Proactive Risk Assessment of Surgical Site Infection in Ambulatory Surgery Centers

Chapter 1. Introduction

Ambulatory surgery is a viable alternative to inpatient hospitalization for a range of invasive procedures. The volume and types of ambulatory surgery procedures continue to expand, providing testament to the overall safety and efficiency of surgery performed in these settings. Considering the authorization of Medicare payments for procedures performed in the ambulatory setting, it is not surprising that the number of ambulatory surgery centers (ASCs) also continues to expand. However, ASCs differ in their clinical organization, structure, and processes, potentially resulting in differences in patient care outcomes. Thus, despite their growing prevalence, there remain differences in ASC settings that may lead to the potential introduction of risk and subsequent harm to patients.

The performance of surgery involves risk regardless of the setting, personnel, and procedure. These risks can result in surgical mishaps, ranging from infections to wrong site surgeries. The risk for such adverse events increases when surgery is performed in an environment that is less regulated, more variable in its policies and procedures, and relatively understaffed. This occurs not only because the rates of known risks may be increased, but also because additional, perhaps unknown, risks resulting from a less regulated practice setting can be introduced into the performance of care.

Given that one of the greatest risks during the perioperative period is infection, infection control offers opportunity for potential mitigation of this risk. Infection control policies and procedures provide a basic set of principles governing the processes for surgical care. These principles are founded on evidence-based practices that are ritualistically performed before, during, and after every surgical procedure to ensure that infection risks are minimized. They include the surgical scrub, patient draping, sterilization, and patient preoperative risk factor management. Other important principles that contribute to an infection control plan include complex care practices such as appropriate patient selection and operative techniques; however, these additional principles may not be as well prescribed or "hardwired" into the patient care processes in ASCs because staff training, experience, and orientation vary across them and because these plans are not required by any licensing or accrediting body over ASCs. As a result, additional risk for infections may be inadvertently incorporated into the patient's care without a thorough understanding of how they contribute to surgical site infections (SSIs).

In August 2010, the Agency for Healthcare Research and Quality (AHRQ) commissioned a study to conduct a proactive risk assessment of SSIs within the ambulatory surgery setting. The American Institutes for Research (AIR) and its partners, Anthony M. Slonim, M.D., Dr.P.H., and the Virginia Polytechnic Institute and State University's ("Virginia Tech's") College of Engineering, were selected to conduct the study, which had two primary objectives:

  • Using a proactive risk assessment, identify the realm of risk factors associated with SSIs resulting from procedures performed at ASCs.
  • Design an intervention to mitigate the probability of SSIs for the most common risk factors for a particular surgical procedure, as identified by the proactive risk assessment.

To achieve a better understanding of how structural and process elements may affect the risk for SSIs in the ASC environment, we used a tool known as sociotechnical probabilistic risk assessment (ST-PRA). This tool allows us to incorporate risk estimates from the evidence-based literature and also to use experiential estimates from health care providers knowledgeable of the issues under consideration. ST-PRA is particularly helpful for estimating risks in outcomes that are very rare, such as the risk of SSI in the ambulatory surgery environment. Also important is the tool's utility in examining single-point failures, as well as combinations of events that lead to the outcome of interest (i.e., SSIs), thereby allowing the investigators to design interventions aimed at reducing the risks associated with failures in the performance of risk mitigation procedures.

This report highlights information presented in the previous interim report and all aspects of the project, including data collection through a literature review, analysis of existing databases, establishment of a technical expert panel (TEP), the development of the ST-PRA fault tree models, sensitivity analyses to determine the most important risks and combinations of risks, and the design of an intervention aimed at reducing the risk of SSIs. Finally, the report concludes with a discussion of the study's strengths and limitations and how the adoption of the intervention can contribute to improved patient safety. The report is divided into the following chapters:

  • ST-PRA Development.
  • Risk-Informed Intervention.
  • Conclusions and Next Steps.
Page last reviewed April 2013
Page originally created April 2013
Internet Citation: Chapter 1. Introduction. Content last reviewed April 2013. Agency for Healthcare Research and Quality, Rockville, MD.