Appendectomy versus nonoperative management of simple appendicitis: A post hoc analysis of an Eastern Association for the Surgery of Trauma multicenter study using a hierarchical ordinal scale

Background: Controversy exists about the preferred initial treatment of appendicitis. We sought to compare the two treatments for initial management of simple appendicitis.

Methods: In this post hoc analysis of the Multicenter Study for the Treatment of Appendicitis in America: Acute, Perforated, and Gangrenous database, subjects were divided into appendectomy or nonoperative management (NOM; antibiotics only or percutaneous drainage) cohorts. A novel topic-specific hierarchical ordinal scale was created with eight mutually exclusive categories: mortality, reoperation, other secondary interventions, readmission, emergency department visit, wound complication, surgical site infection, and no complication. Pairwise comparisons of American Association for the Surgery of Trauma Imaging Severity Grade 1 (simple appendicitis) patients were compared using win-lose-tie scoring and the sums of appendectomy/NOM groups were compared.

Results: A total 3,591 subjects were included: 3,262 appendectomy and 329 NOM, with significant differences in baseline characteristics between groups. Across 28 sites, the rate of NOM ranged from 0% to 48%, and the loss to follow-up rate was significantly higher for NOM compared with appendectomy (16.5% vs. 8.7%, p = 0.024). In the simple appendicitis hierarchical ordinal scale analysis, 2,319 subjects resulted in 8,714,304 pairwise comparisons; 75% of comparisons resulted in ties. The median (interquartile range) sums for the two groups are as follows: surgical, 400 (400-400), and NOM, 400 (-2,427 to 400) (p < 0.001). A larger proportion of appendectomy subjects (88.1%) had an outcome that was equivalent (or better) than at least half of the subjects compared with NOM subjects (NOM, 70.5%; OR [95% confidence interval], 0.3 [0.2-0.4]).

Conclusion: In contemporary American practice, appendectomy (compared with NOM) for simple appendicitis is associated with lower odds of developing clinically important unfavorable outcomes in the first year after illness.

Level of evidence: Therapeutic/Care Management; Level III.