Kao helps lead study on antibiotics for appendicitis

Dr. Lillian Kao -
Lillian Kao, MD, MS

Antibiotics are now an accepted first-line treatment for most people with appendicitis, according to final results of the Comparing Outcomes of antibiotic Drugs and Appendectomy (CODA) trial and an updated treatment guideline for appendicitis from the American College of Surgeons.

The CODA study findings are published in the New England Journal of Medicine.

Lillian Kao, MD, MS, professor and division chief of acute care surgery was a co-author on the paper in the NEJM.

“Although many surgeons may find that a 50-50 chance of appendectomy at 4 years to be unacceptably high, the CODA trial provides long-term outcomes data that allows providers to have informed discussions with patients to promote shared decision-making,” Kao said. “In particular, the CODA trial provides data on outcomes for patients with advanced appendicitis that were often excluded from other trials; this speaks to the real-world applicability of the results.”

“In the first 3 months after taking antibiotics for the condition, nearly 7 in 10 patients in the antibiotic group avoided an appendectomy. By 4 years, just under 50% had the surgery,” said David Flum, MD, co-principal investigator and professor and associate chair of surgery at the University of Washington School of Medicine. “Other outcomes favored either antibiotics or surgery. Putting it all together, antibiotics look to be the right treatment for many, but probably not all, patients with appendicitis.”

CODA is the largest-ever randomized clinical trial of appendicitis treatment. At 25 hospitals across 14 states, 1,552 patients with appendicitis consented to participate and were randomized to receive antibiotics or to undergo an appendectomy.

“While there were advantages and disadvantages to each treatment, we found that both treatments are safe, and patients will likely value these outcomes differently based on their unique symptoms, concerns, and circumstances,” Flum said.

Patients with an appendicolith, a calcified deposit found in about 25% of cases of acute appendicitis, were associated with more complications and a higher chance of appendectomy in the first 30 days. At 90 days out, however, there was no greater chance of appendectomy in patients with an appendicolith.

“Given these results and new treatment guidelines, it is important for surgeons and patients to discuss the pros and cons of both surgery and antibiotics in deciding on the treatment that’s best for that person at that time,” said Giana Davidson, MD, associate professor of surgery at the University of Washington and director of the CODA trial’s clinical coordinating center.

To foster those conversations, CODA investigators created an online decision-making tool for patients. It includes a video (currently in English and Spanish, with other languages to come) and a mechanism to help patients choose a direction that may better suit their individual circumstances.

“In the emergency setting, patients with appendicitis can make a treatment decision hurriedly,” Davidson said. “This online tool was built to help communicate the CODA results in lay terms and to spur a conversation between patients and surgeons about potential benefits and harms of each approach.”

Funded by the Patient-Centered Outcomes Research Institute (PCORI), the CODA study was conducted by a collaborative composed of surgeons and emergency medicine physicians, patient advisors, and other stakeholders.

A complete list of CODA collaborating institutions, investigators, and media contacts is available here.