Project Summary

PCORI funds implementation projects to promote the use of findings from PCORI-funded studies. This project focuses on implementing findings from the completed PCORI-funded research project: Comparing Surgery versus Antibiotics to Treat Appendicitis -- The CODA Study.

1. What were the results from the original PCORI-funded research study?

The recently completed CODA trial compared antibiotic therapy as an alternative to appendectomy for the treatment of appendicitis in a diverse population of more than 1,500 patients with almost all types of presentations of appendicitis. The CODA trial found that antibiotics were noninferior to, or just as good as, appendectomy, when considering the outcome of general health status (measured by the EQ5D quality-of-life questionnaire) at 30 days and that approximately 7 of 10 antibiotics-assigned participants were able to avoid appendectomy in the early period. This result was also observed in a parallel study of a group of patients who chose either antibiotics or appendectomy, suggesting the generalizability of the results.

There were also subgroups with substantially better or worse outcomes with one or the other treatment and contextual factors related to a patient’s situation and health needs that may make surgery or antibiotics a better option for some patients.

The CODA results were incorporated into national guidelines for appendicitis care by the American College of Surgeons (ACS) that now state, “antibiotics are an accepted first-line treatment,” and ACS recommendations that patients be informed of the risk/benefits of both treatment options and have their preferences and priorities elicited as part of an individualized clinical decision-making process.

2. Why is this research finding important?

Findings from the European trials excluded patients with radiologic evidence of perforation or an appendicolith (calcified stool within the appendix) and required long hospitalizations for treatment. These studies did not appreciably influence the practices of US surgeons, with a 2015 study from California finding fewer than 5 percent of patients with appendicitis received nonoperative treatment. While CODA’s findings led to immediate changes to national recommendations in appendicitis care during the COVID-19 pandemic, the trial also identified several barriers to implementation that need to be addressed.

Patient-level barriers include:

  • Not knowing antibiotics are an option
  • Fear of recurrence
  • Misinformation about the risk that the appendix will “burst” if not removed
  • Limited access to the hospital if needed once they return home
  • Caregiving responsibilities
  • Insurance concerns
  • Limited ability to advocate for a nonoperative approach

Clinician-level barriers include:

  • Beliefs about the risk of complications
  • Lack of knowledge and inexperience managing patients on antibiotics with ongoing symptoms
  • Inability to monitor for clinical worsening or lack of structures and personnel in the clinic to ensure appropriate follow-up
  • Loss of revenue associated with appendectomy

Health system barriers include:

  • Need for operational protocols for treatment
  • Follow-up care
  • Limited experience with shared decision making in the acute care setting
  • Questions about financial impact for health systems

3. What is the goal of this project?

The Treatment Individualized Appendicitis Decision Making (TRIAD) implementation program is a barrier-informed, multicomponent/multilevel strategy that will lead to more informed decision making and better outcomes related to antibiotics for appendicitis. TRIAD is an implementation strategy that includes: (1) a patient-facing decision aid (, (2) a clinician and allied health professional training program, and (3) a system-level, operational protocol to support treatment decisions.

4. What is the project team doing?

The project team will conduct an implementation of TRIAD at 15 hospitals, involving more than 2,500 patients. This includes a train the trainer activity for three-member teams at each site and deployment of the operational protocol and decision aid. The team will conduct formative and summative evaluations, including baseline and follow-up assessments of patients, clinicians/staff, and health systems. Anticipated findings include:

  • Increased patient-level awareness of treatment options, less decisional conflict (main outcome measure), and less decisional regret/dissatisfaction when choosing antibiotics
  • Improvements in clinician/staff knowledge, self-efficacy related to prescribing antibiotics, frequency of offering antibiotics, and greater awareness of patient preferences
  • More routine follow-up care, less emergency department time for patients, and greater use of support services

5. How is the team evaluating this project?

Using the RE-AIM framework, the quantitative analysis will measure reach (the proportion of patients with appendicitis at each implementation site that uses the decision aid) and effectiveness (change in decisional conflict among patients treated at sites before versus after implementation of TRIAD). Other quantitative analyses will be descriptive and used to support exploratory subgroup analyses including those related to use of antibiotics and outcomes (patient surveys at 30 days), including outcomes used in the CODA trial (e.g., EQ5D, decisional regret, rate of appendectomy after antibiotics).

The qualitative component will measure adoption (the number, proportion, and representativeness of clinicians and sites willing to take up the intervention and reasons for adoption/nonadoption measured by surveys of clinician self-efficacy related to offering antibiotics, knowledge and attitudes about antibiotic treatment for appendicitis, frequency of offering antibiotics, and elicitation of patient preferences), implementation (fidelity, measured at the system-level through surveys assessing adherence to protocol for follow-up care, change in time spent in the emergency department for patients with appendicitis, changes in services and staffing related to the implementation, and change in appendectomy procedural volume), and maintenance (the extent to which TRIAD continues after implementation and reasons for continuation measured through surveys, interviews, and focus groups).

6. How is the team involving patients and others in making sure the findings reach people who can use them?

TRIAD implementation will be guided by patient, clinician, and national (e.g., professional society) advisory committees. The 15-member CODA Patient Advisory Network and 30-member CODA Clinician Advisory Network helped develop the decision aid and will support TRIAD. As project partners, patient advisors work alongside the project team to inform all aspects of the project. The clinical advisory board includes site investigators at all practice sites (acute care general surgeons and emergency medicine physicians; letters of support provided). They will participate in quarterly meetings of the Clinician Advisory Board throughout the project timeline and collaborate with the project team to facilitate appropriate tailoring of TRIAD elements based on local context.

The National Advisory Board comprises leaders from professional societies for surgery, emergency medicine, and family medicine (e.g., ACS, the Surgical Infection Society, the American College of Emergency Physicians, and the Association of Academic Chairs in Emergency Medicine) that have been engaged through the CODA/TRIAD advisory boards. These organizations along with the leaders of six statewide/regional National Surgical Quality Improvement Initiative collaboratives will help develop the next phase of national implementation of TRIAD based on the success of this 15-site implementation project.

7. How will this project help ensure future uptake and use of findings from patient-centered outcomes research?

To support a nationwide implementation, TRIAD will be deployed and assessed in nonresearch settings, with adaptation based on local context. Qualitative evaluations conducted before implementation (baseline) and during the first 12 months of implementation will be used for refinements (e.g., revisions/improvements to educational materials that participants find confusing and troubleshooting logistical issues such as infrastructure needs that are unreliable and need solutions) aimed at maximizing effectiveness in different settings. Qualitative evaluations conducted after implementation will assess unintended consequences, the degree to which TRIAD functions are being maintained, and what drives heterogeneity in maintenance.

TRIAD has significant support for next-phase efforts directed at nationwide implementation. The ACS leadership and leaders of six statewide/regional surgical quality improvement collaboratives will serve on TRIAD’s national advisory board. Based on the success of this 15-site implementation project, the project team anticipates nationwide implementation across ACS’s 700-hospital National Surgical Quality Improvement Program collaborative and the six statewide/regional surgical quality improvement collaboratives.

Project Information

David Flum, MD, MPH
Giana Davidson, MD, MPH
University of Washington
$2,044,997 *

Key Dates

36 months *

Initial PCORI-Funded Research Study

This implementation project focuses on putting findings into practice from this completed PCORI-funded research study: Comparing Surgery versus Antibiotics to Treat Appendicitis -- The CODA Study

*All proposed projects, including requested budgets and project periods, are approved subject to a programmatic and budget review by PCORI staff and the negotiation of a formal award contract.


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Last updated: August 5, 2022