Slide 1: Hello and welcome. Thank you for joining us. In this presentation, we are discussing the NHSN standardized utilization ratio – the SUR. We will discuss how it is calculated and how it can be used by organizations to assess device use, measure against national, state, and facility benchmarks and identify areas for improvement.
Slide 2 : The National Healthcare Safety Network (NHSN) is an electronic, integrated surveillance system used to collect comprehensive data about hospital acquired infections. The data then enables healthcare facilities to effectively identify problem areas and to focus efforts on process improvement and prevention. The SUR is a meaningful way to track device use which is essential to measuring exposure for device-associated infections. This learning module is approximately 15 minutes in length and can be viewed as needed. As NHSN reporting is complex and extensive, be sure to click on and review provided links and resources for more in-depth and nuanced definitions and application of criteria.
Slide 3 : After viewing this learning module, the learner will be able to identify and define the standardized utilization ratio as well as identify and understand how it can be applied as part of organizational assessments examining ways to improve device use in healthcare facilities. When reviewing, interpreting, and discussing the SUR, it is very easy to get caught up in the very tall weeds! The aim of this presentation is to break down the SUR into manageable chunks of understanding and provide a path to successful use of the SUR to understand device usage in your facility and develop meaningful improvement plans.
Slide 4 : The two documents on this slide cover all of what we are reviewing today. We will focus on the first document – The NHSN Standardized Utilization Ratio. The second document is the NHSN Patient Safety Component Manual in its entirety. If possible, it would be beneficial to your learning and comprehension to have the SUR document open and available as you continue this module. And be sure to download and save all documents for future use and reference.
Slide 5 : Prior to the development of the SUR, NHSN used what is called “device utilization ratio,” the DUR, to assess device use in healthcare organizations. However, the scope is narrow and does not reflect differences in other factors that may describe levels of device use, such as patient population or level of care. Additionally, the DUR loses comparability over time and across entities and is not able to accurately show overall performance for a given facility. On the other hand, the SUR, a ratio based on prediction – the likelihood or probability that something would happen -- can summarize data by more than one variable and adjust for differences in health organizations such as various facility and/or location-level factors that contribute to device use and have been found to be significantly associated with differences in device utilization. These differences include: bed size, physical location, medical affiliation, and facility type. This allows for more accurate comparisons of facilities to each other and to the state and national benchmarks. The SUR was developed using 2015 baseline NHSN data. Using a risk adjustment methodology (accounting for differences that may impact device use) and updated NHSN aggregated data (the compiled and summarized data hospitals provide used to create a statistical report that is able to make inferences about a given population) NHSN calculates specific SURs for unique facility and department types. To summarize, The SUR is a summary measure used to track device use at a national, state, local, facility, and/or unit level over time. Once calculated, a given facility or department’s SUR will not change. Organizations are not required to calculate the SUR but are expected to understand how it is calculated and how to interpret and use it correctly. Note, per the CDC, healthcare acquired devices or infections? definitions and protocols are expected to remain stable for several years, therefore, SURs will remain the same. Frequently updating the baseline would likely hinder the ability to measure progress and assess trends at the facility(?), local, state, and national levels.
Slide 6 : So why is the SUR important? The purpose of NHSN is to assist healthcare organizations in gathering and interpreting their data to address and eliminate hospital acquired infections. Again, tracking device use in healthcare settings is essential to measuring exposure for device-associated infections. The SUR compares the actual number of device days reported to what would be predicted given the standard population. It can then be used, in conjunction with other measures, to analyze and interpret healthcare associated infection data and develop successful action plans for improvement. Additionally, as stated previously, the SUR can be used to measure and compare device utilization across multiple planes, which can help identify best practices and capture improved quality care. Big picture, less device use equals lower likelihood of developing an infection. Through the SUR, organizations can assess their device utilization, acknowledge areas of best practice, and identify areas for improvement.
Slide 7 : The SUR is calculated by dividing the number of observed (actual) device days, as reported by the organization, by the number of predicted device days, as calculated by NHSN using a logistic regression model (determining relationships between two data factors). Again, organizations are not required to calculate the number of predicted device days or the SUR. They are required to report their number of observed device days and to understand how to interpret and use the SUR. NHSN will calculate a unique SUR for each organization, facility, and unit. Please note, the SUR can only be calculated when the number of predicted device days is greater than or equal to one. The SUR number provided can be anything greater than zero.
