Clinical, Patient Factors Associated With Increased Odds of Appendectomy

Results of a cohort study found that that the presence of an appendicolith was associated with an approximately 2-fold increased risk for undergoing appendectomy within 30 days of initiating antibiotic treatment for appendicitis. These findings were published in JAMA Surgery.

The study was based on data from the comparison of outcomes of antibiotic drugs and appendectomy (CODA) randomized clinical trial (ClinicalTrials.gov Identifier: NCT02800785). Between May 2016 and February 2020, researchers conducted a cohort study at 25 medical centers that included a total of 1552 patients with acute appendicitis. The researchers sought to compare the clinical characteristics among patients who did and did not undergo appendectomy within 30 days of initiating antibiotics. Conditional logistic regression models were used to determine the associations between patient factors and the odds of undergoing appendectomy within 30 days of initiating antibiotics. In addition, the researchers performed a sensitivity analysis that excluded patients who underwent appendectomy for nonclinical reasons.

Among a total of 1552 patients included in the study, 776 received antibiotic treatment and 776 underwent appendectomy. Of patients treated with antibiotics, the mean age was 38.3 (SD, 13.4) years, 37% were women, and 63% were men. Among patients in the antibiotic group, 735 had 30-day outcomes, of whom 154 underwent appendectomy within 30 days.

After adjustment for patient sex, the researchers found that the odds of undergoing appendectomy within 30 days were increased among women (odds ratio [OR], 1.53; 95% CI, 1.01-2.31). Other factors associated with increased odds of undergoing appendectomy were a wider appendiceal diameter (OR per 1-mm increase, 1.14; 95% CI, 1.06-1.22) and presence of an appendicolith (OR, 2.56; 95% CI, 1.73-3.79). A total of 212 patients reported an appendicolith, of whom 65 underwent appendectomy within 30 days and 138 did not undergo the procedure.

The researchers found that the odds of undergoing appendectomy within 30 days were not associated with fever (OR, 1.28; 95% CI, 0.82-1.98) or other factors commonly used to determine appendicitis severity, including advanced age and comorbid conditions. Of note, the sensitivity analysis showed an increased association between presence of an appendicolith and odds of undergoing appendectomy within 30 days (OR, 2.41; 95% CI, 1.49-3.91).

This study was limited by the researchers’ inability to discern which patients underwent appendectomy due to antibiotic treatment failure vs other unmeasured factors.

According to the researchers, “these findings may be helpful in developing patient-facing tools to support informed decision-making in the treatment of appendicitis.”

Reference

Monsell SE, Voldal EC, Davidson GH, et al; Writing Group for the CODA Collaborative. Patient factors associated with appendectomy within 30 days of initiating antibiotic treatment for appendicitis. JAMA Surg. Published online January 12, 2022. doi:10.1001/jamasurg.2021.6900