. In addition, as present on admission (POA) coding is implemented for pressure ulcers, the Centers for Medicare & Medicaid Services (CMS) databases will likely become a more accurate and useful source of data on national rates of pressure ulcer development in hospitals.

5.1.8 How can we improve the quality of the data being collected for pressure ulcer rates?

To improve data quality, you will need to improve staff recognition and staging of pressure ulcers. Many errors are made in the recognition and staging of pressure ulcers and there are only limited opportunities to learn. Therefore, consider performing a comprehensive skin assessment every 3 months with a wound care nurse or other knowledgeable clinician from another unit.

Consider collecting data on pressure ulcers developing after transfer from your unit. Pressure ulcers may take several days to develop after a severe pressure injury. Therefore, they may not be first noticed until after the patient has left your unit.

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Resources

Many resources have information on calculating pressure ulcer incidence and prevalence rates. Consider reviewing the following Web sites:

  • www.woundsinternational.com/pdf/content_24.pdf. This document describes the results from an expert working group on pressure ulcer incidence and prevalence rates. It is well written and easily understandable but may be too advanced for some people on your unit. Use it as a resource to answer any questions you may have.
  • https://www.nursingquality.org/NDNQIPressureUlcerTraining/module3/default.aspx. This Web page from the NDNQI contains a slide show describing a protocol for conducting a prevalence study. Also included are other measures of care that could be collected. The material is basic and will be understandable by most staff.
  • The National Pressure Ulcer Advisory Panel is preparing a slide presentation on calculating pressure ulcer prevalence and incidence rates. It will be available for purchase at their Web site at http://www.npuap.org. 

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5.2 Measuring key processes of care

5.2.1 Why measure key processes of care?

While measuring pressure ulcer rates is the ultimate test of how your facility or unit is performing, pressure ulcer rates are limited in that they do not tell you how to improve care. If your pressure ulcer rate is high, on what specific areas should you focus? To know where to focus improvement efforts, it is important to measure key processes of care. Many important processes of care could be measured in assessing pressure ulcer prevention. We recommend initially looking at no more than three:

  • Performance of comprehensive skin assessment within 24 hours of admission.
  • Performance of standardized risk assessment within 24 hours of admission.
  • Performance of care planning that addresses each deficit on standardized risk assessment.

5.2.2 What data sources should be used in measuring key processes of care?

In measuring key processes of care, data used in calculating performance rates can be obtained from a number of sources. These include direct observations of care, surveys of staff, and medical record reviews. Each approach has its strengths and limitations. Direct observation of care, where a trained observer determines whether a comprehensive skin assessment is done on a particular patient, would be the most accurate approach but would be extremely labor intensive. Surveys are also labor intensive and rely on staff members' recall of specific events. These recollections might be inaccurate. Medical record reviews are the easiest approach to complete but rely on what is documented in the record.

Much pressure ulcer preventive care may not be documented. Nonetheless, we recommend medical record reviews as the source of data on the performance of key processes of care. While rates may initially be low because of poor documentation, this finding will encourage improved documentation of the care actually being provided.

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Tools

Use this tool developed by the Quality Improvement Organization program for abstracting medical record data (Tool 5B, Preventing Pressure Ulcers Data Tool).

5.2.3 How do we ensure performance of comprehensive skin assessment within 24 hours of admission?

As the first step in prevention, it is essential to ensure that a comprehensive skin assessment is performed within 24 hours of admission. Determine whether this assessment is being performed.

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Tools

A sample protocol for checking skin assessments is available in Tools and Resources (Tool 5C, Assessing Comprehensive Skin Assessment).

5.2.4 How do we ensure performance of standardized risk assessment within 24 hours of admission?

Risk assessment is the cornerstone of prevention. It identifies whether patients are at risk and what specific interventions need to be implemented. Ensure that a standardized risk assessment was performed within 24 hours of admission.

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Tools

A sample protocol for checking risk assessments can be found in Tools and Resources (Tool 5D, Assessing Standardized Risk Assessment).

5.2.5 Howe do we assess care planning to ensure that it addresses each deficit on the standardized skin assessment?

For risk assessment to make a difference, all areas of risk identified on the standardized risk assessment need to be addressed in the care plans. Ensure that the care plans address all areas of risk.

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Tools

A sample protocol for assessing care plans can be found in Tools and Resources (Tool 5E, Assessing Care Planning).

5.2.6 What should be done if we are not doing well on measures of these key processes of care?

Good performance on these key processes of care is critical to preventing pressure ulcers. If you are not doing well, or as well as you would like, in one of these key areas, it provides an opportunity for improvement. Examine what the problem is and plan how to overcome this barrier. Go back to section 2.2 for suggestions on how to accomplish this goal. 

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5.3 Checklist for measuring progress

5. Checklist for measuring pressure ulcer rates and practices

Measuring pressure ulcer rates
  • Incidence and prevalence measures are frequently monitored
  • Pressure ulcer rates are examined on a monthly basis
  • Information on rates is disseminated to key stakeholders and staff
  • Root cause analysis is conducted for each occurrence of Stage III or IV pressure ulcer
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Measuring key processes of care
  • Comprehensive skin assessment is performed within 24 hours of admission
  • Standardized risk assessment is performed within 24 hours of admission
  • Care plan addressing every deficit on standardized risk assessment has been developed
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Current as of April 2011
Internet Citation: 5. How Do We Measure Our Pressure Ulcer Rates and Practices?: Preventing Pressure Ulcers in Hospitals: A Toolkit for Improving Quality of Care. April 2011. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/professionals/systems/long-term-care/resources/pressure-ulcers/pressureulcertoolkit/putool5.html