Slide 8 : Ok, so how do we interpret the SUR? It is important to remember that the SUR is a ratio, not a rate. It is evaluating the relationship between two data points – observed vs. predicted. It is not giving the rate at which device days occur. A SUR of greater than one indicates more device days were observed than predicted and a SUR of less than one indicates that fewer device days were observed than predicted. The SUR can also be interpreted through percentages. A SUR of 1.50 indicates the number of observed device days is fifty percent higher than the number of predicted. A SUR of 0.50 indicates the number of observed device days is fifty percent lower than the number of predicted. However, the SUR number alone does not imply statistical significance. This is important to understand. A facility can have a SUR above or below one and statistically, the facility’s performance is about the same as the national benchmark. This is where the p-value and confidence interval come into play.
Slide 9 : The p- value and confidence interval show if a given numeric value is statistically significant or not. The p-value is the statistical measure that indicates whether the number of observed device days is statistically significantly different than the predicted number of device days. So, a p-value of less than or equal to 0.05 indicates the number of observed device days is statistically significantly different than predicted. Meaning, the discrepancy is not likely by chance -- something is happening that is causing the unit or facility to experience increased device days. Again, increased device days leads to increased exposure, which leads to increased risk for harm to the patient. A p-value of greater than 0.05 indicates the number of observed days is not statistically significantly different than predicated. Meaning, the discrepancy is random, or by chance, and changes may not be indicated. The 95% confidence interval is the statistical range of values for which there is a high degree of confidence that the true SUR lies within that range. A confidence interval that does not include the value “one” indicates the number of observed device days is significantly different than the number of predicted device days. A confidence interval that does include the value of one indicates the number of observed device days is not significantly different than the number of predicted device days.
Slide 10 : Let’s work through an example. This example is from NHSN training. The first column will be the facility organizational or unit ID. The second column is the time frame. In this example, the time frame for the data being reviewed is quarter one 2016. Column three, is the number of observed device days for the given time frame, as reported by the facility. In this example, 1001. Column four is the number of predicted device days as calculated by NHSN. In this example, 604.392. Column five is the calculated SUR, 1.656. This indicates that approximately 66% more central line days were observed than predicted. But is this statistically significant? Meaning is there a concern that may need to be investigated? Columns six and seven are the p-value and confidence interval. This example shows the p-value to be below the significance level of 0.05 and the confidence interval does not include the value of one. From this, we can conclude the SUR is statistically significant – this facility observed a significantly different number of central line days than predicted. The next step is to ask why?
Slide 11 : When a facility is investigating and asking why, it is important to recognize the SUR is a tool well designed to assess for process improvement. But it is just that, a tool. A tool that tells part of the story. It is important to understand what is meaningful about the data provided and to look for and understand the rest of the story. For example, the overall facility SUR is not statistically significant, but the SUR at a unit level is. This is an opportunity for the organization to assess where device days can be reduced and where to focus process improvement initiatives. It is important that facilities get into the consistent habit of internally tracking and trending monthly or quarterly data and as compared with SUR data over time. This allows for prompt response to identification and opportunities for invention to concerns. Also, it is important to recognize where a SUR number is coming from. For example, it is expected that observed device days in an intensive care unit would be higher than the observed device days in a rehab unit. But is the specific unit SUR number indicating an investigation into device utilization practices may be needed? Routine analysis and interpretation of data helps support an organization’s ability to make meaningful operational decisions to improve patient care and outcomes. And be sure to share organizational and department progress and celebrate the wins!
Slide 12 : Specific analysis reports can be created from user generated datasets and can be displayed and visualized in various ways to assist facilities with identifying opportunities for improvement. This can be particularly helpful when engaging with physicians and other care providers regarding process changes. Relaying data in ways that are meaningful to them and speak directly to their practice can go a long way in cultivating buy-in and sustainability.
Slide 13 : And remember, above all, individuals matter. Indwelling medical devices expose patients to a higher risk of infection. While they are often medically necessary, they are not without risk. Prolonged device days increases a patient’s risk for infection. And one hospital acquired infection means one person was hurt. And one family was affected. The SUR is a vital tool in a facility’s process improvement arsenal. But be sure not to get lost in the numbers and forget to consider the person in the hospital bed.
Slide 14 : Explore these additional resources for further and more in-depth instruction on NHSN reporting practices and requirements. Please note, while the SIR and the SUR are evaluating two different relationships, the mathematical functions are the same.
Slide 15 : Thank you for viewing this video. Remember, you can contact NHSN anytime with questions and clarifications at nhsn@cdc.gov. Let’s get to work!
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